Phosphotungstic acid ionic liquid for efficient photocatalytic desulfurization:Synthesis,application and mechanism

An efficient mass transfer process is a critical factor for regulating catalytic activity in a photocatalytic desulfurization system.Herein,a phosphotungstic acid(HPW)active center is successfully composited with a quaternary ammonium phosphotungstate-based hexadecyltrimethylammonium chloride ionic liquid(CTAC-HPW)by the ion exchange method for the photocatalytic oxidative desulfurization of dibenzothiophene sulfide.The keggin structure of HPW and highly mass transfer performance of organic cations synergistically enhanced the photocatalytic activity towards the effective convertion of dibenzothiophene(DBT)with the excitation of visible light.The deep desulfurization(<10 mg·kg^(-1))is attained within 30 min,and well stability is demonstrated within 25 cycles.Moreover,the CTAC-HPW photocatalyst projects well selectivity to interference from coexisting compounds such as olefins and aromatic hydrocarbons and universality of dibenzothiophenes,for example,4-methyldibenzothiophene(4-MDBT)and 4,6-dimethyldibenzothiophene(4,6-DMDBT).Ultimately,a possible photocatalytic desulfurization mechanism is proposed according to the Gaschromatography-mass spectrometry(GC-MS),proving that the final product is the corresponding sulfone.The trapping experiment and electron spin resonance(ESR)analysis confirmed that h^(+)and,COOH played critical roles in the oxidation process.The work offers a practicable strategy for efficiently converting DBT to DBTO_(2) with added value.

3D-printing of integrated spheres as a superior support of phosphotungstic acid for deep oxidative desulfurization of fuel

Construction of catalysts with integral structure for oxidative reaction process is an essential promotion to catalysts in industrial application.In this work,a 3D printing method was employed to prepare 3D printed spheres(3D-PSs),followed by carbonization to form 3D carbon spheres(3D-CSs).Then,a 3D-CSs supported phosphotungstic acid(HPW/3D-CSs)was prepared for deep oxidative desulfurization.Compared with traditional powder catalysts,the as-prepared catalyst is easy to be operated and separated from oil products.The supported catalyst possesses excellent catalytic performance and the removal of DBT,4-MDBT and 4,6-DMDBT in fuel oil,reaching^100%of sulfur removal.The effects of various experimental parameters on desulfurization efficiency were considered to optimize reaction conditions.Moreover,the catalyst shows excellent thermal and chemical stability,with no obvious decrease in desulfurization activity after 5 cycles.GC–MS analysis indicates DBT sulfone was the solely oxidized product of DBT.

Amorphous TiO_2-supported Keggin-type ionic liquid catalyst catalytic oxidation of dibenzothiophene in diesel

Supported ionic liquid(IL) catalysts [Cmim]PMoO/Am TiO(amorphous TiO) were synthesized through a one-step method for extraction coupled catalytic oxidative desulfurization(ECODS) system. Characterizations such as FTIR, DRS,wide-angle XRD, Nadsorption–desorption and XPS were applied to analyze the morphology and Keggin structure of the catalysts. In ECODS with hydrogen peroxide as the oxidant, it was found that ILs with longer alkyl chains in the cationic moiety had a better effect on the removal of dibenzothiophene. The desulfurization could reach 100% under optimal conditions, and GC–MS analysis was employed to detect the oxidized product after the reaction. Factors affecting the desulfurization efficiencies were discussed, and a possible mechanism was proposed. In addition, cyclic experiments were also conducted to investigate the recyclability of the supported catalyst. The catalytic activity of [Cmim]PMoO/Am TiOonly dropped from 100% to 92.9% after ten cycles, demonstrating the good recycling performance of the catalyst and its potential industrial application.

One-pot in-situ synthesis of coralloid supported VO_(2)catalyst for intensified aerobic oxidative desulfurization

A coralloid 3D g-C_(3)N_(4)supported VO_(2)catalyst was successfully synthesized in-situ by one-pot method,avoiding the agglomeration of VO_(2)during the reaction.The morphological and compositional information of the supported catalyst were investigated detailedly.30%VO_(2)/3D g-C_(3)N_(4)revealed excellent catalytic activity in aerobic oxidative desulfurization,the oxidative of dibenzothiophene(DBT),4-methyldibenzothiophene(4-MDBT)and 4,6-dimethyldibenzothiophene(4,6-DMDBT)reached 98.6%,99%and 99.4%,respectively,under the same mild conditions.The recycling performance and the mechanism on the oxidative of DBT were studied as well.

Photocatalytic oxidative of Keggin-type polyoxometalate ionic liquid for enhanced extractive desulfurization in binary deep eutectic solvents

A series of novel binary deep eutectic solvents(DESs)composed of choline chloride(ChCl)and formic acid(HCOOH)with different molar ratios have been successfully synthesized and applied in extractive desulfurization(EDS).Keggin-type polyoxometallate ionic liquid[TTPh]_(3)PW_(12)O_(40) was prepared and used as catalyst to enhance the EDS capacity by means of photocatalytic oxidative process.Both of the DESs and[TTPh]_(3)PW_(12)O_(40) ionic liquid catalyst were characterized in detail by Fourier transform infrared spectroscopy spectra(FT-IR),elemental analysis,and X-ray photoelectron spectroscopy(XPS).It was found that the molar ratios of Ch Cl:HCOOH had a major impact on desulfurization performance,and the optimal desulfurization capacity 96.5%was obtained by ChCl/5 HCOOH.Besides dibenzothiophene(DBT),the desulfurization efficiencies of 4-methylbenzothiophene(4-MDBT)and 4,6-dimethyldibenzothiophene(4,6-DMDBT),two kinds of DBT derivatives,were also investigated under the same experimental conditions.Moreover,the free radical scavenging experiments manifested that superoxide radical(·O_(2)^(-)) and hole(h^(+)) played important roles in the desulfurization system.After further analysis of the oxidation products by gas chromatography-mass spectrometry(GC–MS),the possible reaction mechanism was proposed.Thus,photocatalytic oxidative has been proved to be one of the efficient approaches for enhancing the extractive desulfurization performance in DES.

Hydrochloric acid‐mediated synthesis of ZnFe_(2)O_(4) small particle decorated one‐dimensional Perylene Diimide S‐scheme heterojunction with excellent photocatalytic ability

The recyclable and stable ZnFe_(2)O_(4) small particle decorated one‐dimensional perylene diimide(PDI)S‐scheme heterojunction(1D PDI/ZnFe_(2)O_(4))is prepared by the hydrochloric acid‐mediated(HCl‐mediated)strategy,interestingly,the morphology of the 1D PDI/ZnFe_(2)O_(4) can also be effectively regulated by HCl‐mediated process,the existence of HCl can regulate PDI into a uniform rod structure,while the co‐existence of HCl and PDI can limit ZnFe_(2)O_(4) to become the uniform small particles.More importantly,based on the 1D rod structure of PDI and the small size effect of ZnFe_(2)O_(4),carriers can migrate to the surface more easily,which can improve the photocatalytic activity.Meanwhile,due to the appropriate energy level structure,the S‐scheme heterojunction structure is formed between PDI and ZnFe_(2)O_(4),which eliminates meaningless photo‐generated charge carriers through recombination and introduces strong redox to further enhance the photodegradation effect,thereby,1D PDI/ZnFe_(2)O_(4) exhibits excellent photocatalytic ability,under the visible light irradiation,the degradation rate of tetracycline(TC)with 1D PDI/ZnFe_(2)O_(4)(66.67%)is 9.18 times that with PDI(7.26%)and 9.73 times that with ZnFe_(2)O_(4)(6.85%).This work proposes new ideas for the assembly of magnetic organic‐inorganic S‐scheme heterojunction photocatalysts.

Visible-light-driven photocatalysis degradation of antibiotic pollutants by La-doped CeO_(2) nanorods:synergy of La doping and oxygen vacancy

Elemental doping is an effective strategy to enhance photocatalytic activity and extend the light absorption range of single-component photocatalysts.In this work,a series of La-doped CeO_(2) nanorods(La-CeO_(2)-x) with La content of 1 wt%-15 wt% are synthesized by a simple hydrothermal method and further used as photocatalyst for sulfamerazine(SMR) degradation.The prepared La-CeO_(2)-x nanorods exhibit a great improvement in electron-hole pair migration and visible-light response due to the synergistic effect of abundant oxygen vacancies and heterogeneous elements(La).Consequently,La-CeO_(2)-x exhibited excellent visible-light photocatalytic performances and chemical stability for SMR degradation,the La-CeO_(2)-5 sample achieved the highest SMR degradation rate of 81%,which was 3.4 times higher than that of the original CeO_(2).Furthermore,three possible degradation pathways of SMR in La-CeO_(2) photocatalytic reactions were proposed by liquid chromatography-mass spectrometry technique.Finally,density functional theory calculations were carried out to provide an in-depth understanding of the structure-performance relationships.Considering its excellent properties and better photocatalytic performance,this study demonstrates that La doping in CeO_(2) is an effective way to increase oxygen vacancy and improve the photochemical properties of photocatalysts.

Comparative analysis of CO_(2)emissions and economic performance in the United States and China:Navigating sustainable development in the climate change era

Economic growth has brought a global climate change into the spotlight,and CO_(2)emissions demonstrate significant challenges in reducing environmental shifts worldwide.Globally,the United States and China contribute the largest amount of CO_(2)emissions.The purpose of this study is to examine the relationship between different types of CO_(2)emissions and economic growth by using a modeling approach.We analyze total CO_(2)emissions,coal CO_(2)emissions,oil CO_(2)emissions,the global share of coal CO_(2)emissions,the global share of oil CO_(2)emissions,and economic growth.This study provides unique insights into how to simultaneously reduce CO_(2)emissions and sustain economic growth.A bootstrap autoregressive distributed lag(BARDL)simulation method is utilized to examine the long-and short-run effects of predictors on CO_(2)emissions.Coal CO_(2)emissions are found to have a significant positive effect on economic growth in the short run but a negative impact on economic growth over the long run in the United States.The United States needs to implement stronger measures to balance coal CO_(2)emissions with economic growth for sustainable development.In contrast,oil CO_(2)emissions have positive effect for China in both the long run and short run.Thus,China can continue to reduce CO_(2)emissions from oil while maintaining positive economic growth.The China’s policies promoting cleaner energy alternatives can be adapted and implemented to maintain a balance between economic growth and carbon reduction.The study has valuable insights for policymakers seeking to balance economic growth with carbon reduction strategies.It emphasizes the need to better understand the complex relationship between CO_(2)emissions and economic growth.

Pt nanoparticles encapsulated on V_(2)O_(5)nanosheets carriers as efficient catalysts for promoted aerobic oxidative desulfurization performance

Platinum group metals(PGMs)usually exhibit promising aerobic catalytic abilities,providing a green and feasible oxidative desulfurization method.However,often,the PGM nanoparticles(NPs)get leached,and the catalysts are deactivated.In this work,Pt NPs with particle sizes of approximately 4–5 nm were encapsulated effectively and uniformly on the surface of vanadium pentoxide(V2O5)nanosheets(with thicknesses of approximately six atomic layers)through strong metal-support interactions.The synthesized catalysts promote catalytic aerobic oxidation reactions,realizing deep desulfurization(99.1%,<5μg g^(–1))under atmospheric pressure and 110℃reaction temperature.Remarkable degrees of sulfur removal could be achieved for oils with different initial S-concentrations and substrates.Additionally,the as-prepared catalysts could be recycled for reuse at least seven times.

In-suit fabricating an efficient electronic transport channels via S-scheme polyaniline/Cd_(0.5)Zn_(0.5)S heterojunction for rapid removal of tetracycline hydrochloride and hydrogen production

The development of highly efficient catalyst is the key for photocatalytic technology to deal with water pollution and energy problems.In this work,the S-scheme polyaniline/Cd_(0.5)Zn_(0.5)S(PANI/CZS)nanocomposites were elaborately prepared for the first time by in-situ oxidation polymerization.Compared to pure PANI and Cd_(0.5)Zn_(0.5)S,this PANI/CZS hybrid displayed outstanding photocatalytic performance in removing tetracycline hydrochloride(TCH)and hydrogen evolution under light irradiation.Among them,15 PANI/CZS sample could achieve 84.9%TCH degradation efficiency within 25 min,and the degradation rate(0.06931 min−1)was 5.13 times than that of Cd_(0.5)Zn_(0.5)S(0.0135 min^(−1)).The optimal photocatalytic H_(2) evolution rate of 30 PANI/CZS sample was 15.57 mmol g^(-1) h^(-1),which was twice that of Cd_(0.5)Zn_(0.5)S(7.34 mmol g^(-1) h^(-1)).These results were mainly attributed to the efficient electronic transport channels provided by S-scheme heterojunction structure.The density functional theory(DFT)calculation proved that the difference of work function resulted in band bending and forming built-in electric field on the contact interface of PANI/CZS,which facilitated the migration and separation of interfacial photogener-ated charge carriers for the strengthened photocatalytic performance.Further,the degradation interme-diate products and pathways of TCH were also put forwarded in depth based on MS experiment.At last,the S-scheme electron transport model and the photocatalytic reaction mechanism in PANI/CZS hetero-junction structure were studied.This work provided an innovative vision in developing high-performance S-scheme heterojunction multifunctional photocatalysts.

Efficient aerobic oxidative desulfurization via three-dimensional ordered macroporous tungsten-titanium oxides

A series of three-dimensional ordered macroporous(3 DOM)W-TiO_(2)catalysts have been prepared through a facile colloidal crystal template method.The prepared materials characterized in detail exhibited enhanced catalytic activity in aerobic oxidative desulfurization process.The experimental results indicated that the as-prepared materials possessed excellent 3 DOM structure,which is beneficial for the catalytic activity.The sample 3 DOM W-TiO_(2)-20 exhibited the highest activity in ODS process,and the sulfur removal can reach 98%in 6 h.Furthermore,the oxidative product was also analyzed in the reaction process.

Interactions between invasive plants and heavy metal stresses:a review

Global changes have altered the distribution pattern of the plant communities,including invasive species.Anthropogenic contamination may reduce native plant resistance to the invasive species.Thus,the focus of the current review is on the contaminant biogeochemical behavior among native plants,invasive species and the soil within the plant-soil ecosystem to improve our understanding of the interactions between invasive plants and environmental stressors.Our studies together with synthesis of the literature showed that(i)the impacts of invasive species on environmental stress were heterogeneous,(ii)the size of the impact was variable and(iii)the influence types were multidirectional even within the same impact type.However,invasive plants showed self-protective mechanisms when exposed to heavy metals(HMs)and provided either positive or negative influence on the bioavailability and toxicity of HMs.On the other hand,HMs may favor plant invasion due to the widespread higher tolerance of invasive plants to HMs together with the‘escape behavior’of native plants when exposed to toxic HM pollution.However,there has been no consensus on whether elemental compositions of invasive plants are different from the natives in the polluted regions.A quantitative research comparing plant,litter and soil contaminant contents between native plants and the invaders in a global context is an indispensable research focus in the future.

Utilization of porous liquids for catalytic conversion

Porous liquids,an emerging type of flowing liquid materials,are composed of porous solids and polymer chains/sterically hindered sol-vents,combining the advantages of porous solids'permanent porosity and liquid's fluidity.Therefore,porous liquids have shown enormous potentials in many applications.However,these applications are limited to gas adsorption[1],transport[2]and separation[3],which is unfa-vorable for the development of porous liquids.Therefore,expanding the application of porous liquids in other fields is quite meaningful.