In the paper,we report a highly robust and porous bimetallic Ti-MOF(designated Mg_(2)Ti-ABTC)by utiliz-ing a trinuclear[Mg_(2)TiO(COO)_(6)]cluster and a tetradentate H_(4)ABTC(3,3′,5,5′-azobenzene tetracarboxylic ac...In the paper,we report a highly robust and porous bimetallic Ti-MOF(designated Mg_(2)Ti-ABTC)by utiliz-ing a trinuclear[Mg_(2)TiO(COO)_(6)]cluster and a tetradentate H_(4)ABTC(3,3′,5,5′-azobenzene tetracarboxylic acid)ligand.Mg_(2)Ti-ABTC exhibited permanent porosity for N_(2),CO_(2),CH_(4),C_(2)H_(2),C_(2)H_(4),and C_(2)H_(6)gas adsorption.Further-more,Mg_(2)Ti-ABTC exhibited outstanding photocatalytic activity in the oxidation of aromatic sulfides to the corre-sponding sulfoxides under ambient air conditions.Mechanism studies reveal that photoinduced holes(h^(+)),the super-oxide radical(·O_(2)^(-)),and singlet oxygen(^(1)O_(2))are pivotal species involved in the photocatalytic oxidation reaction.展开更多
This research aims to explore the decoration of TiO_(2) substrates with silver nanoparticles as a means of enhancing the photocatalytic oxidation of organic compounds.The results show that decorated TiO_(2) substrates...This research aims to explore the decoration of TiO_(2) substrates with silver nanoparticles as a means of enhancing the photocatalytic oxidation of organic compounds.The results show that decorated TiO_(2) substrates exhibit significantly higher photocatalytic activity in sunlight than undecorated substrates.Morphological analysis is performed,followed by optical and structural characterizations.Scanning electron microscopy analysis of the TiO_(2) reveals many nanotubular structures with particle sizes of∼134.4,148.8,and 132.7 nm at random locations.TiO_(2) is also found to have an absorbance range of 397.6 nm,from which it is known that the photocatalyst reacts in the presence of an ultraviolet source.From the Miller indices of the x-ray diffraction peaks,the preferred crystal orientation is found to be associated with a face-centered cubic structure with a crystallite size of 3.76 nm.Using these promising results,photocatalytic analysis is performed,revealing good degradation characteristics.This investigation reveals that TiO_(2) substrates coated with Ag nanoparticles possess significant potential for application in the photocatalytic oxidation of methylene blue dye,which is a crucial step toward establishing a cleaner environment.展开更多
For the efficient harnessing of solar energy and mitigation of environmental pollution,the develop-ment and application of semiconductor photocatalysis technology is paramount.Herein,a novel SubPc-Br/CdS supramolecula...For the efficient harnessing of solar energy and mitigation of environmental pollution,the develop-ment and application of semiconductor photocatalysis technology is paramount.Herein,a novel SubPc-Br/CdS supramolecular array with an S-scheme heterojunction was synthesized through the intermolecu-larπ-stacked self-assembly of subphthalocyanine(SubPc-Br)and nanometer cadmium sulfide(CdS).This self-assembly system features a highly structured architecture and excellent stability.Experiments and ground-state differential charge calculations demonstrate that SubPc-Br and CdS form a built-in electric field during the self-assembly process,a critical factor in promoting the dissociation of electrons and holes.Additionally,this study utilized time-dependent density functional theory(TDDFT)to simulate the dynamic adsorption behavior of excited oxygen molecules on the SubPc-Br/CdS interface for the first time.The analysis of molecular charge differential density under different excited states proved that the addi-tion of SubPc-Br molecules not only improves the photocorrosion resistance of CdS in an O2 adsorption environment but also enhances the production of advanced reactive oxygen species under the synergistic action of h+and·O2-.When subjected to visible light,the degradation efficiency of minocycline(MC)achieved 96.8%within 60 min and maintained 80.3%after 5 cycles.In summary,this study highlights the feasibility of creating advanced S-scheme heterojunction photocatalysts through the strategic incor-poration of organic supramolecules with semiconductor catalysts.展开更多
In order to remove nitric oxides （NO） from flue gas, experimental studies on the photocatalytic oxidation （PCO） of NO are carried out in an efficient laboratory-scale reactor. Nano-sized TiO2 particles loading on ...In order to remove nitric oxides （NO） from flue gas, experimental studies on the photocatalytic oxidation （PCO） of NO are carried out in an efficient laboratory-scale reactor. Nano-sized TiO2 particles loading on quartz sand are prepared and used as the photocatalyst. Effects of several key operating parameters on NO conversion are investigated, including operating temperature, NO inlet concentration, oxygen percentage, relative humidity and residence time. The results illustrate that the NO inlet concentration, the oxygen percentage and the relative humidity play an important role in the oxidation of NO. A lower NO inlet concentration and a higher oxygen percentage result in a higher NO conversion efficiency. When the relative humidity is 8%, the maximum value of NO conversion efficiency is achieved. In addition, the operating temperature and the residence time have a little effect on the conversion efficiency of NO.展开更多
Development of clean desulfurization process that combines both efficient and environmentally friendly remains a significant challenge for diesel production.The photocatalytic oxidation desulfurization technology is r...Development of clean desulfurization process that combines both efficient and environmentally friendly remains a significant challenge for diesel production.The photocatalytic oxidation desulfurization technology is regarded as a promising process depending on the superior electron transfer and visible light utilization of photocatalyst.Herein,the nonstoichiometry MoO_(3-x)with outstanding photoresponse ability is prepared and modified by imidazole-based ionic liquid[C_(12)mim]Cl to upgrade electronic structure.The interface H-bonding between MoO_(3-x)and[C_(12)mim]Cl regard as electronic transfer channel and the recombination of e^(-)-h^(+)pairs is effectively inhibited with the modification of[C_(12)mim]Cl.Deep desulfurization rate of 96.6%can be reached within 60 min and the MoO_(3-x)/[C_(12)mim]Cl(MoC_(12))photocatalyst demonstrated outstanding cyclic stability within 7 cycles in an extraction coupled photocatalytic oxidation desulfurization(ECPODS)system.The study provides a new perspective on enhancing photocatalytic desulfurization through defect engineering and surface modification.展开更多
The simultaneous accumulation of photo-holes and the specific activation of substrates present a significant challenge in photo-oxidation.Herein,we propose a dual-channel collaborative catalytic platform based on holl...The simultaneous accumulation of photo-holes and the specific activation of substrates present a significant challenge in photo-oxidation.Herein,we propose a dual-channel collaborative catalytic platform based on hollow TiO_(2) microspheres,using Cu single-atom(SA)catalysts and a composite polymer chain,to create separating pathways for unidirectional photogenerated electron/hole extraction.Ferrocene-functionalized graphene quantum dots are incorporated within the polymer chain for driving benzylamine(BA)oxidation.Quasi in situ transient photovoltage and femtosecond transient absorption tests reveal that leveraging the ultrafast charge separation capability of Cu SAs(0.44 ps)not only accelerates hole transport kinetics but also induces requisite Lewis acidity for the adsorption and activation of BA.In an air atmosphere,the rate of imine production reaches 4.81 mmol g^(−1) h^(−1)(selectivity of 98%).This study demonstrates the rational design of an SA/polymer chain dual-driven catalytic platform for optimizing kinetics and precisely controlling photocatalytic transformations in organic chemistry.展开更多
A carbon‐doped TiO2/fly ash support(C‐TiO2/FAS)composite photocatalyst was successfully synthesized through sol impregnation and subsequent carbonization.The carbon dopants were derived from the organic species gene...A carbon‐doped TiO2/fly ash support(C‐TiO2/FAS)composite photocatalyst was successfully synthesized through sol impregnation and subsequent carbonization.The carbon dopants were derived from the organic species generated during the synthesis of the C‐TiO2/FAS composite.A series of analytical techniques,such as scanning electron microscopy(SEM),attenuated total reflection‐Fourier transform infrared(ATR‐FTIR)spectroscopy,X‐ray photoelectron spectroscopy(XPS),and ultraviolet‐visible diffuse reflectance spectroscopy(UV‐Vis DRS),were used to characterize the properties of the prepared samples.The results indicated that C‐TiO2 was successfully coated on the FAS surface.Coupling between C‐TiO2 and FAS resulted in the formation of Si–O–C and Al–O–Ti bonds at their interface.The formation of Si–O–C and Al–O–Ti bonds gave rise to a positive shift of the valence band edge of C‐TiO2 and enhanced its oxidation capability of photogenerated holes as well as photodegradation efficiency of methyl orange.Moreover,the C‐TiO2/FAS photocatalyst exhibited favorable reusability and separability.This work may provide a new route for tuning the electronic band structure of TiO2.展开更多
A series of nanosized ion-doped TiO2 catalysts with different ion content （between 0.1 at.% and 1.0 at.%） have been prepared by wet impregnation method and investigated with respect to their behavior for UV photocat...A series of nanosized ion-doped TiO2 catalysts with different ion content （between 0.1 at.% and 1.0 at.%） have been prepared by wet impregnation method and investigated with respect to their behavior for UV photocatalytic oxidation of nitric oxide. The catalytic activity was correlated with structural, electronic and surface examinations of the catalysts using X-ray diffraction analysis （XRD）, ultraviolet-visible （UV-Vis） absorption spectroscopy, transmission electron microscopy （TEM）, energy disperse spectrometer （EDS） and high resolution-transmission electron microscopy （HR-TEM） techniques. An enhancement of the photocatalytic activity was observed for Zn2＋ doping catalyst ranged from 0.1 at.% to 1.0 at.% which was attributed to the lengthened lifetime of electrons and holes. The improvement in photocatalytic activity could be also observed with the low doping concentration of Cr^3＋ （0.1 at.%）. However, the doping of Fe^3＋, Mo^6＋, Mn^2＋ and the high doping concentration of Cr^3＋ had no contribution to photocatalytic activity of nitric oxide.展开更多
In this study, a hybrid process using non‐thermal plasma (NTP) and photocatalytic oxidation (PCO) was adopted for the degradation of gas‐phase toluene using TiO2 as the photocatalyst. To discover the synergetic effe...In this study, a hybrid process using non‐thermal plasma (NTP) and photocatalytic oxidation (PCO) was adopted for the degradation of gas‐phase toluene using TiO2 as the photocatalyst. To discover the synergetic effect between NTP and PCO, the performances of both sole (O3, UV, NTP, and PCO) and combined (O3 + TiO2, O3 + UV, NTP + UV, O3 + PCO, and NTP + PCO) processes were investigated from different perspectives, such as the toluene removal efficiency, selectivity of COx, mineralization rate, ozone utilization, and the generation of by‐products. The toluene removal efficiency of the combined NTP + PCO process was 80.2%, which was much higher than that of a sole degradation process such as NTP (18.8%) and PCO (13.4%). The selectivity of CO2 and the ozone utilization efficiency also significantly improved. The amount of by‐products in the gas phase and the carbon‐ based intermediates adsorbed on the catalyst surface dramatically reduced. The improvement in the overall performances of the combined NTP + PCO process was mainly ascribed to the efficient utilization of ozone in the photocatalytic oxidation, and the ozone further acting as an electron acceptor and scavenger, generating more hydroxyl radicals and reducing the recombination of electron‐ hole pairs.展开更多
Novel Bi_(2)MoO_(6) nanocrystals with tunable oxygen vacancies have been developed via a facile low-cost approach with the assistance of a glyoxal reductant under solvothermal conditions.With the introduction of oxyge...Novel Bi_(2)MoO_(6) nanocrystals with tunable oxygen vacancies have been developed via a facile low-cost approach with the assistance of a glyoxal reductant under solvothermal conditions.With the introduction of oxygen vacancies,the optical absorption of Bi_(2)MoO_(6) is extended and its bandgap narrowed.Oxygen vacancies not only lead to the appearance of a defect band level in the forbidden band but can also result in a minor up-shift of the valence band maximum,promoting the mobility of photogenerated holes.Moreover,oxygen vacancies can act as electron acceptors,temporarily capturing electrons excited by light and reducing the recombination of electrons and holes.At the same time,oxygen vacancies help to capture oxygen,which reacts with the captured photogenerated electrons to generate more superoxide radicals(·O_(2)-)to participate in the reaction,thereby significantly promoting the redox performance of the photocatalyst.From Bi_(2)MoO_(6) containing these oxygen vacancies(OVBMO),excellent photocatalytic performance has been obtained for the oxidation of 1,2,3,4-tetrahydroquinoline to produce quinoline and cause antibiotic degradation.The reaction mechanism of the oxidation of 1,2,3,4-tetrahydroquinoline to quinoline over the OVBMO materials is elucidated in terms of heterogeneous Catal.via a radical pathway.展开更多
A series of TiO 2-XSiO 2[X denotes the molar fraction(%) of silica in the mixed oxides] with different \{n(Ti)\}/n(Si) ratios was prepared with ammonia water as a hydrolysis catalyst. The photocatalysts prepared wer...A series of TiO 2-XSiO 2[X denotes the molar fraction(%) of silica in the mixed oxides] with different \{n(Ti)\}/n(Si) ratios was prepared with ammonia water as a hydrolysis catalyst. The photocatalysts prepared were characterized by XRD, thermal analysis, FTIR, UV-Vis and SPS. The characterization results of FTIR and UV-Vis spectra show that Ti atoms were gradually changed from octahedral coordination to tetrahedral coordination with the addition of silica, which is not beneficial for obtaining strong Brnsted acidity and higher photocatalytic activity. The photocatalytic activity experiments, which were conducted by using heptane(or SO 2) as the model reactant, showed that TiO 2-SiO 2 containing a suitable amount of silica can exhibit much higher photocatalytic activity than pure TiO 2. The enhanced photocatalytic activity can be attributed to three following factors: (1) smaller crystalline size; (2) higher thermal stability; (3) the new strong Brnsted acidity.展开更多
Photocatalytic oxidation kinetics of thiophene in n-octane/water extraction system was studied with fluorine and ferric ion codoped nano-TiO_(2)(nano-F^-/Fe^(3+)/TiO_(2))powders used as the photocatalyst.Effects of in...Photocatalytic oxidation kinetics of thiophene in n-octane/water extraction system was studied with fluorine and ferric ion codoped nano-TiO_(2)(nano-F^-/Fe^(3+)/TiO_(2))powders used as the photocatalyst.Effects of initial concentration of thiophene and additional dosage of F^-/Fe^(3+)/TiO_(2)on the reaction rate constant and half-life were investigated.The results showed that the appropriately added dosage of F^-/Fe^(3+)/TiO_(2)was 0.1 g in the 100-mL reaction system and the photooxidative kinetics of thiophene in the presence of F^-/Fe^(3+)/TiO_(2)catalyst was of first-order with a rate constant of 0.6508 h^(-1)and a half-life of 1.0651 h.The desulfurization rate of thiophene was 98.1%in 5 h and the sulfur content could be reduced from 800 ppm to 15 ppm.The reaction rate constant increased with a decreasing initial concentration of thiophene.展开更多
La_(2)O_(3)/Bi_(2)O_(3)photocatalysts were prepared by impregnation of Bi_(2)O_(3)with an aqueous solution of lanthanum precursor followed by calcination at different temperatures.The composite materials were used for...La_(2)O_(3)/Bi_(2)O_(3)photocatalysts were prepared by impregnation of Bi_(2)O_(3)with an aqueous solution of lanthanum precursor followed by calcination at different temperatures.The composite materials were used for the first time for the photocatalytic removal of Hg~0 from a simulated flue gas under UV light irradiation.The results showed that the sample containing 6 wt.%La_(2)O_(3)and calcined at 500°C has the highest dispersion of the active sites,which was promoted by the strong interaction with the support(i.e.,the formation of Bi-O-La species).Since they are fully accessible on the surface,the material also exhibits excellent optical properties while the heterojunction formed in La_(2)O_(3)/Bi_(2)O_(3)promotes the separation and migration of photoelectron-hole pairs and thus Hg~0 oxidation efficiency is enhanced.The effects of the various factors(e.g.,the reaction temperature and composition of the simulated flue gas(i.e.,O_(2),NO,H_(2)O,and SO_(2)))on the efficiency of the Hg~0 photocatalytic oxidation were investigated.The results demonstrated that O_(2)and SO_(2)enhanced the efficiency of the reaction while the reaction temperature,NO,and H_(2)O had an inhibitory effect.展开更多
A new kind of porous nano-'IiO_(2)composite films was prepared on the glasssubstrate with the water glass as binders and the sodium fluorosilicate as solidifying reagent.Themorphologies of the films were studied b...A new kind of porous nano-'IiO_(2)composite films was prepared on the glasssubstrate with the water glass as binders and the sodium fluorosilicate as solidifying reagent.Themorphologies of the films were studied by scanning electron microscope(SEM).The UV-Visspcctiophotometer was also used to investigate the absorption of the films.The gas-phasephotocatalytic oxidation of nitrogen oxides on the composite film was carried out in TiO_(2)/UVsystem,and some important factors affecting the photocatalytic oxidation were also studied such asthe catalyst concentration,vapor pressure and the presence of oxygen.The results showed theconversion of NO_x reached 97.5%alter 2 h UV-irradiation.The final product of photo-oxidation wasdetected to be HNO_(3)by FT-IR.The way of photocatalytic oxidation of NO_x was possibly useful inthe practical application.展开更多
A simple and effective method of removing polluted organics in water is reported here.Titanium dioxide is a catalyst in photo-oxidation of monocrotophos.The mechanism of photocatalytic oxidation and the kinetics of th...A simple and effective method of removing polluted organics in water is reported here.Titanium dioxide is a catalyst in photo-oxidation of monocrotophos.The mechanism of photocatalytic oxidation and the kinetics of the reaction were studied. This same principle also leads to the construction of instrument of PTR-FIA analysis for monitoring organic phosphorus and phosphate in water.展开更多
Nitric oxide(NO) from flue gas is hard to remove because of low solubility and reactivity. A new technology for photocatalytic oxidation of NO using ultraviolet(UV)/TiO2/H2O2 process is studied in an efficient laborat...Nitric oxide(NO) from flue gas is hard to remove because of low solubility and reactivity. A new technology for photocatalytic oxidation of NO using ultraviolet(UV)/TiO2/H2O2 process is studied in an efficient laboratory-scale reactor. Effects of several key operational parameters on NO removal efficiency are studied, including TiO2 content, H2O2 initial concentration, UV lamp power, NO initial content, oxygen volume fraction and TiO2/H2O2 solution volume. The results illustrate that the NO removal efficiency increases with the increasing of H2O2 initial concentration or UV lamp power. Meanwhile, a lower NO initial content or a higher TiO2/H2O2 solution volume will result in higher NO removal efficiency. In addition, oxygen volume fraction has a little effect.The highest NO removal efficiency is achieved at the TiO2 content of 0.75 g/L, H2O2 initial concentration of 2.5 mol/L, UV lamp power of 36 W, NO initial content of 206×10-6 and TiO2/H2O2 solution volume of 600 m L. It is beneficial for the development and application of NO removal from coal-fired flue gas with UV/TiO2/H2O2 process.展开更多
Many researchers have studied the photocatalytic oxidation of trace levels of benzene,toluene and xy-lene in air over titania photocatalysts.However,atthe moment,the effectiveness of the photocatalytic oxidation is li...Many researchers have studied the photocatalytic oxidation of trace levels of benzene,toluene and xy-lene in air over titania photocatalysts.However,atthe moment,the effectiveness of the photocatalytic oxidation is limited by the deactivation of photocata-lysts.展开更多
TiO2 was prepared by sol-gel method using tetrabutyl titanate as precursor.TiO2 was loaded on Bi12TiO20.The photocatalyst with different TiO2 loading was calcined at 723 K.The photocatalytic activity of decomposition ...TiO2 was prepared by sol-gel method using tetrabutyl titanate as precursor.TiO2 was loaded on Bi12TiO20.The photocatalyst with different TiO2 loading was calcined at 723 K.The photocatalytic activity of decomposition gaseous benzene was investigated in a batch reactor.The prepared photocatalyst was characterized by UV-vis diffuse reflectance.The result showed that TiO2/Bi12TiO20 absorbed much more ultraviolet light than TiO2 in the ultraviolet light region and showed red shift.The results indicated that the prepared photocatalyst can greatly promote the photocatalytic activity.The 2.0%TiO2/Bi12TiO20 system exhibited the highest photocatalytic activity.展开更多
GC/MS has been used to identify gas phase products and intermediates formed during the gas phase photocatalytic oxidation of trichloroethylene (TCE) on TiO(2) with low BET surface area. A new byproduct, oxalyl cholori...GC/MS has been used to identify gas phase products and intermediates formed during the gas phase photocatalytic oxidation of trichloroethylene (TCE) on TiO(2) with low BET surface area. A new byproduct, oxalyl choloride (ClCOCOCl) was detected together with other byproducts such as COCl(2), CHCl(3), DCAC and C(2)HCl(5). Firstly the method of perturbation on the reaction system was conducted. Very little amount of water was carried into the feed gas and subsequent changes were observed. The discussion based on the product distribution changes led to a postulated mechanism consisting of two stages.展开更多
In recent years, serious heavy oil pollution has frequently occurred in the ocean. Heavy oil has escaped from grounded oil carrier and drifted ashore. Drifted heavy oil contains hazardous chemical such as benzo （a） ...In recent years, serious heavy oil pollution has frequently occurred in the ocean. Heavy oil has escaped from grounded oil carrier and drifted ashore. Drifted heavy oil contains hazardous chemical such as benzo （a） pyrene and other poly aromatic hydrocarbons （PAHs）. These hazardous chemicals have worse affected on sea plants and animals. Thus, it is important to develop effective elimination of hazardous chemicals or drifted petroleum from sea shore. In this study, we have investigated the decomposition of benzo （a） pyrene on artificial sea water using UV/photocatalytic oxidation process. From this study, it was found that about 90% of benzo （a） pyrene on artificial seawater was decomposed by UV/photocatalytic oxidation process. And there were no by-product from decomposition of benzo （a） pyrene. It was supposed that benzo （a） pyrene was completely decomposed using UV/photocatalytic oxidation process.展开更多
文摘In the paper,we report a highly robust and porous bimetallic Ti-MOF(designated Mg_(2)Ti-ABTC)by utiliz-ing a trinuclear[Mg_(2)TiO(COO)_(6)]cluster and a tetradentate H_(4)ABTC(3,3′,5,5′-azobenzene tetracarboxylic acid)ligand.Mg_(2)Ti-ABTC exhibited permanent porosity for N_(2),CO_(2),CH_(4),C_(2)H_(2),C_(2)H_(4),and C_(2)H_(6)gas adsorption.Further-more,Mg_(2)Ti-ABTC exhibited outstanding photocatalytic activity in the oxidation of aromatic sulfides to the corre-sponding sulfoxides under ambient air conditions.Mechanism studies reveal that photoinduced holes(h^(+)),the super-oxide radical(·O_(2)^(-)),and singlet oxygen(^(1)O_(2))are pivotal species involved in the photocatalytic oxidation reaction.
基金The authors thank,DST-FIST,Government of India for fund-ing toward infrastructure and instrumentation facilities at ACIC,St.Joseph’s College(Autonomous),Tiruchirappalli-620002,India.
文摘This research aims to explore the decoration of TiO_(2) substrates with silver nanoparticles as a means of enhancing the photocatalytic oxidation of organic compounds.The results show that decorated TiO_(2) substrates exhibit significantly higher photocatalytic activity in sunlight than undecorated substrates.Morphological analysis is performed,followed by optical and structural characterizations.Scanning electron microscopy analysis of the TiO_(2) reveals many nanotubular structures with particle sizes of∼134.4,148.8,and 132.7 nm at random locations.TiO_(2) is also found to have an absorbance range of 397.6 nm,from which it is known that the photocatalyst reacts in the presence of an ultraviolet source.From the Miller indices of the x-ray diffraction peaks,the preferred crystal orientation is found to be associated with a face-centered cubic structure with a crystallite size of 3.76 nm.Using these promising results,photocatalytic analysis is performed,revealing good degradation characteristics.This investigation reveals that TiO_(2) substrates coated with Ag nanoparticles possess significant potential for application in the photocatalytic oxidation of methylene blue dye,which is a crucial step toward establishing a cleaner environment.
基金the National Natural Science Foun-dation of China(No.22278334)。
文摘For the efficient harnessing of solar energy and mitigation of environmental pollution,the develop-ment and application of semiconductor photocatalysis technology is paramount.Herein,a novel SubPc-Br/CdS supramolecular array with an S-scheme heterojunction was synthesized through the intermolecu-larπ-stacked self-assembly of subphthalocyanine(SubPc-Br)and nanometer cadmium sulfide(CdS).This self-assembly system features a highly structured architecture and excellent stability.Experiments and ground-state differential charge calculations demonstrate that SubPc-Br and CdS form a built-in electric field during the self-assembly process,a critical factor in promoting the dissociation of electrons and holes.Additionally,this study utilized time-dependent density functional theory(TDDFT)to simulate the dynamic adsorption behavior of excited oxygen molecules on the SubPc-Br/CdS interface for the first time.The analysis of molecular charge differential density under different excited states proved that the addi-tion of SubPc-Br molecules not only improves the photocorrosion resistance of CdS in an O2 adsorption environment but also enhances the production of advanced reactive oxygen species under the synergistic action of h+and·O2-.When subjected to visible light,the degradation efficiency of minocycline(MC)achieved 96.8%within 60 min and maintained 80.3%after 5 cycles.In summary,this study highlights the feasibility of creating advanced S-scheme heterojunction photocatalysts through the strategic incor-poration of organic supramolecules with semiconductor catalysts.
基金The National High Technology Research Program of China (863 Program) (No. 2008AA05Z303)the Science and Technology Program of Jiangsu Province (No. BE2010184)the Environmental Protection Scientific Research Subject of Jiangsu Province (No.201031)
文摘In order to remove nitric oxides （NO） from flue gas, experimental studies on the photocatalytic oxidation （PCO） of NO are carried out in an efficient laboratory-scale reactor. Nano-sized TiO2 particles loading on quartz sand are prepared and used as the photocatalyst. Effects of several key operating parameters on NO conversion are investigated, including operating temperature, NO inlet concentration, oxygen percentage, relative humidity and residence time. The results illustrate that the NO inlet concentration, the oxygen percentage and the relative humidity play an important role in the oxidation of NO. A lower NO inlet concentration and a higher oxygen percentage result in a higher NO conversion efficiency. When the relative humidity is 8%, the maximum value of NO conversion efficiency is achieved. In addition, the operating temperature and the residence time have a little effect on the conversion efficiency of NO.
基金supports from National Natural Science Foundation of China(Nos.22172066,22378176)supported by State Key Laboratory of Heavy Oil Processing.Supported by Jiangsu Collaborative Innovation Center of TechnologyMaterial of Water Treatment,Suzhou University of Science and Technology.
文摘Development of clean desulfurization process that combines both efficient and environmentally friendly remains a significant challenge for diesel production.The photocatalytic oxidation desulfurization technology is regarded as a promising process depending on the superior electron transfer and visible light utilization of photocatalyst.Herein,the nonstoichiometry MoO_(3-x)with outstanding photoresponse ability is prepared and modified by imidazole-based ionic liquid[C_(12)mim]Cl to upgrade electronic structure.The interface H-bonding between MoO_(3-x)and[C_(12)mim]Cl regard as electronic transfer channel and the recombination of e^(-)-h^(+)pairs is effectively inhibited with the modification of[C_(12)mim]Cl.Deep desulfurization rate of 96.6%can be reached within 60 min and the MoO_(3-x)/[C_(12)mim]Cl(MoC_(12))photocatalyst demonstrated outstanding cyclic stability within 7 cycles in an extraction coupled photocatalytic oxidation desulfurization(ECPODS)system.The study provides a new perspective on enhancing photocatalytic desulfurization through defect engineering and surface modification.
基金financial support provided by the National Natural Science Foundation of China(No.22172057).
文摘The simultaneous accumulation of photo-holes and the specific activation of substrates present a significant challenge in photo-oxidation.Herein,we propose a dual-channel collaborative catalytic platform based on hollow TiO_(2) microspheres,using Cu single-atom(SA)catalysts and a composite polymer chain,to create separating pathways for unidirectional photogenerated electron/hole extraction.Ferrocene-functionalized graphene quantum dots are incorporated within the polymer chain for driving benzylamine(BA)oxidation.Quasi in situ transient photovoltage and femtosecond transient absorption tests reveal that leveraging the ultrafast charge separation capability of Cu SAs(0.44 ps)not only accelerates hole transport kinetics but also induces requisite Lewis acidity for the adsorption and activation of BA.In an air atmosphere,the rate of imine production reaches 4.81 mmol g^(−1) h^(−1)(selectivity of 98%).This study demonstrates the rational design of an SA/polymer chain dual-driven catalytic platform for optimizing kinetics and precisely controlling photocatalytic transformations in organic chemistry.
文摘A carbon‐doped TiO2/fly ash support(C‐TiO2/FAS)composite photocatalyst was successfully synthesized through sol impregnation and subsequent carbonization.The carbon dopants were derived from the organic species generated during the synthesis of the C‐TiO2/FAS composite.A series of analytical techniques,such as scanning electron microscopy(SEM),attenuated total reflection‐Fourier transform infrared(ATR‐FTIR)spectroscopy,X‐ray photoelectron spectroscopy(XPS),and ultraviolet‐visible diffuse reflectance spectroscopy(UV‐Vis DRS),were used to characterize the properties of the prepared samples.The results indicated that C‐TiO2 was successfully coated on the FAS surface.Coupling between C‐TiO2 and FAS resulted in the formation of Si–O–C and Al–O–Ti bonds at their interface.The formation of Si–O–C and Al–O–Ti bonds gave rise to a positive shift of the valence band edge of C‐TiO2 and enhanced its oxidation capability of photogenerated holes as well as photodegradation efficiency of methyl orange.Moreover,the C‐TiO2/FAS photocatalyst exhibited favorable reusability and separability.This work may provide a new route for tuning the electronic band structure of TiO2.
基金Porject supported by the New Century Excellent Scholar Program of Ministry of Education of China(No.NCET-04-0549)the China Postdoctoral Science Foundation(No.20060401047).
文摘A series of nanosized ion-doped TiO2 catalysts with different ion content （between 0.1 at.% and 1.0 at.%） have been prepared by wet impregnation method and investigated with respect to their behavior for UV photocatalytic oxidation of nitric oxide. The catalytic activity was correlated with structural, electronic and surface examinations of the catalysts using X-ray diffraction analysis （XRD）, ultraviolet-visible （UV-Vis） absorption spectroscopy, transmission electron microscopy （TEM）, energy disperse spectrometer （EDS） and high resolution-transmission electron microscopy （HR-TEM） techniques. An enhancement of the photocatalytic activity was observed for Zn2＋ doping catalyst ranged from 0.1 at.% to 1.0 at.% which was attributed to the lengthened lifetime of electrons and holes. The improvement in photocatalytic activity could be also observed with the low doping concentration of Cr^3＋ （0.1 at.%）. However, the doping of Fe^3＋, Mo^6＋, Mn^2＋ and the high doping concentration of Cr^3＋ had no contribution to photocatalytic activity of nitric oxide.
基金supported by the National Key Research and Development Plan of China (2016YFC0204700)National Natural Science Foundation of China (NSFC-51578488)+3 种基金Zhejiang Provincial "151" Talents Program (2013)Key Project of Zhejiang Provincial Science and Technology Programthe Program for Zhejiang Leading Team of S&T Innovation (2013TD07)the Changjiang Scholar Incentive Program (2009)~~
文摘In this study, a hybrid process using non‐thermal plasma (NTP) and photocatalytic oxidation (PCO) was adopted for the degradation of gas‐phase toluene using TiO2 as the photocatalyst. To discover the synergetic effect between NTP and PCO, the performances of both sole (O3, UV, NTP, and PCO) and combined (O3 + TiO2, O3 + UV, NTP + UV, O3 + PCO, and NTP + PCO) processes were investigated from different perspectives, such as the toluene removal efficiency, selectivity of COx, mineralization rate, ozone utilization, and the generation of by‐products. The toluene removal efficiency of the combined NTP + PCO process was 80.2%, which was much higher than that of a sole degradation process such as NTP (18.8%) and PCO (13.4%). The selectivity of CO2 and the ozone utilization efficiency also significantly improved. The amount of by‐products in the gas phase and the carbon‐ based intermediates adsorbed on the catalyst surface dramatically reduced. The improvement in the overall performances of the combined NTP + PCO process was mainly ascribed to the efficient utilization of ozone in the photocatalytic oxidation, and the ozone further acting as an electron acceptor and scavenger, generating more hydroxyl radicals and reducing the recombination of electron‐ hole pairs.
文摘Novel Bi_(2)MoO_(6) nanocrystals with tunable oxygen vacancies have been developed via a facile low-cost approach with the assistance of a glyoxal reductant under solvothermal conditions.With the introduction of oxygen vacancies,the optical absorption of Bi_(2)MoO_(6) is extended and its bandgap narrowed.Oxygen vacancies not only lead to the appearance of a defect band level in the forbidden band but can also result in a minor up-shift of the valence band maximum,promoting the mobility of photogenerated holes.Moreover,oxygen vacancies can act as electron acceptors,temporarily capturing electrons excited by light and reducing the recombination of electrons and holes.At the same time,oxygen vacancies help to capture oxygen,which reacts with the captured photogenerated electrons to generate more superoxide radicals(·O_(2)-)to participate in the reaction,thereby significantly promoting the redox performance of the photocatalyst.From Bi_(2)MoO_(6) containing these oxygen vacancies(OVBMO),excellent photocatalytic performance has been obtained for the oxidation of 1,2,3,4-tetrahydroquinoline to produce quinoline and cause antibiotic degradation.The reaction mechanism of the oxidation of 1,2,3,4-tetrahydroquinoline to quinoline over the OVBMO materials is elucidated in terms of heterogeneous Catal.via a radical pathway.
基金Supported by the National Natural Science Foundation of China(No.2 0 2 770 15 )
文摘A series of TiO 2-XSiO 2[X denotes the molar fraction(%) of silica in the mixed oxides] with different \{n(Ti)\}/n(Si) ratios was prepared with ammonia water as a hydrolysis catalyst. The photocatalysts prepared were characterized by XRD, thermal analysis, FTIR, UV-Vis and SPS. The characterization results of FTIR and UV-Vis spectra show that Ti atoms were gradually changed from octahedral coordination to tetrahedral coordination with the addition of silica, which is not beneficial for obtaining strong Brnsted acidity and higher photocatalytic activity. The photocatalytic activity experiments, which were conducted by using heptane(or SO 2) as the model reactant, showed that TiO 2-SiO 2 containing a suitable amount of silica can exhibit much higher photocatalytic activity than pure TiO 2. The enhanced photocatalytic activity can be attributed to three following factors: (1) smaller crystalline size; (2) higher thermal stability; (3) the new strong Brnsted acidity.
基金the NationalNatural Science Foundation of China(20806021)the Natu-ral Science Foundation of Hebei Province(B2009000678)the Research Foundation of Hebei Province EducationDepartment(2007440)for the financial support of this work
文摘Photocatalytic oxidation kinetics of thiophene in n-octane/water extraction system was studied with fluorine and ferric ion codoped nano-TiO_(2)(nano-F^-/Fe^(3+)/TiO_(2))powders used as the photocatalyst.Effects of initial concentration of thiophene and additional dosage of F^-/Fe^(3+)/TiO_(2)on the reaction rate constant and half-life were investigated.The results showed that the appropriately added dosage of F^-/Fe^(3+)/TiO_(2)was 0.1 g in the 100-mL reaction system and the photooxidative kinetics of thiophene in the presence of F^-/Fe^(3+)/TiO_(2)catalyst was of first-order with a rate constant of 0.6508 h^(-1)and a half-life of 1.0651 h.The desulfurization rate of thiophene was 98.1%in 5 h and the sulfur content could be reduced from 800 ppm to 15 ppm.The reaction rate constant increased with a decreasing initial concentration of thiophene.
基金supported by the National Key Research and Development Program of China(Nos.2017YFC0210500 and 2018YFC0213400)the National Natural Science Foundation of China(Nos.52070090 and 51868030)。
文摘La_(2)O_(3)/Bi_(2)O_(3)photocatalysts were prepared by impregnation of Bi_(2)O_(3)with an aqueous solution of lanthanum precursor followed by calcination at different temperatures.The composite materials were used for the first time for the photocatalytic removal of Hg~0 from a simulated flue gas under UV light irradiation.The results showed that the sample containing 6 wt.%La_(2)O_(3)and calcined at 500°C has the highest dispersion of the active sites,which was promoted by the strong interaction with the support(i.e.,the formation of Bi-O-La species).Since they are fully accessible on the surface,the material also exhibits excellent optical properties while the heterojunction formed in La_(2)O_(3)/Bi_(2)O_(3)promotes the separation and migration of photoelectron-hole pairs and thus Hg~0 oxidation efficiency is enhanced.The effects of the various factors(e.g.,the reaction temperature and composition of the simulated flue gas(i.e.,O_(2),NO,H_(2)O,and SO_(2)))on the efficiency of the Hg~0 photocatalytic oxidation were investigated.The results demonstrated that O_(2)and SO_(2)enhanced the efficiency of the reaction while the reaction temperature,NO,and H_(2)O had an inhibitory effect.
基金Supported by the Key Technologies Research and Development Programme of the Ninth Five year Plan of China(965540301)
文摘A new kind of porous nano-'IiO_(2)composite films was prepared on the glasssubstrate with the water glass as binders and the sodium fluorosilicate as solidifying reagent.Themorphologies of the films were studied by scanning electron microscope(SEM).The UV-Visspcctiophotometer was also used to investigate the absorption of the films.The gas-phasephotocatalytic oxidation of nitrogen oxides on the composite film was carried out in TiO_(2)/UVsystem,and some important factors affecting the photocatalytic oxidation were also studied such asthe catalyst concentration,vapor pressure and the presence of oxygen.The results showed theconversion of NO_x reached 97.5%alter 2 h UV-irradiation.The final product of photo-oxidation wasdetected to be HNO_(3)by FT-IR.The way of photocatalytic oxidation of NO_x was possibly useful inthe practical application.
文摘A simple and effective method of removing polluted organics in water is reported here.Titanium dioxide is a catalyst in photo-oxidation of monocrotophos.The mechanism of photocatalytic oxidation and the kinetics of the reaction were studied. This same principle also leads to the construction of instrument of PTR-FIA analysis for monitoring organic phosphorus and phosphate in water.
基金Project(2011CB201505)supported by the National Key Basic Research Program of ChinaProject(BA2011031)supported by the Special Fund of Transformation of Scientific and Technological Achievements of Jiangsu Province,China
文摘Nitric oxide(NO) from flue gas is hard to remove because of low solubility and reactivity. A new technology for photocatalytic oxidation of NO using ultraviolet(UV)/TiO2/H2O2 process is studied in an efficient laboratory-scale reactor. Effects of several key operational parameters on NO removal efficiency are studied, including TiO2 content, H2O2 initial concentration, UV lamp power, NO initial content, oxygen volume fraction and TiO2/H2O2 solution volume. The results illustrate that the NO removal efficiency increases with the increasing of H2O2 initial concentration or UV lamp power. Meanwhile, a lower NO initial content or a higher TiO2/H2O2 solution volume will result in higher NO removal efficiency. In addition, oxygen volume fraction has a little effect.The highest NO removal efficiency is achieved at the TiO2 content of 0.75 g/L, H2O2 initial concentration of 2.5 mol/L, UV lamp power of 36 W, NO initial content of 206×10-6 and TiO2/H2O2 solution volume of 600 m L. It is beneficial for the development and application of NO removal from coal-fired flue gas with UV/TiO2/H2O2 process.
文摘Many researchers have studied the photocatalytic oxidation of trace levels of benzene,toluene and xy-lene in air over titania photocatalysts.However,atthe moment,the effectiveness of the photocatalytic oxidation is limited by the deactivation of photocata-lysts.
文摘TiO2 was prepared by sol-gel method using tetrabutyl titanate as precursor.TiO2 was loaded on Bi12TiO20.The photocatalyst with different TiO2 loading was calcined at 723 K.The photocatalytic activity of decomposition gaseous benzene was investigated in a batch reactor.The prepared photocatalyst was characterized by UV-vis diffuse reflectance.The result showed that TiO2/Bi12TiO20 absorbed much more ultraviolet light than TiO2 in the ultraviolet light region and showed red shift.The results indicated that the prepared photocatalyst can greatly promote the photocatalytic activity.The 2.0%TiO2/Bi12TiO20 system exhibited the highest photocatalytic activity.
文摘GC/MS has been used to identify gas phase products and intermediates formed during the gas phase photocatalytic oxidation of trichloroethylene (TCE) on TiO(2) with low BET surface area. A new byproduct, oxalyl choloride (ClCOCOCl) was detected together with other byproducts such as COCl(2), CHCl(3), DCAC and C(2)HCl(5). Firstly the method of perturbation on the reaction system was conducted. Very little amount of water was carried into the feed gas and subsequent changes were observed. The discussion based on the product distribution changes led to a postulated mechanism consisting of two stages.
文摘In recent years, serious heavy oil pollution has frequently occurred in the ocean. Heavy oil has escaped from grounded oil carrier and drifted ashore. Drifted heavy oil contains hazardous chemical such as benzo （a） pyrene and other poly aromatic hydrocarbons （PAHs）. These hazardous chemicals have worse affected on sea plants and animals. Thus, it is important to develop effective elimination of hazardous chemicals or drifted petroleum from sea shore. In this study, we have investigated the decomposition of benzo （a） pyrene on artificial sea water using UV/photocatalytic oxidation process. From this study, it was found that about 90% of benzo （a） pyrene on artificial seawater was decomposed by UV/photocatalytic oxidation process. And there were no by-product from decomposition of benzo （a） pyrene. It was supposed that benzo （a） pyrene was completely decomposed using UV/photocatalytic oxidation process.
