Carbon-doped copper ferrite(C–CuFe_(2)O_(4))was synthesized by a simple two-step hydrothermal method,which showed enhanced tetracycline hydrochloride(TCH)removal efficiency as compared to the pure CuFe_(2)O_(4) in Fe...Carbon-doped copper ferrite(C–CuFe_(2)O_(4))was synthesized by a simple two-step hydrothermal method,which showed enhanced tetracycline hydrochloride(TCH)removal efficiency as compared to the pure CuFe_(2)O_(4) in Fenton-like reaction.A removal efficiency of 94%was achieved with 0.2 g L^(-1) catalyst and 20 mmol L^(-1) H_(2)O_(2) within 90 min.We demonstrated that 5%C–CuFe_(2)O_(4) catalyst in the presence of H_(2)O_(2) was significantly efficient for TCH degradation under the near-neutral pH(5–9)without buffer.Multiple techniques,including SEM,TEM,XRD,FTIR,Raman,XPS M€ossbauer and so on,were conducted to investigate the structures,morphologies and electronic properties of as-prepared samples.The introduction of carbon can effectively accelerate electron transfer by cooperating with Cu and Fe to activate H_(2)O_(2) to generate·OH and·O_(2)^(-).Particularly,theoretical calculations display that the p,p,d orbital hybridization of C,O,Cu and Fe can form C–O–Cu and C–O–Fe bonds,and the electrons on carbon can transfer to metal Cu and Fe along the C–O–Fe and C–O–Cu channels,thus forming electron-rich reactive centers around Fe and Cu.This work provides lightful reference for the modification of spinel ferrites in Fenton-like application.展开更多
TiO2-seashell composites prepared via a sol-gel method were used to generate carbonate radicals(·CO3–) under solar light irradiation. ·CO3–, a selective radical, was employed to degrade the target tetracyc...TiO2-seashell composites prepared via a sol-gel method were used to generate carbonate radicals(·CO3–) under solar light irradiation. ·CO3–, a selective radical, was employed to degrade the target tetracycline hydrochloride contaminant. A series of characterizations was carried out to study the structure and composition of the synthesized TiO2-seashell composite. This material exhibits excellent solar light-driven photochemical activity in the decomposition of tetracycline hydrochloride. The possible pathway and mechanism for the photodegradation process were proposed on the basis of high-resolution electrospray ionization time-of-flight mass spectrometry experiments. Finally, we investigated the reusability of the TiO2-seashell composite. This study is expected to provide a new facile pathway for the application of ·CO3– radicals to degrade special organic pollutants in water.展开更多
We tested the utility of chemical marking techniques in the juvenile black rockfish Sebastes schlegelii. Juveniles (30-40 mm total length) were immersed in a range of tetracycline hydrochloride (TC) solutions at c...We tested the utility of chemical marking techniques in the juvenile black rockfish Sebastes schlegelii. Juveniles (30-40 mm total length) were immersed in a range of tetracycline hydrochloride (TC) solutions at concentrations ranging from 300 to 500 mg/L, and alizarin complexone (ALC) solutions at concentrations ranging from 200 to 400 mg/L in filtered sea water (salinity of 30) for 24 h, respectively. Otoliths (sagittae, asteriscus), scales, fin rays (dorsal, pectoral, ventral, anal, and caudal fin rays), and fin spines (dorsal, ventral, and anal fin spines) were sampled and used to detect fluorescent marks after a 60-day growth experiment. With the exception of 300 mg/L TC, acceptable marks were produced in the otoliths and fin spines by all concentrations of TC and ALC. In particular, we observed clearly visible marks in the sagittae, asteriscus, and fin spines under normal light at concentrations of200~00 mg/L, 250-400 mg/L, and 250-400 mg/L ALC, respectively. Scales and fin rays had acceptable marks at much higher concentrations (_〉350 mg/L TC, 〉250 mg/L ALC for scales and _〉350 mg/L TC, 〉300 mg/L ALC for fin rays). The best mark quality (i.e., acceptable marks were observed in all sampled structures after immersion marking) were obtained following immersion in TC at between 350-500 rag/L, and ALC between 300-400 mg/L. In addition, there was no significant difference in survival and growth of TC and ALC marked fish compared to their controls up to 60 days post-marking (P〉0.05).展开更多
g-C3N4 is a hot visible light photocatalyst. However, the fast recombination of photogenerated electron- hole pairs leads to unsatisfactory photocatalytic efficiencies. In this study, Mg/O co-decorated amorphous carbo...g-C3N4 is a hot visible light photocatalyst. However, the fast recombination of photogenerated electron- hole pairs leads to unsatisfactory photocatalytic efficiencies. In this study, Mg/O co-decorated amorphous carbon nitride (labeled as MgO-CN) with a unique electronic structure was designed and prepared via a combined experimental and theoretical approach. The results showed that the MgO-CN exhibited an increased light absorption ability and promoted charge separation efficiency. The Mg and O co-decoration created a unique structure that could generate localized electrons around O atoms and enhance the reactant activation capacities via the C→O←Mg route. This could dramatically promote the O2 molecule activation on the catalyst surface to generate reactive species (?O2 –/?OH). The optimized MgO-CN exhibited a high photocatalytic activity for the degradation of tetracycline hydrochloride in water, which was five times higher than that of pristine g-C3N4. The present work could provide a new strategy for modifying the electronic structure of g-C3N4 and enhancing its performance for environmental applications.展开更多
A novel and effective BiOCl0.9I0.1/x%β-Bi2O3 composite catalyst was synthesized through a precipitation method. The structure, morphology, and optical properties of the samples were certified by X-ray diffraction, UV...A novel and effective BiOCl0.9I0.1/x%β-Bi2O3 composite catalyst was synthesized through a precipitation method. The structure, morphology, and optical properties of the samples were certified by X-ray diffraction, UV-Vis diffuse reflectance, scanning electron microscopy, and X-ray photoelectron spectroscopic characterizations. Photocatalytic experiments demonstrated that the synthesized BiOCl0.9I0.1/x%β-Bi2O3 composite catalyst exhibited excellent photocatalytic performance toward the degradation of tetracycline hydrochloride(TCH) under simulated sunlight. Furthermore, the TCH degradation rate of BiOCl0.9I0.1/15%β-Bi2O3 increased by 27.6% and 61.4% compared with those of the pure BiOCl0.9I0.1 and pure β-Bi2O3, respectively. Due to the multiple vacancies and valence states possessed by BiOCl0.9I0.1/x%β-Bi2O3, namely Bi5+, Bi(3-x)+, Bi5+–O, Bi3+–O, I- and I3-, the charge separation in photocatalysis reactions can be effectively promoted. The Mott-Schottky measurements indicate that the conduction band(CB) level of BiOCl0.9I0.1/15%β-Bi2O3 becomes more negative relative to that of BiOCl0.9I0.1, guaranteeing an advantageous effect on the redox ability of the photocatalyst. This study provides a new bright spot for the construction of high-performance photocatalysts.展开更多
Porous g-C3N4samples were obtained by simply calcining bulk g-C3N4in static air in a muffle oven.The photocatalytic performance of these samples was evaluated through the removal of aqueous organic dyes(methylene blu...Porous g-C3N4samples were obtained by simply calcining bulk g-C3N4in static air in a muffle oven.The photocatalytic performance of these samples was evaluated through the removal of aqueous organic dyes(methylene blue and methyl orange)and tetracycline hydrochloride under visible-light irradiation(λ〉420 nm).Compared to bulk g-C3N4,porous g-C3N4exhibited much better capability for removing these contaminants,especially under visible-light irradiation,due to the enlarged specific surface area and more efficient separation of photogenerated charge carries.In particular,porous g-C3N4obtained by calcining bulk g-C3N4in air at 525℃ showed the highest visible-light-driven catalytic activity among these samples.Superoxide radical anions(·O2^-)were found to be the primary active species responsible for photodegradation.展开更多
In vitro dissolution kinetics of a-tricalcium phosphate (α-TCP) cement and α-TCP cement containing tetracycline Hydrochloride(TTCH) were studied in the present paper. It shows that dissolution process of α-TCP ...In vitro dissolution kinetics of a-tricalcium phosphate (α-TCP) cement and α-TCP cement containing tetracycline Hydrochloride(TTCH) were studied in the present paper. It shows that dissolution process of α-TCP cement and TTCH-loaded α-TCP cement accords with Avrami dissolution kinetics model: x=1-exp(-kt^n), and Avrami constant n is 0.5 and 0.4 respectively, which means dissolution process is diffusion control. Apparent dissolution activation energy of α-TCP cement and TTCH-loaded α-TCP cement is about 9.87 kJ/moland 7.17 kJ/mol respectively. Comparing with α-TCP cement, activation energy and Avrami constant of TTCH-loaded α-TCP cement decrease slightly, but its [Ca^2+] solubility decreases from 40 ppm to 11.5 ppm, which could result from the change of interracial property and morphology of hydrated apatite crystal caused by absorption of TTCH on the apatite.展开更多
α- and β-Ga2O3 were prepared via a precipitation method. The as-prepared α- and β-Ga2O3 were characterized by X-ray diffraction (XRD), N2-sorption BET surface area, UV-vis diffuse reflectance spectra (DRS), ph...α- and β-Ga2O3 were prepared via a precipitation method. The as-prepared α- and β-Ga2O3 were characterized by X-ray diffraction (XRD), N2-sorption BET surface area, UV-vis diffuse reflectance spectra (DRS), photoluminescence spectroscopy (PL) and electron spin resonancespectroscopy (ESR). The photocatalytic activities of Ga2O3 were evaluated by the photocatalytic degradation of tetracycline sydrochloride solution. The results showed that the photocatalytic activity of β-Ga2O3 was higher than that of α-Ga2O3 and β-Ga2O3 obtained at the calcination temperature of 900℃, which showed the best photocatalytic activity. The reasons for the differences in photocatalytic activity of Ga2O3 are discussed in terms of crystallinity, surface area, crystals and electronic structures.展开更多
The removal of antibiotic pollutants remaining in the environmental media has been a big challenge nowadays.Herein,we report a facile and green approach to fabricate an eco-friendly composite membrane without addition...The removal of antibiotic pollutants remaining in the environmental media has been a big challenge nowadays.Herein,we report a facile and green approach to fabricate an eco-friendly composite membrane without addition of any toxic polymers or chemical cross-linking agents to effectively remove the tetracycline hydrochloride in Water.Firstly,the sulfated cellulose nanocrystalline(CNC) was obtained via hydrolysis of sulfuric acid by using microcrystalline cellulose(MCC) as raw material under ultrasonic condition.The as-prepared CNC has a nanowhisker dimension with 200.2 ± 110.2 nm in length,15.7 ± 9.3 nm in width,and 7.2 ± 3.1 nm in height.The obtained CNC is cellulose type I as determined by X-ray diffraction(XRD),while its crystallinity index(Crl) can reach 82.3%.Then,the composite membrane derived from the obtained CNC and commercial mixed cellulose ester(MCE)membrane was facilely prepared through vacuum dewatering process,which is applied to remove tetracycline hydrochloride(Th) in solution.The results showed that the removal efficiency of Th through the neat MCE was only28 ± 4%,while it could be improved to 58 ± 5% and 89 11%,respectively,by filtering through composite membranes with different contents of CNC deposition.Such effect is derived from the combine factors based on both steric hindrance(sieving) and electrostatic interaction(Donnan) effect of the composite membranes.The development of related CNC materials and composite fabrication processes is in favor of cost-effective and "green"polymer composites for the remediation of increasing antibiotic pollution and the purification of contaminated water nowadays.展开更多
It is important to investigate whether combining two modification strategies has a synergistic effect on the activity of photocatalysts.In this manuscript,Fe-doped BiOBr/Bi_(2)WO_(6) heterojunctions were synthesized b...It is important to investigate whether combining two modification strategies has a synergistic effect on the activity of photocatalysts.In this manuscript,Fe-doped BiOBr/Bi_(2)WO_(6) heterojunctions were synthesized by a one-pot solvothermal method,and excellent photocatalytic performance was obtained for the degradation of tetracycline hydrochloride(TCH)in water without the addition of surfactant.Combining experiments and characterization,the synergistic effect between Fe ion doping and the BiOBr/Bi_(2)WO_(6) heterojunction was elucidated.The Fe/BiOBr/Bi_(2)WO_(6) composite photocatalyst had a beneficial void structure,enhanced visible light response,and could inhibit the recombination of photogenerated support well,which improved the photocatalytic activity.The presented experiments demonstrate that Fe/BiOBr/Bi_(2)WO_(6) removes 97% of TCH from aqueous solution,while pure BiOBr and Bi_(2)WO_(6) only remove 56% and 65% of TCH,respectively.Finally,the separation and transfer mechanisms of photoexcited carriers were determined in conjunction with the experimental results.This study provides a new direction for the design of efficient photocatalysts through the use of a dual co-modification strategy.展开更多
Peracetic acid(CH_(3)C(O)OOH,PAA)-based heterogeneous advanced oxidation process(AOP)has attacked intensive interests due to production of various reactive species.Herein,Co(OH)_(2)nanoparticles decorated biochar(Co(O...Peracetic acid(CH_(3)C(O)OOH,PAA)-based heterogeneous advanced oxidation process(AOP)has attacked intensive interests due to production of various reactive species.Herein,Co(OH)_(2)nanoparticles decorated biochar(Co(OH)_(2)/BC)was fabricated by a simple and controllable method,which was used to degrade tetracycline hydrochloride(TTCH)in water through PAA activation.The results indicated that 100%TTCH(C_(0)=10μmol/L)degradation efficiency was realized within 7 min at pH 7,with a high kinetic rate constant(k_(1))of 0.64 min^(-1)by the optimized Co(OH)_(2)/BC.Material characterizations suggested that Co(OH)_(2)nanoparticle was successfully decorated on biochar,leading to more active sites and electronic structure alteration of biochar,thus greatly promoting the catalytic cleavage of PAA for radicals production.Then,the reactive oxygen species(ROS)quenching experiments and electron paramagnetic resonance(EPR)analysis demonstrated the key species were alkoxyl radicals(R–O^(·),mainly CH_(3)CO_(2)^(·)and CH_(3)CO_(3)^(·)),HO^(·)and^(1)O_(2)in this system.Besides,density functional theory(DFT)calculation on Fukui index further revealed that the vulnerable sites of TTCH and three possible degradation pathways were proposed.This study can provide a new strategy for synthesis functional materials in PAA activation AOPs for removal of antibiotics in water.展开更多
In this study,a graphitic carbon nitride(g-C_(3)N_(4))based ternary catalyst Cu O/Cu Fe_(2)O_(4)/gC_(3)N_(4)(CCCN)is successfully prepared thorough calcination method.After confirming the structure and composition of ...In this study,a graphitic carbon nitride(g-C_(3)N_(4))based ternary catalyst Cu O/Cu Fe_(2)O_(4)/gC_(3)N_(4)(CCCN)is successfully prepared thorough calcination method.After confirming the structure and composition of CCCN,the as-synthesized composites are utilized to activate persulfate(PS)for the degradation of organic contaminant.While using tetracycline hydrochloride(TC)as pollutant surrogate,the effects of initial p H,PS and catalyst concentration on the degradation rate are systematically studied.Under the optimized reaction condition,CCCN/PS is able to give 99%degradation extent and 74%chemical oxygen demand removal in assistance of simulated solar light,both of which are apparently greater than that of either Cu O/Cu Fe_(2)O_(4)and pristine g-C_(3)N_(4).The great improvement in degradation can be assignable to the effective separation of photoinduced carriers thanks to the integration between Cu O/Cu Fe_(2)O_(4)and g-C_(3)N_(4),as well as the increased reaction sites given by the g-C_(3)N_(4)substrate.Moreover,the scavenging trials imply that the major oxidative matters involved in the decomposition are hydroxyl radicals(·OH),superoxide radicals(·O_(2)^(-))and photo-induced holes(h^(+)).展开更多
TiO_(2)/graphene oxide(GO)as photocatalyst in the photo-degradation of multitudinous pollutants has been extensively studied.But its low photocatalytic efficiency is attributed to the high band gap energy which lead t...TiO_(2)/graphene oxide(GO)as photocatalyst in the photo-degradation of multitudinous pollutants has been extensively studied.But its low photocatalytic efficiency is attributed to the high band gap energy which lead to low light utilization.Cu-TiO_(2)/GO was synthesized via the impregnation methods to enhance the catalytic performance.The Cu-TiO_(2)/GO reaction rate constant for photo-degradation of pollutants(tetracycline hydrochloride,TC)was about 1.4 times that of TiO_(2)/GO.In 90 min,the removal ratio of Cu-TiO_(2)/GO for TC was 98%,and the maximum degradation ratio occurred at p H 5.After five cycles,the removal ratio of Cu-Ti O_(2)/GO still exceeded 98%.UV-visible adsorption spectra of Cu-Ti O_(2)/GO showed that its band gap was narrower than TiO_(2)/GO.Electron paramagnetic resonance(EPR)spectra test illustrated the generation rate of·O_(2)^(-)and·OH was higher in Cu-TiO_(2)/GO system than TiO_(2)/GO and TiO_(2) system.The contribution sequence of oxidative species was·O_(2)^(-)>holes(h+)>·OH in both TiO_(2)/GO and Cu-Ti O_(2)/GO system.Interestingly,the contribution of·OH in Cu-TiO_(2)/GO was less than that in TiO_(2)/GO during the photo-degradation process.This phenomenon was attributed to the better adsorption performance of Cu-Ti O_(2)/GO which could reduce the accessibility of TC to·OH in liquid.The enhanced non-hydroxyl radical contribution could be attributed to that the more other active species or sites on(nearby)the surface of Cu-TiO_(2)/GO generated after doping Cu.These results provide a new perspective for the tradition metal-doped conventional catalysts to enhance the removal of organic pollutants in the environment.展开更多
The unique heterojunction photocatalyst of graphite carbon nitride (g-C_(3)N_(4)) modified ultrafine TiO_(2) (g-C_(3)N_(4)/TiO_(2)) was successfully fabricated by electrochemical etching and co-annealing method. Howev...The unique heterojunction photocatalyst of graphite carbon nitride (g-C_(3)N_(4)) modified ultrafine TiO_(2) (g-C_(3)N_(4)/TiO_(2)) was successfully fabricated by electrochemical etching and co-annealing method. However, the effects of various environmental factors on the degradation of TC by g-C_(3)N_(4)/TiO_(2) and the internal reaction mechanism are still unclear. In this study, the effects of initial pH, anions, and cations on the photocatalytic degradation of tetracycline hydrochloride (TC) by g-C_(3)N_(4)/TiO_(2) were systematically explored, and the scavenging experiment and intermediate detection were conducted to better reveal the mechanism on photocatalytic degradation of TC. The results showed that the removal efficiency of photocatalytic degradation of TC by g-C_(3)N_(4)/TiO_(2) could reach 99.04% under Xenon lamp irradiation within 120 min. The unique g-C_(3)N_(4)/TiO_(2) heterojunction photocatalyst showed excellent photocatalytic performance for the degradation of TC at pH 3~7, and possesses outstanding anti-interference ability to NO_(3)^(-), Cl^(-), Na^(+), Ca^(2+) and Mg^(2+) ions in natural waters during the photocatalytic degradation TC process. Superoxide radicals (O_(2)^(·-)) and hydroxyl radicals (^(·)OH) were proved as the main reactive species for TC degradation, and the possible mechanism of the unique photocatalytic system for g-C_(3)N_(4)/TiO_(2) was also proposed. The above results can provide a reliable basis and theoretical guidance for the design and application of visible photocatalyst with high activity to degrade the actual wastewater containing TC.展开更多
p-block metal composite oxides Sr_(1.36)Sb_(2)O_(6) and Sr_(2)Sb_(2)O_(7) synthesized by a hydrothermal method as photocatalysts in the degradation of tetracycline hydrochloride under UV light irradiation have been ex...p-block metal composite oxides Sr_(1.36)Sb_(2)O_(6) and Sr_(2)Sb_(2)O_(7) synthesized by a hydrothermal method as photocatalysts in the degradation of tetracycline hydrochloride under UV light irradiation have been extensively studied.The effects of synthesis conditions on the photocatalytic activity were discussed.The Sr_(1.36)Sb_(2)O_(6)-100°C-24 h-5 and Sr_(2)Sb_(2)O_(7)-150℃-24 h^(-2) samples prepared under optimal conditions exhibited remarkably different photocatalytic activities.The essential factors influencing the difference of photocatalytic performance were revealed.The results showed that the different photocatalytic activities observed for Sr_(1.36)Sb_(2)O_(6)and Sr_(2)Sb_(2)O_(7) could be attributed to their different electronic and crystal structures.Our work will provide a new perspective for the screening and design of p-block metal composite oxide photocatalysts to enhance the removal of organic pollutants in the environment.展开更多
Photooxidative removal of pharmaceuticals and organic dyes is an effective way to eliminate growing micropollutants. However, photooxidation often results in byproducts as secondary hazardous substances such as phytot...Photooxidative removal of pharmaceuticals and organic dyes is an effective way to eliminate growing micropollutants. However, photooxidation often results in byproducts as secondary hazardous substances such as phytotoxins. Herein, we found that photooxidation of common antibiotic tetracycline hydrochloride(TCH) over a metal-free 8-hydroxyquinoline(8-HQ) functionalized carbon nitride(CN) photocatalyst significantly reduces the TCH phytotoxic effect. The phytotoxicity test of photocatalytic treated TCH-solution evaluated towards seed growth of Cicer arietinum plant model endowed natural root and shoot growth.This study highlights the conceptual insights in designing of metal-free photocatalyst for environmental remediation.展开更多
Construction of heterojunctions is a normal and effective strategy to improve the photocatalytic performances of semiconductors,through which both the lifetime and the redox ability of electrons/holes can be improved,...Construction of heterojunctions is a normal and effective strategy to improve the photocatalytic performances of semiconductors,through which both the lifetime and the redox ability of electrons/holes can be improved,as co mpared to the respective component.On this basis,we constructed Z-scheme CdS/LaFeO_(3) heterojunctions(CdS/LFO),by in-situ growing different amounts of CdS on the surface of LaFeO_(3),for photocatalytic degradation of tetracycline hydrochloride(TC)in aqueous solution at room temperature.The crystal structure,surface morphology and optoelectronic properties of the COS/LFO heterojunctions were systemically characterized to correlate the reaction activity.Photocatalytic tests indicate that the CdS/LFO heterojunctions exhibit promising activity for TC degradation under visible light irradiation(λ≥420 nm),with 85%TC conversion obtained at reaction time of 45 min,which is 3.4 and 1.9 times higher than that of CdS and LaFeO_(3).The CdS/LFO heterojunctions are also stable in the reaction and can be reused for four cycles with no appreciable activity loss.The applicability of CdS/LFO to photocatalytic degradation of organic dyes,as well as the reaction mechanism,was also explored.展开更多
Novel black oxygen deficient bismuth oxide(Bi_(2)O_(3)-Bi_(2)O_(3-x))photocatalytic material was successfully prepared by a two zone temperature controlled muffle furnace method.The lanthanum,cerium and erbium ions ar...Novel black oxygen deficient bismuth oxide(Bi_(2)O_(3)-Bi_(2)O_(3-x))photocatalytic material was successfully prepared by a two zone temperature controlled muffle furnace method.The lanthanum,cerium and erbium ions are successfully doped into Bi_(2)O_(3)-Bi_(2)O_(3-x) with the average contents of 10.77 wt%,7.62 wt%and 8,14 wt%,respectively.The re sults show that a large number of oxygen vacancies exist in Bi_(2)O_(3)-Bi_(2)O_(3-x).La^(3+)Ce^(3+)and Er^(3+)act as electron acceptors to temporarily trap the photo-generated electrons.The XPS spectrum show Bi-O band in Bi_(2)O_(3)-Bi_(2)O_(3-x) and the O 1s peak of Ce/Bi_(2)O_(3)-Bi_(2)O_(3-x) move toward the direction of low binding energy.These phenomena fully prove that the separation of photogenerated electron-hole pairs will be more effectual,so as to reduce the possibility of charge carrier recombination.The radical scavenging experiments and electron spin resonance detections confirm that the conduction band of the original Bi_(2)O_(3)can easily receive photogenerated electrons,while the valence band of the modified Bi_(2)O_(3)-Bi_(2)O_(3-x) tends to accept photogenerated holes and then forms the circulation system.Therefore,Ce/Bi_(2)O_(3)-Bi_(2)O_(3-x) can degrade tetracycline hydrochloride up to 90.15%.This research provides some new insights into developing green and recyclable photocatalysts for the remediation of antibiotic contamination.展开更多
The major findings in this report are(ⅰ)development of nanocomposite photocatalyst working through Z-scheme charge transfer pathway across the heterojunction,(ⅱ)utilization of direct sunlight as the photo-source,and...The major findings in this report are(ⅰ)development of nanocomposite photocatalyst working through Z-scheme charge transfer pathway across the heterojunction,(ⅱ)utilization of direct sunlight as the photo-source,and(ⅲ)prospect of ligand-hole in photocatalysis through enhanced sub-band gap absorption,The photocatalysts,namely LaNiO_(3),g-C_(3)N_(4) and LaNiO_(3)/g-C_(3)N_(4) nanocomposites were synthesized via facile route and were characterized for their structure,morphology,microstructure,texture,elemental mapping and surface oxidation states by using several physicochemical techniques.The photocatalytic performance of the nanocomposite was tested through the degradation of hazardous azo dye pollutants,namely reactive black 5 and methylene blue as well as the colorless antibiotic-pollutant tetracycline hydrochloride in aqueous solution in presence of natural sunlight with excellent recycling activity.The 10%LaNiO_(3)/g-C_(3)N_(4) nanocomposite sample shows the best catalytic activity,degrading respectively 94%,98.6%and 88.1%of reactive black 5,methylene blue and tetracycline hydrochloride in60,180 and 120 min.The photocatalytic activity of the nanocomposite phase is several times superior to that of the pure phases.The improvements of photocatalytic activity of g-C_(3)N_(4) in the nanocomposite have been rationalized through the construction of direct Z-scheme heterojunction and suppression of electron-hole pair recombination efficiency.The enhanced photo-absorption of the nanocomposite can possibly be related to sub-bandgap absorption,which is associated to the midgap state originating from ligand-hole formation or defects in the structure.The photodegradation process is mediated through the formation of super oxide radical(O_(2))and hole(h^(+))as the main responsible species.展开更多
The degradation of pharmaceutical micropollutants is an intensifying environmental problem and synthesis of efficient photocatalysts for this purpose is one of the foremost challenges worldwide.Therefore,this study wa...The degradation of pharmaceutical micropollutants is an intensifying environmental problem and synthesis of efficient photocatalysts for this purpose is one of the foremost challenges worldwide.Therefore,this study was conducted to develop novel plasmonic Ag/Ag2O/BiVO4 nanocomposite photocatalysts by simple precipitation and thermal decomposition methods,which could exhibit higher photocatalytic activity for mineralized pharmaceutical micropollutants.Among the different treatments,the best performance was observed for the Ag/Ag2O/BiVO4 nanocomposites (5 wt.%;10 min’s visible light irradiation)which exhibited 6.57 times higher photodegradation rate than the pure BiVO4.Further,the effects of different influencing factors on the photodegradation system of tetracycline hydrochloride (TC-HCl) were investigated and the feasibility for its practical application was explored through the specific light sources,water source and cycle experiments.The mechanistic study demonstrated that the photogenerated holes (h^+),superoxide radicals (·O2^-)and hydroxyl radicals (·OH) participated in TC-HCl removal process,which is different from the pure BiVO4 reaction system.Hence,the present work can provide a new approach for the formation of novel plasmonic photocatalysts with high photoactivity and can act as effective practical application for environmental remediation.展开更多
基金supported by the Program for the National Natural Science Foundation of China(52070077,51879101,51779090)the National Program for Support of Top-Notch Young Professionals of China(2014)+1 种基金the Program for Changjiang Scholars and Innovative Research Team in University(IRT-13R17)Natural Science Foundation of Hunan Province(2022JJ20013,2021JJ40098).
文摘Carbon-doped copper ferrite(C–CuFe_(2)O_(4))was synthesized by a simple two-step hydrothermal method,which showed enhanced tetracycline hydrochloride(TCH)removal efficiency as compared to the pure CuFe_(2)O_(4) in Fenton-like reaction.A removal efficiency of 94%was achieved with 0.2 g L^(-1) catalyst and 20 mmol L^(-1) H_(2)O_(2) within 90 min.We demonstrated that 5%C–CuFe_(2)O_(4) catalyst in the presence of H_(2)O_(2) was significantly efficient for TCH degradation under the near-neutral pH(5–9)without buffer.Multiple techniques,including SEM,TEM,XRD,FTIR,Raman,XPS M€ossbauer and so on,were conducted to investigate the structures,morphologies and electronic properties of as-prepared samples.The introduction of carbon can effectively accelerate electron transfer by cooperating with Cu and Fe to activate H_(2)O_(2) to generate·OH and·O_(2)^(-).Particularly,theoretical calculations display that the p,p,d orbital hybridization of C,O,Cu and Fe can form C–O–Cu and C–O–Fe bonds,and the electrons on carbon can transfer to metal Cu and Fe along the C–O–Fe and C–O–Cu channels,thus forming electron-rich reactive centers around Fe and Cu.This work provides lightful reference for the modification of spinel ferrites in Fenton-like application.
文摘TiO2-seashell composites prepared via a sol-gel method were used to generate carbonate radicals(·CO3–) under solar light irradiation. ·CO3–, a selective radical, was employed to degrade the target tetracycline hydrochloride contaminant. A series of characterizations was carried out to study the structure and composition of the synthesized TiO2-seashell composite. This material exhibits excellent solar light-driven photochemical activity in the decomposition of tetracycline hydrochloride. The possible pathway and mechanism for the photodegradation process were proposed on the basis of high-resolution electrospray ionization time-of-flight mass spectrometry experiments. Finally, we investigated the reusability of the TiO2-seashell composite. This study is expected to provide a new facile pathway for the application of ·CO3– radicals to degrade special organic pollutants in water.
基金Supported by the Special Fund for Agro-Scientific Research in the Public Interest(No.201003068)the National Natural Science Foundation of China(Nos.31172447,41176117)
文摘We tested the utility of chemical marking techniques in the juvenile black rockfish Sebastes schlegelii. Juveniles (30-40 mm total length) were immersed in a range of tetracycline hydrochloride (TC) solutions at concentrations ranging from 300 to 500 mg/L, and alizarin complexone (ALC) solutions at concentrations ranging from 200 to 400 mg/L in filtered sea water (salinity of 30) for 24 h, respectively. Otoliths (sagittae, asteriscus), scales, fin rays (dorsal, pectoral, ventral, anal, and caudal fin rays), and fin spines (dorsal, ventral, and anal fin spines) were sampled and used to detect fluorescent marks after a 60-day growth experiment. With the exception of 300 mg/L TC, acceptable marks were produced in the otoliths and fin spines by all concentrations of TC and ALC. In particular, we observed clearly visible marks in the sagittae, asteriscus, and fin spines under normal light at concentrations of200~00 mg/L, 250-400 mg/L, and 250-400 mg/L ALC, respectively. Scales and fin rays had acceptable marks at much higher concentrations (_〉350 mg/L TC, 〉250 mg/L ALC for scales and _〉350 mg/L TC, 〉300 mg/L ALC for fin rays). The best mark quality (i.e., acceptable marks were observed in all sampled structures after immersion marking) were obtained following immersion in TC at between 350-500 rag/L, and ALC between 300-400 mg/L. In addition, there was no significant difference in survival and growth of TC and ALC marked fish compared to their controls up to 60 days post-marking (P〉0.05).
基金supported by the Specialized Innovation of Social and People’s Livelihood in Chongqing(cstc2016shmszx20012)Converting Outstanding Achievements of University-Funded Projects of Chongqing(KJZH17122)+3 种基金the National Natural Science Foundation of China(5160080705)the Key Laboratory Open Project from Chongqing Technology and Business University(1556036)Innovative Research Project from Chongqing Technology and Business University(yjscxx2016-060-34)the Scientific and Technological Research Program of Chongqing Municipal Education Commission(KJ130704)~~
文摘g-C3N4 is a hot visible light photocatalyst. However, the fast recombination of photogenerated electron- hole pairs leads to unsatisfactory photocatalytic efficiencies. In this study, Mg/O co-decorated amorphous carbon nitride (labeled as MgO-CN) with a unique electronic structure was designed and prepared via a combined experimental and theoretical approach. The results showed that the MgO-CN exhibited an increased light absorption ability and promoted charge separation efficiency. The Mg and O co-decoration created a unique structure that could generate localized electrons around O atoms and enhance the reactant activation capacities via the C→O←Mg route. This could dramatically promote the O2 molecule activation on the catalyst surface to generate reactive species (?O2 –/?OH). The optimized MgO-CN exhibited a high photocatalytic activity for the degradation of tetracycline hydrochloride in water, which was five times higher than that of pristine g-C3N4. The present work could provide a new strategy for modifying the electronic structure of g-C3N4 and enhancing its performance for environmental applications.
文摘A novel and effective BiOCl0.9I0.1/x%β-Bi2O3 composite catalyst was synthesized through a precipitation method. The structure, morphology, and optical properties of the samples were certified by X-ray diffraction, UV-Vis diffuse reflectance, scanning electron microscopy, and X-ray photoelectron spectroscopic characterizations. Photocatalytic experiments demonstrated that the synthesized BiOCl0.9I0.1/x%β-Bi2O3 composite catalyst exhibited excellent photocatalytic performance toward the degradation of tetracycline hydrochloride(TCH) under simulated sunlight. Furthermore, the TCH degradation rate of BiOCl0.9I0.1/15%β-Bi2O3 increased by 27.6% and 61.4% compared with those of the pure BiOCl0.9I0.1 and pure β-Bi2O3, respectively. Due to the multiple vacancies and valence states possessed by BiOCl0.9I0.1/x%β-Bi2O3, namely Bi5+, Bi(3-x)+, Bi5+–O, Bi3+–O, I- and I3-, the charge separation in photocatalysis reactions can be effectively promoted. The Mott-Schottky measurements indicate that the conduction band(CB) level of BiOCl0.9I0.1/15%β-Bi2O3 becomes more negative relative to that of BiOCl0.9I0.1, guaranteeing an advantageous effect on the redox ability of the photocatalyst. This study provides a new bright spot for the construction of high-performance photocatalysts.
基金Supported by the National Natural Science Foundation of China(Grant No.21477022)
文摘Porous g-C3N4samples were obtained by simply calcining bulk g-C3N4in static air in a muffle oven.The photocatalytic performance of these samples was evaluated through the removal of aqueous organic dyes(methylene blue and methyl orange)and tetracycline hydrochloride under visible-light irradiation(λ〉420 nm).Compared to bulk g-C3N4,porous g-C3N4exhibited much better capability for removing these contaminants,especially under visible-light irradiation,due to the enlarged specific surface area and more efficient separation of photogenerated charge carries.In particular,porous g-C3N4obtained by calcining bulk g-C3N4in air at 525℃ showed the highest visible-light-driven catalytic activity among these samples.Superoxide radical anions(·O2^-)were found to be the primary active species responsible for photodegradation.
基金Supported by the National Natural Science Foundation of China (No.50772045)
文摘In vitro dissolution kinetics of a-tricalcium phosphate (α-TCP) cement and α-TCP cement containing tetracycline Hydrochloride(TTCH) were studied in the present paper. It shows that dissolution process of α-TCP cement and TTCH-loaded α-TCP cement accords with Avrami dissolution kinetics model: x=1-exp(-kt^n), and Avrami constant n is 0.5 and 0.4 respectively, which means dissolution process is diffusion control. Apparent dissolution activation energy of α-TCP cement and TTCH-loaded α-TCP cement is about 9.87 kJ/moland 7.17 kJ/mol respectively. Comparing with α-TCP cement, activation energy and Avrami constant of TTCH-loaded α-TCP cement decrease slightly, but its [Ca^2+] solubility decreases from 40 ppm to 11.5 ppm, which could result from the change of interracial property and morphology of hydrated apatite crystal caused by absorption of TTCH on the apatite.
基金supported by the Funds of Department of Education of Fujian province(No.JA14199)
文摘α- and β-Ga2O3 were prepared via a precipitation method. The as-prepared α- and β-Ga2O3 were characterized by X-ray diffraction (XRD), N2-sorption BET surface area, UV-vis diffuse reflectance spectra (DRS), photoluminescence spectroscopy (PL) and electron spin resonancespectroscopy (ESR). The photocatalytic activities of Ga2O3 were evaluated by the photocatalytic degradation of tetracycline sydrochloride solution. The results showed that the photocatalytic activity of β-Ga2O3 was higher than that of α-Ga2O3 and β-Ga2O3 obtained at the calcination temperature of 900℃, which showed the best photocatalytic activity. The reasons for the differences in photocatalytic activity of Ga2O3 are discussed in terms of crystallinity, surface area, crystals and electronic structures.
基金financially supported by the Tianjin Science and Technology Committee Major Project Program(18ZXJMTG00070)
文摘The removal of antibiotic pollutants remaining in the environmental media has been a big challenge nowadays.Herein,we report a facile and green approach to fabricate an eco-friendly composite membrane without addition of any toxic polymers or chemical cross-linking agents to effectively remove the tetracycline hydrochloride in Water.Firstly,the sulfated cellulose nanocrystalline(CNC) was obtained via hydrolysis of sulfuric acid by using microcrystalline cellulose(MCC) as raw material under ultrasonic condition.The as-prepared CNC has a nanowhisker dimension with 200.2 ± 110.2 nm in length,15.7 ± 9.3 nm in width,and 7.2 ± 3.1 nm in height.The obtained CNC is cellulose type I as determined by X-ray diffraction(XRD),while its crystallinity index(Crl) can reach 82.3%.Then,the composite membrane derived from the obtained CNC and commercial mixed cellulose ester(MCE)membrane was facilely prepared through vacuum dewatering process,which is applied to remove tetracycline hydrochloride(Th) in solution.The results showed that the removal efficiency of Th through the neat MCE was only28 ± 4%,while it could be improved to 58 ± 5% and 89 11%,respectively,by filtering through composite membranes with different contents of CNC deposition.Such effect is derived from the combine factors based on both steric hindrance(sieving) and electrostatic interaction(Donnan) effect of the composite membranes.The development of related CNC materials and composite fabrication processes is in favor of cost-effective and "green"polymer composites for the remediation of increasing antibiotic pollution and the purification of contaminated water nowadays.
基金supported by the Hunan Provincial Natural Science Foundation of China(No.2021JJ30728 and 2019JJ50672)the Scientific Research Projects of Ecology and Environment Department of Hunan(No.HBKT-2021012)the Water Conservancy Science and Technology Project of Hunan Province(Nos.XSKJ2022068-03 and XSKJ2019081-46)are highly appreciated。
文摘It is important to investigate whether combining two modification strategies has a synergistic effect on the activity of photocatalysts.In this manuscript,Fe-doped BiOBr/Bi_(2)WO_(6) heterojunctions were synthesized by a one-pot solvothermal method,and excellent photocatalytic performance was obtained for the degradation of tetracycline hydrochloride(TCH)in water without the addition of surfactant.Combining experiments and characterization,the synergistic effect between Fe ion doping and the BiOBr/Bi_(2)WO_(6) heterojunction was elucidated.The Fe/BiOBr/Bi_(2)WO_(6) composite photocatalyst had a beneficial void structure,enhanced visible light response,and could inhibit the recombination of photogenerated support well,which improved the photocatalytic activity.The presented experiments demonstrate that Fe/BiOBr/Bi_(2)WO_(6) removes 97% of TCH from aqueous solution,while pure BiOBr and Bi_(2)WO_(6) only remove 56% and 65% of TCH,respectively.Finally,the separation and transfer mechanisms of photoexcited carriers were determined in conjunction with the experimental results.This study provides a new direction for the design of efficient photocatalysts through the use of a dual co-modification strategy.
基金supported by the National Key Research and Development Program of China(Nos.2022YFF1303102 and 2021YFA1202500)Beijing Natural Science Foundation(No.8232035)+2 种基金the National Natural Science Foundation of China(Nos.52270053,52200083 and 52200084)the Beijing Nova Program(No.20220484215)the Key Special Projects for Science and Technology of Inner Mongolia(No.2021EEDSCXSFQZD001)。
文摘Peracetic acid(CH_(3)C(O)OOH,PAA)-based heterogeneous advanced oxidation process(AOP)has attacked intensive interests due to production of various reactive species.Herein,Co(OH)_(2)nanoparticles decorated biochar(Co(OH)_(2)/BC)was fabricated by a simple and controllable method,which was used to degrade tetracycline hydrochloride(TTCH)in water through PAA activation.The results indicated that 100%TTCH(C_(0)=10μmol/L)degradation efficiency was realized within 7 min at pH 7,with a high kinetic rate constant(k_(1))of 0.64 min^(-1)by the optimized Co(OH)_(2)/BC.Material characterizations suggested that Co(OH)_(2)nanoparticle was successfully decorated on biochar,leading to more active sites and electronic structure alteration of biochar,thus greatly promoting the catalytic cleavage of PAA for radicals production.Then,the reactive oxygen species(ROS)quenching experiments and electron paramagnetic resonance(EPR)analysis demonstrated the key species were alkoxyl radicals(R–O^(·),mainly CH_(3)CO_(2)^(·)and CH_(3)CO_(3)^(·)),HO^(·)and^(1)O_(2)in this system.Besides,density functional theory(DFT)calculation on Fukui index further revealed that the vulnerable sites of TTCH and three possible degradation pathways were proposed.This study can provide a new strategy for synthesis functional materials in PAA activation AOPs for removal of antibiotics in water.
基金financially supported by the National Natural Science Foundation of China(Nos.21663027 and 21808189)the Key Science and Technology Foundation of Gansu Province(No.20YF3GA021)+2 种基金the Innovation funding program of Universities of Gansu province(No.2020B-091)the Opening Project of Key Laboratory of Green Chemistry of Sichuan Institutes of Higher Education(No.LYJ18205)the Promotion Project of Young-Teacher Research-capacity of Northwest Normal University(No.NWNU-LKQN-18-5)。
文摘In this study,a graphitic carbon nitride(g-C_(3)N_(4))based ternary catalyst Cu O/Cu Fe_(2)O_(4)/gC_(3)N_(4)(CCCN)is successfully prepared thorough calcination method.After confirming the structure and composition of CCCN,the as-synthesized composites are utilized to activate persulfate(PS)for the degradation of organic contaminant.While using tetracycline hydrochloride(TC)as pollutant surrogate,the effects of initial p H,PS and catalyst concentration on the degradation rate are systematically studied.Under the optimized reaction condition,CCCN/PS is able to give 99%degradation extent and 74%chemical oxygen demand removal in assistance of simulated solar light,both of which are apparently greater than that of either Cu O/Cu Fe_(2)O_(4)and pristine g-C_(3)N_(4).The great improvement in degradation can be assignable to the effective separation of photoinduced carriers thanks to the integration between Cu O/Cu Fe_(2)O_(4)and g-C_(3)N_(4),as well as the increased reaction sites given by the g-C_(3)N_(4)substrate.Moreover,the scavenging trials imply that the major oxidative matters involved in the decomposition are hydroxyl radicals(·OH),superoxide radicals(·O_(2)^(-))and photo-induced holes(h^(+)).
基金the National Natural Science Foundation of China(No.41772264)the Applied Basic Research Programs of Science and Technology Foundation of Sichuan Province(No.18YYJC1745)the Research Fund of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection(No.SKLGP2018Z001)。
文摘TiO_(2)/graphene oxide(GO)as photocatalyst in the photo-degradation of multitudinous pollutants has been extensively studied.But its low photocatalytic efficiency is attributed to the high band gap energy which lead to low light utilization.Cu-TiO_(2)/GO was synthesized via the impregnation methods to enhance the catalytic performance.The Cu-TiO_(2)/GO reaction rate constant for photo-degradation of pollutants(tetracycline hydrochloride,TC)was about 1.4 times that of TiO_(2)/GO.In 90 min,the removal ratio of Cu-TiO_(2)/GO for TC was 98%,and the maximum degradation ratio occurred at p H 5.After five cycles,the removal ratio of Cu-Ti O_(2)/GO still exceeded 98%.UV-visible adsorption spectra of Cu-Ti O_(2)/GO showed that its band gap was narrower than TiO_(2)/GO.Electron paramagnetic resonance(EPR)spectra test illustrated the generation rate of·O_(2)^(-)and·OH was higher in Cu-TiO_(2)/GO system than TiO_(2)/GO and TiO_(2) system.The contribution sequence of oxidative species was·O_(2)^(-)>holes(h+)>·OH in both TiO_(2)/GO and Cu-Ti O_(2)/GO system.Interestingly,the contribution of·OH in Cu-TiO_(2)/GO was less than that in TiO_(2)/GO during the photo-degradation process.This phenomenon was attributed to the better adsorption performance of Cu-Ti O_(2)/GO which could reduce the accessibility of TC to·OH in liquid.The enhanced non-hydroxyl radical contribution could be attributed to that the more other active species or sites on(nearby)the surface of Cu-TiO_(2)/GO generated after doping Cu.These results provide a new perspective for the tradition metal-doped conventional catalysts to enhance the removal of organic pollutants in the environment.
基金financially supported by National Natural Science Foundation of China (Nos. 52070107, 51678323)Natural Science Foundation of Shandong Province (Nos. ZR2019MD012,ZR2017MEE026)+1 种基金Support Plan on Youth Innovation Science and Technology for Higher Education of Shandong Province (No.2019KJD014)Natural Science Foundation of Heilongjiang Province (No. B2015024)。
文摘The unique heterojunction photocatalyst of graphite carbon nitride (g-C_(3)N_(4)) modified ultrafine TiO_(2) (g-C_(3)N_(4)/TiO_(2)) was successfully fabricated by electrochemical etching and co-annealing method. However, the effects of various environmental factors on the degradation of TC by g-C_(3)N_(4)/TiO_(2) and the internal reaction mechanism are still unclear. In this study, the effects of initial pH, anions, and cations on the photocatalytic degradation of tetracycline hydrochloride (TC) by g-C_(3)N_(4)/TiO_(2) were systematically explored, and the scavenging experiment and intermediate detection were conducted to better reveal the mechanism on photocatalytic degradation of TC. The results showed that the removal efficiency of photocatalytic degradation of TC by g-C_(3)N_(4)/TiO_(2) could reach 99.04% under Xenon lamp irradiation within 120 min. The unique g-C_(3)N_(4)/TiO_(2) heterojunction photocatalyst showed excellent photocatalytic performance for the degradation of TC at pH 3~7, and possesses outstanding anti-interference ability to NO_(3)^(-), Cl^(-), Na^(+), Ca^(2+) and Mg^(2+) ions in natural waters during the photocatalytic degradation TC process. Superoxide radicals (O_(2)^(·-)) and hydroxyl radicals (^(·)OH) were proved as the main reactive species for TC degradation, and the possible mechanism of the unique photocatalytic system for g-C_(3)N_(4)/TiO_(2) was also proposed. The above results can provide a reliable basis and theoretical guidance for the design and application of visible photocatalyst with high activity to degrade the actual wastewater containing TC.
基金financially supported by the National Natural Science Foundation of China(21875037,51502036)the National Key Research and Development Program of China(2016YFB0302303,2019YFC1908203)the Natural Science Foundation of Distinguished Young Scholars of Fujian Province(2019J06015)。
文摘p-block metal composite oxides Sr_(1.36)Sb_(2)O_(6) and Sr_(2)Sb_(2)O_(7) synthesized by a hydrothermal method as photocatalysts in the degradation of tetracycline hydrochloride under UV light irradiation have been extensively studied.The effects of synthesis conditions on the photocatalytic activity were discussed.The Sr_(1.36)Sb_(2)O_(6)-100°C-24 h-5 and Sr_(2)Sb_(2)O_(7)-150℃-24 h^(-2) samples prepared under optimal conditions exhibited remarkably different photocatalytic activities.The essential factors influencing the difference of photocatalytic performance were revealed.The results showed that the different photocatalytic activities observed for Sr_(1.36)Sb_(2)O_(6)and Sr_(2)Sb_(2)O_(7) could be attributed to their different electronic and crystal structures.Our work will provide a new perspective for the screening and design of p-block metal composite oxide photocatalysts to enhance the removal of organic pollutants in the environment.
基金the department of science and technology fund for improvement of science and technology infrastructure (DST FIST) (No. SR/FST/CSI-279/2016(C)) for providing XRD and UV-DRS facilitiesthe department of science and technology science and engineering research board (DST-SERB) through the project (No. SB/EMEQ-052/2014 SERB) for financial assistancethe Director, Visvesvaraya National Institute of Technology (VNIT) Nagpur for financial support。
文摘Photooxidative removal of pharmaceuticals and organic dyes is an effective way to eliminate growing micropollutants. However, photooxidation often results in byproducts as secondary hazardous substances such as phytotoxins. Herein, we found that photooxidation of common antibiotic tetracycline hydrochloride(TCH) over a metal-free 8-hydroxyquinoline(8-HQ) functionalized carbon nitride(CN) photocatalyst significantly reduces the TCH phytotoxic effect. The phytotoxicity test of photocatalytic treated TCH-solution evaluated towards seed growth of Cicer arietinum plant model endowed natural root and shoot growth.This study highlights the conceptual insights in designing of metal-free photocatalyst for environmental remediation.
基金Project supported by the National Natural Science Foundation of China(21976141,42277485)the Department of Science and Technology of Hubei Province(2021CFA034)+1 种基金the Department of Education of Hubei Province(T2020011)the Opening Project of Hubei Key Laboratory of Biomass Fibers and Eco-dyeing&Finishing(STRZ202202)。
文摘Construction of heterojunctions is a normal and effective strategy to improve the photocatalytic performances of semiconductors,through which both the lifetime and the redox ability of electrons/holes can be improved,as co mpared to the respective component.On this basis,we constructed Z-scheme CdS/LaFeO_(3) heterojunctions(CdS/LFO),by in-situ growing different amounts of CdS on the surface of LaFeO_(3),for photocatalytic degradation of tetracycline hydrochloride(TC)in aqueous solution at room temperature.The crystal structure,surface morphology and optoelectronic properties of the COS/LFO heterojunctions were systemically characterized to correlate the reaction activity.Photocatalytic tests indicate that the CdS/LFO heterojunctions exhibit promising activity for TC degradation under visible light irradiation(λ≥420 nm),with 85%TC conversion obtained at reaction time of 45 min,which is 3.4 and 1.9 times higher than that of CdS and LaFeO_(3).The CdS/LFO heterojunctions are also stable in the reaction and can be reused for four cycles with no appreciable activity loss.The applicability of CdS/LFO to photocatalytic degradation of organic dyes,as well as the reaction mechanism,was also explored.
基金Project supported by the National Natural Science Foundation of China(51966003)Innovation Project of Guangxi Graduate Education(YCBZ2020065)Natural Science Foundation of Guangxi Province(2018GXNSFDA050004)。
文摘Novel black oxygen deficient bismuth oxide(Bi_(2)O_(3)-Bi_(2)O_(3-x))photocatalytic material was successfully prepared by a two zone temperature controlled muffle furnace method.The lanthanum,cerium and erbium ions are successfully doped into Bi_(2)O_(3)-Bi_(2)O_(3-x) with the average contents of 10.77 wt%,7.62 wt%and 8,14 wt%,respectively.The re sults show that a large number of oxygen vacancies exist in Bi_(2)O_(3)-Bi_(2)O_(3-x).La^(3+)Ce^(3+)and Er^(3+)act as electron acceptors to temporarily trap the photo-generated electrons.The XPS spectrum show Bi-O band in Bi_(2)O_(3)-Bi_(2)O_(3-x) and the O 1s peak of Ce/Bi_(2)O_(3)-Bi_(2)O_(3-x) move toward the direction of low binding energy.These phenomena fully prove that the separation of photogenerated electron-hole pairs will be more effectual,so as to reduce the possibility of charge carrier recombination.The radical scavenging experiments and electron spin resonance detections confirm that the conduction band of the original Bi_(2)O_(3)can easily receive photogenerated electrons,while the valence band of the modified Bi_(2)O_(3)-Bi_(2)O_(3-x) tends to accept photogenerated holes and then forms the circulation system.Therefore,Ce/Bi_(2)O_(3)-Bi_(2)O_(3-x) can degrade tetracycline hydrochloride up to 90.15%.This research provides some new insights into developing green and recyclable photocatalysts for the remediation of antibiotic contamination.
基金Project supported by the Science and Engineering Research Board(SERB),Government of India(EMR/2016/001811,EMR/2016/000083)。
文摘The major findings in this report are(ⅰ)development of nanocomposite photocatalyst working through Z-scheme charge transfer pathway across the heterojunction,(ⅱ)utilization of direct sunlight as the photo-source,and(ⅲ)prospect of ligand-hole in photocatalysis through enhanced sub-band gap absorption,The photocatalysts,namely LaNiO_(3),g-C_(3)N_(4) and LaNiO_(3)/g-C_(3)N_(4) nanocomposites were synthesized via facile route and were characterized for their structure,morphology,microstructure,texture,elemental mapping and surface oxidation states by using several physicochemical techniques.The photocatalytic performance of the nanocomposite was tested through the degradation of hazardous azo dye pollutants,namely reactive black 5 and methylene blue as well as the colorless antibiotic-pollutant tetracycline hydrochloride in aqueous solution in presence of natural sunlight with excellent recycling activity.The 10%LaNiO_(3)/g-C_(3)N_(4) nanocomposite sample shows the best catalytic activity,degrading respectively 94%,98.6%and 88.1%of reactive black 5,methylene blue and tetracycline hydrochloride in60,180 and 120 min.The photocatalytic activity of the nanocomposite phase is several times superior to that of the pure phases.The improvements of photocatalytic activity of g-C_(3)N_(4) in the nanocomposite have been rationalized through the construction of direct Z-scheme heterojunction and suppression of electron-hole pair recombination efficiency.The enhanced photo-absorption of the nanocomposite can possibly be related to sub-bandgap absorption,which is associated to the midgap state originating from ligand-hole formation or defects in the structure.The photodegradation process is mediated through the formation of super oxide radical(O_(2))and hole(h^(+))as the main responsible species.
基金supported by the National Natural Science Foundation of China (No.41772264)the Applied Basic Research Programs of Science and Technology Foundation of Sichuan Province (No.18YYJC1745)the Research Fund of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (No.SKLGP2018Z001)。
文摘The degradation of pharmaceutical micropollutants is an intensifying environmental problem and synthesis of efficient photocatalysts for this purpose is one of the foremost challenges worldwide.Therefore,this study was conducted to develop novel plasmonic Ag/Ag2O/BiVO4 nanocomposite photocatalysts by simple precipitation and thermal decomposition methods,which could exhibit higher photocatalytic activity for mineralized pharmaceutical micropollutants.Among the different treatments,the best performance was observed for the Ag/Ag2O/BiVO4 nanocomposites (5 wt.%;10 min’s visible light irradiation)which exhibited 6.57 times higher photodegradation rate than the pure BiVO4.Further,the effects of different influencing factors on the photodegradation system of tetracycline hydrochloride (TC-HCl) were investigated and the feasibility for its practical application was explored through the specific light sources,water source and cycle experiments.The mechanistic study demonstrated that the photogenerated holes (h^+),superoxide radicals (·O2^-)and hydroxyl radicals (·OH) participated in TC-HCl removal process,which is different from the pure BiVO4 reaction system.Hence,the present work can provide a new approach for the formation of novel plasmonic photocatalysts with high photoactivity and can act as effective practical application for environmental remediation.