Catalytic oxidation of benzene with N_(2)O to phenol over the hierarchical and microporous Fe/ZSM-5-based catalysts in a continuous fixedbed reactor was investigated.The spent catalyst was in-situ regenerated by an ox...Catalytic oxidation of benzene with N_(2)O to phenol over the hierarchical and microporous Fe/ZSM-5-based catalysts in a continuous fixedbed reactor was investigated.The spent catalyst was in-situ regenerated by an oxidative treatment using N_(2)O and in total 10 reaction-regeneration cycles were performed.A 100% N_(2)O conversion,93.3% phenol selectivity,and high initial phenol formation rate of 16.49±0.06mmol_(phenol gcatalyst)^(-1)h^(-1)at time on stream(TOS) of 5 min,and a good phenol productivity of 147.06 mmol_(phenol gcatalyst)^(-1)during catalyst lifetime of 1800 min were obtained on a fresh hierarchical Fe/ZSM-5-Hi2.8 catalyst.With the reaction-regeneration cycle,N_(2)O conversion is fully recovered within TOS of 3 h,moreover,the phenol productivity was decreased ca.2.2±0.8% after each cycle,leading to a total phenol productivity of ca.0.44 ton_(pheol kg_(catalyst)^(-1)estimated for 300 cycles.Catalyst characterizations imply that the coke is rapidly deposited on catalyst surface in the initial TOS of 3 h(0.28 mgc_(gcatalyst)^(-1)min^(-1)) and gradually becomes graphitic during the TOS of 30 h with a slow formation rate of 0.06 mgc g_(catalyst)^(-1)min^(-1).Among others(e.g.,the decrease of textural property and acidity),the nearly complete coverage of the active Fe-O-Al sites by coke accounts for the main catalyst deactivation.Besides these reversible deactivation characteristics related to coking,the irreversible catalyst deactivation is also observed with the reaction-regeneration cycle.The latter is reflected by a further decreased amount of the active Fe-O-Al sites,which agglomerate on catalyst surface with the cycle,likely associated with the hard coke residue that is not completely removed by the regeneration.展开更多
To better understand the role of the-NH_(2)group in adsorption process of phenolic wastewaters,NH_(2)-functionalized MIL-53(Al)composites with activated carbon(NH_(2)-M(Al)@(B)AC)were prepared.The results showed that ...To better understand the role of the-NH_(2)group in adsorption process of phenolic wastewaters,NH_(2)-functionalized MIL-53(Al)composites with activated carbon(NH_(2)-M(Al)@(B)AC)were prepared.The results showed that the-NH_(2)group could increase the mesopore volume for composites,which promotes mass transfer and full utilization of active sites,because hierarchical mesopore structure makes the adsorbent easier to enter the internal adsorption sites.Furthermore,the introduction of the-NH_(2)group can improve the adsorption capacity,decrease the activation energy,and enhance the interaction between the adsorbent and p-nitrophenol,demonstrating that the-NH_(2)group plays a crucial role in the adsorption of p-nitrophenol.The density functional theory calculation results show that the H-bond interaction between the-NH_(2)group in the adsorbent and the-NO_(2)in the p-nitrophenol(adsorption energy of -35.5 kJ·mol^(-1)),and base-acid interaction between the primary-NH_(2)group in the adsorbent and the acidic-OH group in the p-nitrophenol(adsorption energy of -27.3 kJ·mol^(-1))are predominant mechanisms for adsorption in terms of the NH_(2)-functionalized adsorbent.Both NH_(2)-functionalized M(Al)@AC and M(Al)@BAC composites exhibited higher p-nitrophenol adsorption capacity than corresponding nonfunctionalized composites.Among the composites,the NH_(2)-M(Al)@BAC had the highest p-nitrophenol adsorption capacity of 474 mg·g^(-1).展开更多
TiO_(2) is a promising photocatalyst,but its practical use is restricted by its low catalytic efficiency caused by the large particle size and uneven size distribution,which arise from the limited contact area of the ...TiO_(2) is a promising photocatalyst,but its practical use is restricted by its low catalytic efficiency caused by the large particle size and uneven size distribution,which arise from the limited contact area of the liquid-liquid interface during synthesis.Impinging stream-rotating packed bed(IS-RPB)reactors,which are used for process intensification,overcome the mixing limitation of traditional stirred-tank reactors and provide a micromixing environment at the molecular scale for the two liquid phases,which can reduce the particle size and distribution range.Cu/N-TiO_(2) nanoparticles were prepared in an IS-RPB reactor by the one-step precipitation method using urea as the nitrogen source,titanyl sulfate as the titanium source,copper chloride as the copper source,and ammonium hydroxide as the precipitant.The particle size of the photocatalyst was about 11.40 nm with a narrow size distribution measured by scanning electron microscopy and transmission electron microscopy.X-ray photoelectron spectroscopy showed that N replaced some O and was uniformly dispersed in the TiO_(2) lattice as interstitial and substitutional N.Cu replaced some Ti and was present as Cu^(2+).The synergistic effects of these two elements formed a new impurity energy level and reduced the band gap energy of the TiO_(2) nanoparticles.The specific surface area of the Cu/N-TiO_(2) nanoparticles was 152.97 m^(2)/g.The effects of the main factors on the degradation rate were studied,and the removal efficiency reached 100%under the optimal operating conditions after 2 h ultraviolet irradiation.The electron paramagnetic resonance measurements showed that the superoxide radical played a main role in the degradation process,whereas the photogenerated holes and hydroxyl radicals had weak effects.展开更多
Objective:To investigate and compare the inhibitor)'properties)of free and bound phenolic extracts of clove bud against carbohydrate hydrolyzing enzymes(alpha-amylase&alphaglucosidase)and Fe^(2+)-induced lipid...Objective:To investigate and compare the inhibitor)'properties)of free and bound phenolic extracts of clove bud against carbohydrate hydrolyzing enzymes(alpha-amylase&alphaglucosidase)and Fe^(2+)-induced lipid peroxidation in rat pancreas in vitro.Methods:The free phenolics were extracted with 80%.(v/v)acetone,while bound phenolics were extracted from the alkaline and acid hydrolyzed residue with ethyl acetate.Then,the interaction of the extracts with alpha-amylase and alpha-glucosidase was subsequently assessed.Thereafter,the total phenolic contents and antioxidant activities of the extracts were determined.Results:The result revealed that both extracts inhibited alpha-amylase and alpha-glucosidase in a dose-dependent manner.However,the alpha-glucosidase inhibitory activity of the extracts were significantly(P<0.05)higher than their alpha-amylase inhibitory activity.The free phenolics(31.67 mg/g)and flavonoid(17.28 mg/g)contents were significantly(P<0.05)higher than bound phenolic(23.52 mg/g)and flavonoid(13.70 mg/g)contents.Both extracts also exhibited high antioxidant activities as typified by their high reducing power,LI diphenyl-2-picrylhydrazyl(DPPH)and 2,2-azinobis-3-ethylbenzo-thiazoline-6-sulfonate(ABTS)radical scavenging abilities,as well as inhibition of Fe^(2+)-induced lipid peroxidation in rat pancreas in vitro.Conclusions:This study provides a biochemical rationale by which clove elicits therapeutic effect on type 2 diabetes.展开更多
The catalyst of CUOx/Al2O3 was prepared by the dipping-sedimentation method using y-Al2O3 as a supporter. CuO and Cu2O were loaded on the surface of Al2O3, characterized by X-ray diffraction （XRD） and X-ray photoele...The catalyst of CUOx/Al2O3 was prepared by the dipping-sedimentation method using y-Al2O3 as a supporter. CuO and Cu2O were loaded on the surface of Al2O3, characterized by X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS）. In the presence of CuOx/Al2O3, the microwave-induced chlorine dioxide （ClO2） catalytic oxidation process was conducted for the treatment of synthetic wastewater containing 100 mg/L phenol. The factors influencing phenol removal were investigated and the results showed that microwave-induced C102-CuOx/ml203 process could effectively degrade contaminants in a short reaction time with a low oxidant dosage, extensive pH range. Under a given condition （ClO2 concentration 80 mg/L, microwave power 50 W, contact time 5 latin, catalyst dosage 50 g/L, pH 9）, phenol removal percentage approached 92.24%, corresponding to 79.13% of CODcr removal. The removal of phenol by microwave-induced ClO2-CuOx/Al2O3 catalytic oxidation process was a complicated non-homogeneous solid/water reaction, which fitted pseudo-first-order by kinetics. Compared with traditional ClO2 oxidation, ClO2 catalytic oxidation and microwave-induced ClO2 oxidation, microwave-induced ClO2 catalytic oxidation system could significantly enhance the degradation efficiency. It provides an effective technology for the removal of phenol wastewater.展开更多
Certain phenols and naphthols were nitrated regioselectively with Zn(NO)·6HO/TCT in acetonitrile as solvent at room temperature and short reaction time in good yields.The reaction condition was mild.TCT is a chea...Certain phenols and naphthols were nitrated regioselectively with Zn(NO)·6HO/TCT in acetonitrile as solvent at room temperature and short reaction time in good yields.The reaction condition was mild.TCT is a cheap and commercially available reagent.It performed as an acid catalyst in this transformation.展开更多
Sulfur doped anatase TiO2 nanoparticles （3 nm- 12 nm） were synthesized by the reaction of titanium tetrachloride, water and sulfuric acid with addition of 3 M NaOH at room temperature. The electro-optical and photoc...Sulfur doped anatase TiO2 nanoparticles （3 nm- 12 nm） were synthesized by the reaction of titanium tetrachloride, water and sulfuric acid with addition of 3 M NaOH at room temperature. The electro-optical and photocatalytic properties of the synthesized sulfur doped TiO2 nanoparticles were studied along with Degussa commercial TiO2 particles （24 nm）. The results show that band gap of TiO2 particles decreases from 3.31 to 3.25 eV and for that of commercial TiO2 to 3.2 eV when the particle sizes increased from 3 nm to 12 nm with increase in sulfur doping. The results of the photocatalytic activity under UV and sun radiation show maximum phenol conversion at the particle size of 4 nm at 4.80% S-doping. Similar results are obtained using UV energy for both phenol conversion and conversion of CO2＋H2O in which formation of methanol, ethanol and proponal is observed. Production of methanol is also achieved on samples with a particle size of 8 and 12 nm and sulfur doping of 4.80% and 5.26%. For TiO2 particle of 4 nm without S doping, the production of methanol, ethanol and proponal was lower as compared to the S-doped particles. This is attributed to the combined electronic effect and band gap change, S dopant, specific surface area and the light source used.展开更多
The title compound （E）-2-[（4-tert-butyl-5-（4-methoxybenzyl）thiazol-2-ylimino）methyl]phenol was synthesized by the reaction of 5-（4-methoxybenzyl）-4-tert- butylthiazol-2-amine with salicylaldehyde, and its crys...The title compound （E）-2-[（4-tert-butyl-5-（4-methoxybenzyl）thiazol-2-ylimino）methyl]phenol was synthesized by the reaction of 5-（4-methoxybenzyl）-4-tert- butylthiazol-2-amine with salicylaldehyde, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/c with a = 5.9362（8）, b = 11.5070（15）, c = 29.460（4）A, β= 97.326（3）°, V = 1995.9（5） A^3, Z = 4, F（000） = 808, C22H24N2O2S, Mr= 380.49, De= 1.266 g/cm^3, S = 1.031,μ = 0.181 mm^-1, the final R = 0.0474 and wR = 0.1441 for 4327 observed reflections （I 〉 2σ（I））. Intramolecular O-H…N hydrogen bond is observed in the crystal. The preliminary bioassay showed that the title compound exhibits 95% inhibition rate against Rhizoctonia solani at the test concentration of 500 mg/L.展开更多
Photodegradation ofpentachlorophenol （PCP） and p-nitrophenol （PNP） in soil was carried out in a designed rotary reactor, which can provide the soil particles with continually uniform irradiation, and on a series o...Photodegradation ofpentachlorophenol （PCP） and p-nitrophenol （PNP） in soil was carried out in a designed rotary reactor, which can provide the soil particles with continually uniform irradiation, and on a series of thin soil layers. TiO2, as a kind of environmental friendly photocatalyst, was introduced to the soil to enhance the processes. Compared with that on the soil layers, photodegradation of PCP at initial concentration of 60 mg/kg was improved dramatically in the rotary reactor no matter whether TiO2 was added, with an increase of 3.0 times in the apparent first-order rate constants. The addition of 1 wt% TiO2 furthered the improvement by 1.4 times. Without addition of TiO2, PNP （initial concentration of 60 mg/kg） photodegradation rate in the rotary reactor was similar to that on the soil layers. When 1 wt% additional TiO2 was added, PNP photodegradation was enhanced obviously, and the enhancement in the rotary reactor was 2 times of that on the soil layers, which may be attributed to the higher frequency of the contact between PNP on soil particles and the photocatalyst. The effect of soil pH and initial concentrations of the target compounds on the photodegradation in the rotary reactor was investigated. The order of the degradation rate at different soil pH was relative to the aggregation of soil particles during mixing in the rotary reactor. Photodegradation of PCP and PNP at different initial concentrations showed that addition of TiO2 to enhance the photodegradation was more suitable for contaminated soil with higher concentration of PCP, while was effective for contaminated soil at each PNP concentration tested in our study.展开更多
A novel high gravity multi-concentric cylinder electrodes-rotating bed(MCCE-RB) was developed for the electrocatalytic degradation of phenol wastewater in order to enhance the mass transfer with the self-made RuO_2-Ir...A novel high gravity multi-concentric cylinder electrodes-rotating bed(MCCE-RB) was developed for the electrocatalytic degradation of phenol wastewater in order to enhance the mass transfer with the self-made RuO_2-IrO_2-SnO_2/Ti anodes. The influences of electric current density, inlet liquid circulation flowrate, high gravity factor, sodium chloride concentration,and initial pH value on phenol degradation efficiency were investigated, with the optimal operating conditions determined. The results showed that under the optimal operating conditions covering a current density of 35 mA/cm^2, an inlet liquid circulation flowrate of 48 L/h, a high gravity factor of 20, a sodium chloride concentration of 8.5 g/L, an initial pH value of 6.5, a reaction time of 100 min, and an initial phenol concentration of 500 mg/L, the efficiency for removal of phenol reached 99.7%, which was improved by 10.4% as compared to that achieved in the normal gravity field. The tendency regarding the change in efficiency for removal of phenol, total organic carbon(TOC), and chemical oxygen demand(COD)over time was studied. The intermediates and degradation pathway of phenol were deduced by high performance liquid chromatography(HPLC).展开更多
To promote the photocatalytic performance TiO2 and enlarge its application in visible region, carbon doped TiO2 (C/TiO2) composites were synthesized by wet impregnation method using sucrose as a precursor and used for...To promote the photocatalytic performance TiO2 and enlarge its application in visible region, carbon doped TiO2 (C/TiO2) composites were synthesized by wet impregnation method using sucrose as a precursor and used for phenol photocatalytic reaction. The synthesized products were characterized by Nitrogen adsorption-desorption isotherms (BET), X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV-visible diffuse reflectance spectroscopy (UV-vis) techniques. The results showed that the obtained TiO2 was anatase phase in the C/TiO2 products, and its crystallite size was 11.7 nm, respectively. Carbon amount and calcined temperature of C/TiO2 can promote phenol removal. In this experiment, 5% carbon and 500 ℃ are the best choice for photocatalyst preparation. Under the UV light irradiation, 5%C/TiO2 (500 ℃, 2 h) exhibited the efficiency of 70.0% for phenol degradation within 150 min whereas TiO2 (500 ℃, 2 h) had 53.0% in the same duration of time. Also 5%C/TiO2 (500 ℃, 2 h) has higher photocatalytic performance under sunlight than pure TiO2. A combination of factors that include the smallest crystalline size, higher anatase percent, less band gap energy value and more oxygen vacant resulted in higher photocatalytic activities of 5%C/TiO2 (500 ℃, 2 h).展开更多
基金Financial support by the Specialized Research Fund for Doctoral Program of Higher Education,China (No.20120010110003)。
文摘Catalytic oxidation of benzene with N_(2)O to phenol over the hierarchical and microporous Fe/ZSM-5-based catalysts in a continuous fixedbed reactor was investigated.The spent catalyst was in-situ regenerated by an oxidative treatment using N_(2)O and in total 10 reaction-regeneration cycles were performed.A 100% N_(2)O conversion,93.3% phenol selectivity,and high initial phenol formation rate of 16.49±0.06mmol_(phenol gcatalyst)^(-1)h^(-1)at time on stream(TOS) of 5 min,and a good phenol productivity of 147.06 mmol_(phenol gcatalyst)^(-1)during catalyst lifetime of 1800 min were obtained on a fresh hierarchical Fe/ZSM-5-Hi2.8 catalyst.With the reaction-regeneration cycle,N_(2)O conversion is fully recovered within TOS of 3 h,moreover,the phenol productivity was decreased ca.2.2±0.8% after each cycle,leading to a total phenol productivity of ca.0.44 ton_(pheol kg_(catalyst)^(-1)estimated for 300 cycles.Catalyst characterizations imply that the coke is rapidly deposited on catalyst surface in the initial TOS of 3 h(0.28 mgc_(gcatalyst)^(-1)min^(-1)) and gradually becomes graphitic during the TOS of 30 h with a slow formation rate of 0.06 mgc g_(catalyst)^(-1)min^(-1).Among others(e.g.,the decrease of textural property and acidity),the nearly complete coverage of the active Fe-O-Al sites by coke accounts for the main catalyst deactivation.Besides these reversible deactivation characteristics related to coking,the irreversible catalyst deactivation is also observed with the reaction-regeneration cycle.The latter is reflected by a further decreased amount of the active Fe-O-Al sites,which agglomerate on catalyst surface with the cycle,likely associated with the hard coke residue that is not completely removed by the regeneration.
基金supported by the National Natural Science Foundation of China(22008134)。
文摘To better understand the role of the-NH_(2)group in adsorption process of phenolic wastewaters,NH_(2)-functionalized MIL-53(Al)composites with activated carbon(NH_(2)-M(Al)@(B)AC)were prepared.The results showed that the-NH_(2)group could increase the mesopore volume for composites,which promotes mass transfer and full utilization of active sites,because hierarchical mesopore structure makes the adsorbent easier to enter the internal adsorption sites.Furthermore,the introduction of the-NH_(2)group can improve the adsorption capacity,decrease the activation energy,and enhance the interaction between the adsorbent and p-nitrophenol,demonstrating that the-NH_(2)group plays a crucial role in the adsorption of p-nitrophenol.The density functional theory calculation results show that the H-bond interaction between the-NH_(2)group in the adsorbent and the-NO_(2)in the p-nitrophenol(adsorption energy of -35.5 kJ·mol^(-1)),and base-acid interaction between the primary-NH_(2)group in the adsorbent and the acidic-OH group in the p-nitrophenol(adsorption energy of -27.3 kJ·mol^(-1))are predominant mechanisms for adsorption in terms of the NH_(2)-functionalized adsorbent.Both NH_(2)-functionalized M(Al)@AC and M(Al)@BAC composites exhibited higher p-nitrophenol adsorption capacity than corresponding nonfunctionalized composites.Among the composites,the NH_(2)-M(Al)@BAC had the highest p-nitrophenol adsorption capacity of 474 mg·g^(-1).
基金supported by the Natural Science Foundation of Shanxi Province (201901D211222)the Natural Science Foundation of the Shanxi Province of China (201901D111173)the Scientific and Technological Innovation Programs of Higher Education Institution in Shanxi (2019L0515)
文摘TiO_(2) is a promising photocatalyst,but its practical use is restricted by its low catalytic efficiency caused by the large particle size and uneven size distribution,which arise from the limited contact area of the liquid-liquid interface during synthesis.Impinging stream-rotating packed bed(IS-RPB)reactors,which are used for process intensification,overcome the mixing limitation of traditional stirred-tank reactors and provide a micromixing environment at the molecular scale for the two liquid phases,which can reduce the particle size and distribution range.Cu/N-TiO_(2) nanoparticles were prepared in an IS-RPB reactor by the one-step precipitation method using urea as the nitrogen source,titanyl sulfate as the titanium source,copper chloride as the copper source,and ammonium hydroxide as the precipitant.The particle size of the photocatalyst was about 11.40 nm with a narrow size distribution measured by scanning electron microscopy and transmission electron microscopy.X-ray photoelectron spectroscopy showed that N replaced some O and was uniformly dispersed in the TiO_(2) lattice as interstitial and substitutional N.Cu replaced some Ti and was present as Cu^(2+).The synergistic effects of these two elements formed a new impurity energy level and reduced the band gap energy of the TiO_(2) nanoparticles.The specific surface area of the Cu/N-TiO_(2) nanoparticles was 152.97 m^(2)/g.The effects of the main factors on the degradation rate were studied,and the removal efficiency reached 100%under the optimal operating conditions after 2 h ultraviolet irradiation.The electron paramagnetic resonance measurements showed that the superoxide radical played a main role in the degradation process,whereas the photogenerated holes and hydroxyl radicals had weak effects.
文摘Objective:To investigate and compare the inhibitor)'properties)of free and bound phenolic extracts of clove bud against carbohydrate hydrolyzing enzymes(alpha-amylase&alphaglucosidase)and Fe^(2+)-induced lipid peroxidation in rat pancreas in vitro.Methods:The free phenolics were extracted with 80%.(v/v)acetone,while bound phenolics were extracted from the alkaline and acid hydrolyzed residue with ethyl acetate.Then,the interaction of the extracts with alpha-amylase and alpha-glucosidase was subsequently assessed.Thereafter,the total phenolic contents and antioxidant activities of the extracts were determined.Results:The result revealed that both extracts inhibited alpha-amylase and alpha-glucosidase in a dose-dependent manner.However,the alpha-glucosidase inhibitory activity of the extracts were significantly(P<0.05)higher than their alpha-amylase inhibitory activity.The free phenolics(31.67 mg/g)and flavonoid(17.28 mg/g)contents were significantly(P<0.05)higher than bound phenolic(23.52 mg/g)and flavonoid(13.70 mg/g)contents.Both extracts also exhibited high antioxidant activities as typified by their high reducing power,LI diphenyl-2-picrylhydrazyl(DPPH)and 2,2-azinobis-3-ethylbenzo-thiazoline-6-sulfonate(ABTS)radical scavenging abilities,as well as inhibition of Fe^(2+)-induced lipid peroxidation in rat pancreas in vitro.Conclusions:This study provides a biochemical rationale by which clove elicits therapeutic effect on type 2 diabetes.
基金Project supported by the National Nature Science Foundation of China(No.50678045).
文摘The catalyst of CUOx/Al2O3 was prepared by the dipping-sedimentation method using y-Al2O3 as a supporter. CuO and Cu2O were loaded on the surface of Al2O3, characterized by X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS）. In the presence of CuOx/Al2O3, the microwave-induced chlorine dioxide （ClO2） catalytic oxidation process was conducted for the treatment of synthetic wastewater containing 100 mg/L phenol. The factors influencing phenol removal were investigated and the results showed that microwave-induced C102-CuOx/ml203 process could effectively degrade contaminants in a short reaction time with a low oxidant dosage, extensive pH range. Under a given condition （ClO2 concentration 80 mg/L, microwave power 50 W, contact time 5 latin, catalyst dosage 50 g/L, pH 9）, phenol removal percentage approached 92.24%, corresponding to 79.13% of CODcr removal. The removal of phenol by microwave-induced ClO2-CuOx/Al2O3 catalytic oxidation process was a complicated non-homogeneous solid/water reaction, which fitted pseudo-first-order by kinetics. Compared with traditional ClO2 oxidation, ClO2 catalytic oxidation and microwave-induced ClO2 oxidation, microwave-induced ClO2 catalytic oxidation system could significantly enhance the degradation efficiency. It provides an effective technology for the removal of phenol wastewater.
文摘Certain phenols and naphthols were nitrated regioselectively with Zn(NO)·6HO/TCT in acetonitrile as solvent at room temperature and short reaction time in good yields.The reaction condition was mild.TCT is a cheap and commercially available reagent.It performed as an acid catalyst in this transformation.
文摘Sulfur doped anatase TiO2 nanoparticles （3 nm- 12 nm） were synthesized by the reaction of titanium tetrachloride, water and sulfuric acid with addition of 3 M NaOH at room temperature. The electro-optical and photocatalytic properties of the synthesized sulfur doped TiO2 nanoparticles were studied along with Degussa commercial TiO2 particles （24 nm）. The results show that band gap of TiO2 particles decreases from 3.31 to 3.25 eV and for that of commercial TiO2 to 3.2 eV when the particle sizes increased from 3 nm to 12 nm with increase in sulfur doping. The results of the photocatalytic activity under UV and sun radiation show maximum phenol conversion at the particle size of 4 nm at 4.80% S-doping. Similar results are obtained using UV energy for both phenol conversion and conversion of CO2＋H2O in which formation of methanol, ethanol and proponal is observed. Production of methanol is also achieved on samples with a particle size of 8 and 12 nm and sulfur doping of 4.80% and 5.26%. For TiO2 particle of 4 nm without S doping, the production of methanol, ethanol and proponal was lower as compared to the S-doped particles. This is attributed to the combined electronic effect and band gap change, S dopant, specific surface area and the light source used.
基金the National Project of Scientific and Technical Supporting Programs and Ministry of Science & Technology of China (No.2006BAE01A01-4)
文摘The title compound （E）-2-[（4-tert-butyl-5-（4-methoxybenzyl）thiazol-2-ylimino）methyl]phenol was synthesized by the reaction of 5-（4-methoxybenzyl）-4-tert- butylthiazol-2-amine with salicylaldehyde, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/c with a = 5.9362（8）, b = 11.5070（15）, c = 29.460（4）A, β= 97.326（3）°, V = 1995.9（5） A^3, Z = 4, F（000） = 808, C22H24N2O2S, Mr= 380.49, De= 1.266 g/cm^3, S = 1.031,μ = 0.181 mm^-1, the final R = 0.0474 and wR = 0.1441 for 4327 observed reflections （I 〉 2σ（I））. Intramolecular O-H…N hydrogen bond is observed in the crystal. The preliminary bioassay showed that the title compound exhibits 95% inhibition rate against Rhizoctonia solani at the test concentration of 500 mg/L.
基金The National Basic Research Program of China (No. 2004CB418504 2003CB415006)
文摘Photodegradation ofpentachlorophenol （PCP） and p-nitrophenol （PNP） in soil was carried out in a designed rotary reactor, which can provide the soil particles with continually uniform irradiation, and on a series of thin soil layers. TiO2, as a kind of environmental friendly photocatalyst, was introduced to the soil to enhance the processes. Compared with that on the soil layers, photodegradation of PCP at initial concentration of 60 mg/kg was improved dramatically in the rotary reactor no matter whether TiO2 was added, with an increase of 3.0 times in the apparent first-order rate constants. The addition of 1 wt% TiO2 furthered the improvement by 1.4 times. Without addition of TiO2, PNP （initial concentration of 60 mg/kg） photodegradation rate in the rotary reactor was similar to that on the soil layers. When 1 wt% additional TiO2 was added, PNP photodegradation was enhanced obviously, and the enhancement in the rotary reactor was 2 times of that on the soil layers, which may be attributed to the higher frequency of the contact between PNP on soil particles and the photocatalyst. The effect of soil pH and initial concentrations of the target compounds on the photodegradation in the rotary reactor was investigated. The order of the degradation rate at different soil pH was relative to the aggregation of soil particles during mixing in the rotary reactor. Photodegradation of PCP and PNP at different initial concentrations showed that addition of TiO2 to enhance the photodegradation was more suitable for contaminated soil with higher concentration of PCP, while was effective for contaminated soil at each PNP concentration tested in our study.
基金financially supported by the Nature Science Foundation of China (Grant No.U1610106)the Nature Science Foundation of China (Grant No.21703208)
文摘A novel high gravity multi-concentric cylinder electrodes-rotating bed(MCCE-RB) was developed for the electrocatalytic degradation of phenol wastewater in order to enhance the mass transfer with the self-made RuO_2-IrO_2-SnO_2/Ti anodes. The influences of electric current density, inlet liquid circulation flowrate, high gravity factor, sodium chloride concentration,and initial pH value on phenol degradation efficiency were investigated, with the optimal operating conditions determined. The results showed that under the optimal operating conditions covering a current density of 35 mA/cm^2, an inlet liquid circulation flowrate of 48 L/h, a high gravity factor of 20, a sodium chloride concentration of 8.5 g/L, an initial pH value of 6.5, a reaction time of 100 min, and an initial phenol concentration of 500 mg/L, the efficiency for removal of phenol reached 99.7%, which was improved by 10.4% as compared to that achieved in the normal gravity field. The tendency regarding the change in efficiency for removal of phenol, total organic carbon(TOC), and chemical oxygen demand(COD)over time was studied. The intermediates and degradation pathway of phenol were deduced by high performance liquid chromatography(HPLC).
基金Funded by Yunnan Provincial Agricultural Joint Project (No.2018FG001-051)Yunnan Provincial Department of Education Research Fund (No. 2020Y0414)
文摘To promote the photocatalytic performance TiO2 and enlarge its application in visible region, carbon doped TiO2 (C/TiO2) composites were synthesized by wet impregnation method using sucrose as a precursor and used for phenol photocatalytic reaction. The synthesized products were characterized by Nitrogen adsorption-desorption isotherms (BET), X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV-visible diffuse reflectance spectroscopy (UV-vis) techniques. The results showed that the obtained TiO2 was anatase phase in the C/TiO2 products, and its crystallite size was 11.7 nm, respectively. Carbon amount and calcined temperature of C/TiO2 can promote phenol removal. In this experiment, 5% carbon and 500 ℃ are the best choice for photocatalyst preparation. Under the UV light irradiation, 5%C/TiO2 (500 ℃, 2 h) exhibited the efficiency of 70.0% for phenol degradation within 150 min whereas TiO2 (500 ℃, 2 h) had 53.0% in the same duration of time. Also 5%C/TiO2 (500 ℃, 2 h) has higher photocatalytic performance under sunlight than pure TiO2. A combination of factors that include the smallest crystalline size, higher anatase percent, less band gap energy value and more oxygen vacant resulted in higher photocatalytic activities of 5%C/TiO2 (500 ℃, 2 h).
