With the objectives of enhancing the stability,optical properties and visible-light photocatalytic activity of photocatalysts,we modified oxygen vacancy-rich zinc oxide（Vo-ZnO） with graphitic carbon nitride（g-C3N4...With the objectives of enhancing the stability,optical properties and visible-light photocatalytic activity of photocatalysts,we modified oxygen vacancy-rich zinc oxide（Vo-ZnO） with graphitic carbon nitride（g-C3N4）. The resulting g-C3N4/Vo-ZnO hybrid photocatalysts showed higher visible-light photocatalytic activity than pure Vo-ZnO and g-C3N4. The hybrid photocatalyst with a g-C3N4 content of 1 wt% exhibited the highest photocatalytic degradation activity under visible-light irradiation（λ≥ 400 nm）. In addition,the g-C3N4/Vo-ZnO photocatalyst was not deactivated after five cycles of methyl orange degradation,indicating that it is stable under light irradiation. Finally,a Z-scheme mechanism for the enhanced photocatalytic activity and stability of the g-C3N4/Vo-ZnO hybrid photocatalyst was proposed. The fast charge separation and transport within the g-C3N4/Vo-ZnO hybrid photocatalyst were attributed as the origins of its enhanced photocatalytic performance.展开更多
Pure bismuth（Bi） metal-modified graphitic carbon nitride（g-C3N4） composites（Bi-CN） with a pomegranate-like structure were prepared by an in situ method.The Bi-CN composites were used as photocatalysts for the ox...Pure bismuth（Bi） metal-modified graphitic carbon nitride（g-C3N4） composites（Bi-CN） with a pomegranate-like structure were prepared by an in situ method.The Bi-CN composites were used as photocatalysts for the oxidation of nitric oxide（NO） under visible-light irradiation.The inclusion of pure Bi metal in the g-C3N4 layers markedly improved the light absorption of the Bi-CN composites from the ultraviolet to the near-infrared region because of the typical surface plasmon resonance of Bi metal.The separation and transfer of photogenerated charge carriers were greatly accelerated by the presence of built-in Mott-Schottky effects at the interface between Bi metal and g-C3N4.As a result,the Bi-CN composite photocatalysts exhibited considerably enhanced efficiency in the photocatalytic removal of NO compared with that of Bi metal or g-C3N4 alone.The pomegranate-like structure of the Bi-CN composites and an explanation for their improved photocatalytic activity were proposed.This work not only provides a design for highly efficient g-C3N4-based photocatalysts through modification with Bi metal,but also offers new insights into the mechanistic understanding of g-C3N4-based photo catalysis.展开更多
A one-pot method for the preparation of g-C3N4/reduced graphene oxide（rGO） composite photocatalysts with controllable band structures is presented.The photocatalysts are characterized by Fouirer transform infrared s...A one-pot method for the preparation of g-C3N4/reduced graphene oxide（rGO） composite photocatalysts with controllable band structures is presented.The photocatalysts are characterized by Fouirer transform infrared spectroscopy,X-ray diffraction,scanning electron microscope,transmission electron microscope,and Mott-Schottky analysis.The valance band（VB） of g-C3N4 exhibits a noticeable positive shift upon hybridizing with rGO,and thus results in a strong photo-oxidation ability.The g-C3N4/rGO composites show a higher photodegradation activity for 2,4-dichlorophenol（2,4-DCP） and rhodamine B（RhB） under visible light irradiation（λ≥420 ran）.The g-C3N4/rGO-1sample exhibits the highest photocatalytic activity,which is 1.49 and 1.52 times higher than that of bulk g-C3N4 for 2,4-DCP and 1.52 times degradation,respectively.The enhanced photocatalytic activity for g-C3N4 originates from the improved visible light usage,enhanced electronic conductivity and photo-oxidation ability by the formed strong π-π stacking interactions with rGO.展开更多
Three kinds of composite alumina refractories were prepared with tabular alumina （3-1 and 1-0 mm） as aggregates,tabular alumina powder,α-Al2 O3 micropowder,and Si powder as matrix,adding 3 mass％ hexagonal boron ni...Three kinds of composite alumina refractories were prepared with tabular alumina （3-1 and 1-0 mm） as aggregates,tabular alumina powder,α-Al2 O3 micropowder,and Si powder as matrix,adding 3 mass％ hexagonal boron nitride （h-BN）,3 mass％ flake graphite and 10 mass％ flake graphite,respectively.Cold physical properties,hot modulus of rupture,oxidation resistance,thermal shock resistance and slag corrosion resistance of the specimens were compared.The results show that：（1） physical properties and hot modulus of rupture of Al2 O3-h-BN refractories are slightly different from those of low carbon Al2 O3-C refractories,but better than those of traditional Al2 O3-C refractories with 10 mass％ graphite ; （2） Al2 O3-h-BN refractories have better thermal shock resistance and oxidation resistance than the carbon containing refractories,while similar slag resistance with low carbon Al2 O3-C refractories ; （3） h-BN can replace flake graphite as a starting material for the preparation of composite alumina refractories,considering the overall properties of the material.展开更多
Rational regulation of stable graphitic carbon nitride(CN)for superior peroxymonosulfate(PMS)activation is important in the catalytic degradation of water contaminants.In this work,the copper oxide and oxygen co-doped...Rational regulation of stable graphitic carbon nitride(CN)for superior peroxymonosulfate(PMS)activation is important in the catalytic degradation of water contaminants.In this work,the copper oxide and oxygen co-doped graphitic carbon nitride(Cu O/O-CN)was prepared via one-step synthesis and applied in activating PMS for oxytetracycline(OTC)degradation,displaying superior catalytic performance.Systematic characterization and theoretical calculations indicated that the synergistic effect between the oxygen site of CN and CuO can modulate the electronic structure of the whole composite further facilitating the formation of non-radical^(1)O_(2)and various reactive radicals.Results of the influencing factor experiments revealed that CuO/O-CN has a strong resistance to the environmental impact.The degradation efficiency of OTC in the real water environment even exceeded that in the deionized water.After four successive runs of the optimal catalyst,the OTC removal rate was still as high as 91.3%.This work developed a high-efficiency PMS activator to remove refractory pollutants via both radical pathway and non-radical pathway,which showed a promising potential in the treatment of wastewaters.展开更多
Antimony-doped tin oxide(ATO) nanoparticles with an average size of ～ 6 nm were prepared by co-precipitation and subsequent heat treatment. Graphitic carbon nitride(g-CN)/ATO hybrid nanocomposite was designed by the ...Antimony-doped tin oxide(ATO) nanoparticles with an average size of ～ 6 nm were prepared by co-precipitation and subsequent heat treatment. Graphitic carbon nitride(g-CN)/ATO hybrid nanocomposite was designed by the combination of thermally synthesized g-CN and ATO nanoparticles by ultrasonication. The materials were characterized using N2 adsorption/desorption(BET), X-ray diffraction(XRD), scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), transmission electron microscopy(TEM) and Fourier transform infrared spectroscopy(FTIR). A mixture of five volatile organic compounds(VOCs, chloroform, benzene, toluene, xylene and styrene) was used to compare the adsorption capacity of the samples. The adsorption capacity of ATO nanoparticles was improved by the addition of g-CN. Experimental data showed that, among the five VOCs,chloroform was the least adsorbed, regardless of the samples. The g-CN/ATO showed nearly three times greater adsorption capacity for the VOC mixture than pure ATO. The unchanged efficiency of VOC adsorption during cyclic use demonstrated the completely reversible adsorption and desorption behavior of the nanocomposite at room conditions. This economically and environmentally friendly material can be a practical solution for outdoor and indoor VOC removal.展开更多
High stability and efficient charge separation are two critical factors to construct high-performance photocatalysts.Here,an efficient strategy was provided to fabricate the nanocomposite of graphitic carbon nitride/f...High stability and efficient charge separation are two critical factors to construct high-performance photocatalysts.Here,an efficient strategy was provided to fabricate the nanocomposite of graphitic carbon nitride/ferroferric oxide/reduced graphene oxide(g-C_(3)N_(4)/Fe_(3)O_(4)/RGO).The degradation of rhodamine B(RhB)by g-C_(3)N_(4)/Fe_(3)O_(4)/RGO nanocomposite followed the pseudofirst-order kinetics.The g-C_(3)N_(4)/Fe_(3)O_(4)/RGO nanocomposite exhibited excellent stability and magnetically separable performance.It was ascertained that the quantum efficiency and separation efficiency of photoexcited charge carriers of g-C_(3)N_(4)/Fe_(3)O_(4)/RGO nanocomposite were obviously improved.Particularly,the g-C_(3)N_(4)/Fe_(3)O_(4)/RGO nanocomposite with 3 wt.%RGO presented 100%degradation efficiency under visible light irradiation for 75 min.The remarkable photocatalytic degradation activity is attributed to the synergistic interactions among g-C_(3)N_(4),Fe_(3)O_(4),and RGO,along with the efficient interfacial charge separation.展开更多
The complete decomposition of formaldehyde(HCHO) at ambient temperature is the most potential strategy for HCHO elimination from indoor environment.Herein,extra low content of Pt nanoparticles(0.025 wt%)supported on w...The complete decomposition of formaldehyde(HCHO) at ambient temperature is the most potential strategy for HCHO elimination from indoor environment.Herein,extra low content of Pt nanoparticles(0.025 wt%)supported on water-solubility carbon nitride/ceria(Pt/gC_(3)N_(4)@CeO_(2)) was prepared for gaseous HCHO removal at ambient temperature in a simulated indoor environment.Fluorescent light(8 W) illumination could visibly boost the complete decomposition of HCHO into CO_(2) over Pt/gC_(3)N_(4)@CeO_(2).The cooperative effect in the distinct heterostructure and plenty of surface reactive oxygen species contribute primarily to the enhanced catalytic performance of Pt/g-C_(3)N_(4)@CeO_(2).Moreover,the possible mechanism of HCHO oxidation over Pt/g-C_(3)N_(4)@CeO_(2) assisted by the fluorescent light irradiation was proposed based on the physicochemical and optical characterization as well as the result of in situ diffuse reflectance infrared Fourier transform spectra.This work might shed some light on the potential application of the versatile catalysts for ambient-temperature catalytic decomposition of HCHO by making full use of the indoor energies.展开更多
The ubiquity of micropollutants(MPs)in aquatic environments has attracted increasing concern for public health and ecological security.Compared to conventional biological treatment,photocatalytic processes show more e...The ubiquity of micropollutants(MPs)in aquatic environments has attracted increasing concern for public health and ecological security.Compared to conventional biological treatment,photocatalytic processes show more efficiency in degrading MPs,but they require expensive materials and complicated synthesis processes.This study developed an economic photocatalytic process to degrade micropollutants.We synthesized urea-based graphitic carbon nitride(g-C_(3)N_(4))by a facile one-step pyrolysis method and evaluated the photocatalytic efficiency of carbamazepine(CBZ).Under simulated solar irradiation,g-C_(3)N_(4) could achieve 100% removal efficiency of 0.1 mg/L CBZ in spiked wastewater effluent within 15 min,and 86.5% removal efficiency in wastewater influent after 20 min of irradiation.The porous structure of g-C_(3)N_(4) promoted effective charge separation and mass transport of CBZ near the catalyst surface,enabling a high kinetic rate(0.3662 min^(-1)).Reactive oxygen species trapping experiments revealed that superoxide radicals(O_(2)^(·-))and holes(h^(+))were the major active radicals.Electron paramagnetic resonance(EPR)further confirmed the presence of O_(2)^(·-),·OH,^(1)O_(2) and holes.The pH,light intensity and initial CBZ concentration were found to have significant impacts on the removal efficiency of CBZ.Possible reaction intermediates were identified and the degradation pathway was proposed.Multiple MPs were selected to further demonstrate photocatalytic efficiency of g-C_(3)N_(4).The facile synthesis,superior efficiency,and versatility of g-C_(3)N_(4) make it a promising catalyst for application in tertiary wastewater treatment processes.展开更多
A facile approach to the preparation of a novel magnetically separable H_5PMo_（10）V_2O_（40）/Fe_3O_4/g-C_3N_4（PMoV/Fe_3O_4/g-C_3N_4） nanocomposite by chemical impregnation is demonstrated.The prepared nanocomposi...A facile approach to the preparation of a novel magnetically separable H_5PMo_（10）V_2O_（40）/Fe_3O_4/g-C_3N_4（PMoV/Fe_3O_4/g-C_3N_4） nanocomposite by chemical impregnation is demonstrated.The prepared nanocomposite was characterized and its acidity was measured by potentiometric titration.PMoV/Fe_3O_4/g-C_3N_4 showed high catalytic activity in the selective oxidative desulfurization of sulfides to their corresponding sulfoxides or sulfones.The catalytic oxidation of a dibenzothiophene（DBT）-containing model oil and that of real oil were also studied under optimized conditions.In addition,the effects of various nitrogen compounds,as well as the use of one- and two-ring aromatic hydrocarbons as co-solvents,on the catalytic removal of sulfur from DBT were investigated.The catalyst was easily separated and could be recovered from the reaction mixture by using an external magnetic field.Additionally,the remaining reactants could be separated from the products by simple decantation if an appropriate solvent was chosen for the extraction.The advantages of this nanocatalyst are its high catalytic activity and reusability;it can be used at least four times without considerable loss of activity.展开更多
Ammonia borane(NH_(3)BH_(3))is a reducing agent,able to trap and convert carbon dioxide.In the present work,we used a reactive solid consisting of a mixture of 90 wt.%of NH_(3)BH_(3)and 10 wt.%of palladium chloride,be...Ammonia borane(NH_(3)BH_(3))is a reducing agent,able to trap and convert carbon dioxide.In the present work,we used a reactive solid consisting of a mixture of 90 wt.%of NH_(3)BH_(3)and 10 wt.%of palladium chloride,because the mixture reacts in a fast and exothermic way while releasing H2 and generating catalytic Pd0.We took advantage of such reactivity to trap and convert CO_(2)(7 bar),knowing besides that Pd0 is a CO_(2)hydrogenation catalyst.The operation(i.e.stage 1)was effective:BNH polymers,and B−O,C=O,C−O,and C−H bonds(like in BOCH_(3)and BOOCH groups)were identified.We then(in stage 2)pyrolyzed the as-obtained solid at 1250℃ and washed it with water.In doing so,we isolated cyclotriboric acid H_(3)B3O6(stemming from B2O3 formed at 1250℃),hexagonal boron nitride,and graphitic carbon.In conclusion,the stage 1 showed that CO_(2)can be‘trapped’and converted,resulting in the formation of BOCH_(3)and BOOCH groups(possible sources of methanol and formic acid),and the stage 2 showed that CO_(2)transforms into graphitic carbon.展开更多
Graphitic carbon nitride（g-C3N4） with efficient photocatalytic activity was synthesized through thermal polymerization of thiourea with the addition of water（CN-W） or ethanol（CN-E） at 550 ℃for 2 h.The physicoch...Graphitic carbon nitride（g-C3N4） with efficient photocatalytic activity was synthesized through thermal polymerization of thiourea with the addition of water（CN-W） or ethanol（CN-E） at 550 ℃for 2 h.The physicochemical properties of the g-C3N4 were investigated by X-ray diffraction,transmission electron microscopy,ultraviolet-visible spectroscopy,photoluminescence spectroscopy,diffuse-reflection spectroscopy,BET and BJH surface area characterization,and elemental analysis.The carbon content was found to have self-doped into the g-C3N4 matrix during the thermal polymerization of thiourea and ethanol.CN-W and CN-E showed considerably enhanced visible-light photocatalytic activity,with NO removal percentages of 37.2%and 48.3%,respectively.Compared with pure g-C3N4,both the short and long lifetimes of the charge carriers in CN-W and CN-E were found to be prolonged.The mechanism of improved visible-light photocatalytic activity was deduced.The present work may provide a facile route to optimize the microstructure of g-C3N4photocatalysts for high-performance environmental and energy applications.展开更多
An immobilized Cu2O/g-C3N4 heterojunction film was successfully made on an FTO substrate by electrophoretic deposition of g-C3N4 on a Cu2O thin film.The photoelectrochemical（PEC） performance for water splitting by t...An immobilized Cu2O/g-C3N4 heterojunction film was successfully made on an FTO substrate by electrophoretic deposition of g-C3N4 on a Cu2O thin film.The photoelectrochemical（PEC） performance for water splitting by the Cu2O/g-C3N4 film was better than pure g-C3N4 and pure Cu2O film.Under-0.4 V external bias and visible light irradiation,the photocurrent density and PEC hydrogen evolution efficiency of the optimized Cu2O/g-C3N4 film was-1.38 mA/cm^2 and 0.48 mL h^-1 cm^-2,respectively.The enhanced PEC performance of Cu2O/g-C3N4 was attributed to the synergistic effect of light coupling and a matching energy band structure between g-C3N4 and Cu2O as well as the external bias.展开更多
基金supported by the National Basic Research Program of China(2011CB933700)the National Natural Science Foundation of China(21271165)~~
文摘With the objectives of enhancing the stability,optical properties and visible-light photocatalytic activity of photocatalysts,we modified oxygen vacancy-rich zinc oxide（Vo-ZnO） with graphitic carbon nitride（g-C3N4）. The resulting g-C3N4/Vo-ZnO hybrid photocatalysts showed higher visible-light photocatalytic activity than pure Vo-ZnO and g-C3N4. The hybrid photocatalyst with a g-C3N4 content of 1 wt% exhibited the highest photocatalytic degradation activity under visible-light irradiation（λ≥ 400 nm）. In addition,the g-C3N4/Vo-ZnO photocatalyst was not deactivated after five cycles of methyl orange degradation,indicating that it is stable under light irradiation. Finally,a Z-scheme mechanism for the enhanced photocatalytic activity and stability of the g-C3N4/Vo-ZnO hybrid photocatalyst was proposed. The fast charge separation and transport within the g-C3N4/Vo-ZnO hybrid photocatalyst were attributed as the origins of its enhanced photocatalytic performance.
基金supported by the National Program on Key Basic Research Project (2016YFA0203000)the Early Career Scheme (ECS 809813) from the Research Grant Council, Hong Kong SAR Government+2 种基金the Croucher Foundation Visitorship for PRC Scholars 2015/16 at The Education University of Hong Kongthe National Natural Science Foundation of China (51672312, 21373275)the Program for New Century Excellent Talents in University (NCET-12-0668)~~
文摘Pure bismuth（Bi） metal-modified graphitic carbon nitride（g-C3N4） composites（Bi-CN） with a pomegranate-like structure were prepared by an in situ method.The Bi-CN composites were used as photocatalysts for the oxidation of nitric oxide（NO） under visible-light irradiation.The inclusion of pure Bi metal in the g-C3N4 layers markedly improved the light absorption of the Bi-CN composites from the ultraviolet to the near-infrared region because of the typical surface plasmon resonance of Bi metal.The separation and transfer of photogenerated charge carriers were greatly accelerated by the presence of built-in Mott-Schottky effects at the interface between Bi metal and g-C3N4.As a result,the Bi-CN composite photocatalysts exhibited considerably enhanced efficiency in the photocatalytic removal of NO compared with that of Bi metal or g-C3N4 alone.The pomegranate-like structure of the Bi-CN composites and an explanation for their improved photocatalytic activity were proposed.This work not only provides a design for highly efficient g-C3N4-based photocatalysts through modification with Bi metal,but also offers new insights into the mechanistic understanding of g-C3N4-based photo catalysis.
基金supported by the National Natural Science Foundation of China (21577132)the Fundamental Research Funds for the Central Universities (2652015225)+1 种基金National High Technology Research and Development Program of China (2012AA062701)Students Innovation and Entrepreneurship Training Program 2015 of China University of Geosciences (201511415069),Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes~~
文摘A one-pot method for the preparation of g-C3N4/reduced graphene oxide（rGO） composite photocatalysts with controllable band structures is presented.The photocatalysts are characterized by Fouirer transform infrared spectroscopy,X-ray diffraction,scanning electron microscope,transmission electron microscope,and Mott-Schottky analysis.The valance band（VB） of g-C3N4 exhibits a noticeable positive shift upon hybridizing with rGO,and thus results in a strong photo-oxidation ability.The g-C3N4/rGO composites show a higher photodegradation activity for 2,4-dichlorophenol（2,4-DCP） and rhodamine B（RhB） under visible light irradiation（λ≥420 ran）.The g-C3N4/rGO-1sample exhibits the highest photocatalytic activity,which is 1.49 and 1.52 times higher than that of bulk g-C3N4 for 2,4-DCP and 1.52 times degradation,respectively.The enhanced photocatalytic activity for g-C3N4 originates from the improved visible light usage,enhanced electronic conductivity and photo-oxidation ability by the formed strong π-π stacking interactions with rGO.
文摘Three kinds of composite alumina refractories were prepared with tabular alumina （3-1 and 1-0 mm） as aggregates,tabular alumina powder,α-Al2 O3 micropowder,and Si powder as matrix,adding 3 mass％ hexagonal boron nitride （h-BN）,3 mass％ flake graphite and 10 mass％ flake graphite,respectively.Cold physical properties,hot modulus of rupture,oxidation resistance,thermal shock resistance and slag corrosion resistance of the specimens were compared.The results show that：（1） physical properties and hot modulus of rupture of Al2 O3-h-BN refractories are slightly different from those of low carbon Al2 O3-C refractories,but better than those of traditional Al2 O3-C refractories with 10 mass％ graphite ; （2） Al2 O3-h-BN refractories have better thermal shock resistance and oxidation resistance than the carbon containing refractories,while similar slag resistance with low carbon Al2 O3-C refractories ; （3） h-BN can replace flake graphite as a starting material for the preparation of composite alumina refractories,considering the overall properties of the material.
基金financially supported by the program for the National Natural Science Foundation of China(Nos.52170162,51809090,52100182,52100180)the Natural Science Foundation of Hunan Province,China(Nos.2022JJ10016,2019JJ50077,2021JJ40087)+4 种基金the Science and Technology Innovation Program of Hunan Province(No.2021RC3049)the Fundamental Research Funds for the Central Universities(No.531118010114)the China National Postdoctoral Program for Innovative Talents(No.BX20200119)the Project Funded by China Postdoctoral Science Foundation(No.2021M690961)the Fundamental Research Funds for the Central Universities(No.531118010114)。
文摘Rational regulation of stable graphitic carbon nitride(CN)for superior peroxymonosulfate(PMS)activation is important in the catalytic degradation of water contaminants.In this work,the copper oxide and oxygen co-doped graphitic carbon nitride(Cu O/O-CN)was prepared via one-step synthesis and applied in activating PMS for oxytetracycline(OTC)degradation,displaying superior catalytic performance.Systematic characterization and theoretical calculations indicated that the synergistic effect between the oxygen site of CN and CuO can modulate the electronic structure of the whole composite further facilitating the formation of non-radical^(1)O_(2)and various reactive radicals.Results of the influencing factor experiments revealed that CuO/O-CN has a strong resistance to the environmental impact.The degradation efficiency of OTC in the real water environment even exceeded that in the deionized water.After four successive runs of the optimal catalyst,the OTC removal rate was still as high as 91.3%.This work developed a high-efficiency PMS activator to remove refractory pollutants via both radical pathway and non-radical pathway,which showed a promising potential in the treatment of wastewaters.
基金supported by a grant from the Korean Ministry of Education, Science, and Technology (MEST)Republic of Korea through the National Research Foundation (NRF) (No. 2017-R1C1B2011968)
文摘Antimony-doped tin oxide(ATO) nanoparticles with an average size of ～ 6 nm were prepared by co-precipitation and subsequent heat treatment. Graphitic carbon nitride(g-CN)/ATO hybrid nanocomposite was designed by the combination of thermally synthesized g-CN and ATO nanoparticles by ultrasonication. The materials were characterized using N2 adsorption/desorption(BET), X-ray diffraction(XRD), scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), transmission electron microscopy(TEM) and Fourier transform infrared spectroscopy(FTIR). A mixture of five volatile organic compounds(VOCs, chloroform, benzene, toluene, xylene and styrene) was used to compare the adsorption capacity of the samples. The adsorption capacity of ATO nanoparticles was improved by the addition of g-CN. Experimental data showed that, among the five VOCs,chloroform was the least adsorbed, regardless of the samples. The g-CN/ATO showed nearly three times greater adsorption capacity for the VOC mixture than pure ATO. The unchanged efficiency of VOC adsorption during cyclic use demonstrated the completely reversible adsorption and desorption behavior of the nanocomposite at room conditions. This economically and environmentally friendly material can be a practical solution for outdoor and indoor VOC removal.
基金This work was supported by the National Natural Science Foundation of China(Nos.21667019 and 22066017).
文摘High stability and efficient charge separation are two critical factors to construct high-performance photocatalysts.Here,an efficient strategy was provided to fabricate the nanocomposite of graphitic carbon nitride/ferroferric oxide/reduced graphene oxide(g-C_(3)N_(4)/Fe_(3)O_(4)/RGO).The degradation of rhodamine B(RhB)by g-C_(3)N_(4)/Fe_(3)O_(4)/RGO nanocomposite followed the pseudofirst-order kinetics.The g-C_(3)N_(4)/Fe_(3)O_(4)/RGO nanocomposite exhibited excellent stability and magnetically separable performance.It was ascertained that the quantum efficiency and separation efficiency of photoexcited charge carriers of g-C_(3)N_(4)/Fe_(3)O_(4)/RGO nanocomposite were obviously improved.Particularly,the g-C_(3)N_(4)/Fe_(3)O_(4)/RGO nanocomposite with 3 wt.%RGO presented 100%degradation efficiency under visible light irradiation for 75 min.The remarkable photocatalytic degradation activity is attributed to the synergistic interactions among g-C_(3)N_(4),Fe_(3)O_(4),and RGO,along with the efficient interfacial charge separation.
基金financially supported by the National Natural Science Foundation of China(No.21871111)the Excellent Youth Foundation of Hubei Province of China(No.2019CFA078)。
文摘The complete decomposition of formaldehyde(HCHO) at ambient temperature is the most potential strategy for HCHO elimination from indoor environment.Herein,extra low content of Pt nanoparticles(0.025 wt%)supported on water-solubility carbon nitride/ceria(Pt/gC_(3)N_(4)@CeO_(2)) was prepared for gaseous HCHO removal at ambient temperature in a simulated indoor environment.Fluorescent light(8 W) illumination could visibly boost the complete decomposition of HCHO into CO_(2) over Pt/gC_(3)N_(4)@CeO_(2).The cooperative effect in the distinct heterostructure and plenty of surface reactive oxygen species contribute primarily to the enhanced catalytic performance of Pt/g-C_(3)N_(4)@CeO_(2).Moreover,the possible mechanism of HCHO oxidation over Pt/g-C_(3)N_(4)@CeO_(2) assisted by the fluorescent light irradiation was proposed based on the physicochemical and optical characterization as well as the result of in situ diffuse reflectance infrared Fourier transform spectra.This work might shed some light on the potential application of the versatile catalysts for ambient-temperature catalytic decomposition of HCHO by making full use of the indoor energies.
基金funding support through the project DP 170104330the support by Australian Research Council Future Fellowship(FT170100196).
文摘The ubiquity of micropollutants(MPs)in aquatic environments has attracted increasing concern for public health and ecological security.Compared to conventional biological treatment,photocatalytic processes show more efficiency in degrading MPs,but they require expensive materials and complicated synthesis processes.This study developed an economic photocatalytic process to degrade micropollutants.We synthesized urea-based graphitic carbon nitride(g-C_(3)N_(4))by a facile one-step pyrolysis method and evaluated the photocatalytic efficiency of carbamazepine(CBZ).Under simulated solar irradiation,g-C_(3)N_(4) could achieve 100% removal efficiency of 0.1 mg/L CBZ in spiked wastewater effluent within 15 min,and 86.5% removal efficiency in wastewater influent after 20 min of irradiation.The porous structure of g-C_(3)N_(4) promoted effective charge separation and mass transport of CBZ near the catalyst surface,enabling a high kinetic rate(0.3662 min^(-1)).Reactive oxygen species trapping experiments revealed that superoxide radicals(O_(2)^(·-))and holes(h^(+))were the major active radicals.Electron paramagnetic resonance(EPR)further confirmed the presence of O_(2)^(·-),·OH,^(1)O_(2) and holes.The pH,light intensity and initial CBZ concentration were found to have significant impacts on the removal efficiency of CBZ.Possible reaction intermediates were identified and the degradation pathway was proposed.Multiple MPs were selected to further demonstrate photocatalytic efficiency of g-C_(3)N_(4).The facile synthesis,superior efficiency,and versatility of g-C_(3)N_(4) make it a promising catalyst for application in tertiary wastewater treatment processes.
基金the Razi University Research Council for support of this work
文摘A facile approach to the preparation of a novel magnetically separable H_5PMo_（10）V_2O_（40）/Fe_3O_4/g-C_3N_4（PMoV/Fe_3O_4/g-C_3N_4） nanocomposite by chemical impregnation is demonstrated.The prepared nanocomposite was characterized and its acidity was measured by potentiometric titration.PMoV/Fe_3O_4/g-C_3N_4 showed high catalytic activity in the selective oxidative desulfurization of sulfides to their corresponding sulfoxides or sulfones.The catalytic oxidation of a dibenzothiophene（DBT）-containing model oil and that of real oil were also studied under optimized conditions.In addition,the effects of various nitrogen compounds,as well as the use of one- and two-ring aromatic hydrocarbons as co-solvents,on the catalytic removal of sulfur from DBT were investigated.The catalyst was easily separated and could be recovered from the reaction mixture by using an external magnetic field.Additionally,the remaining reactants could be separated from the products by simple decantation if an appropriate solvent was chosen for the extraction.The advantages of this nanocatalyst are its high catalytic activity and reusability;it can be used at least four times without considerable loss of activity.
基金supported by TUBITAK(Project No.218M181)and CAMPUS FRANCE PHC BOSPHORUS(Project No.42161TB).CACM.and U.B.D.want to acknowledge the CONACyT(Mexican National Council for Science and Technology)for the scholarship of CA.CM(2017-2021).
文摘Ammonia borane(NH_(3)BH_(3))is a reducing agent,able to trap and convert carbon dioxide.In the present work,we used a reactive solid consisting of a mixture of 90 wt.%of NH_(3)BH_(3)and 10 wt.%of palladium chloride,because the mixture reacts in a fast and exothermic way while releasing H2 and generating catalytic Pd0.We took advantage of such reactivity to trap and convert CO_(2)(7 bar),knowing besides that Pd0 is a CO_(2)hydrogenation catalyst.The operation(i.e.stage 1)was effective:BNH polymers,and B−O,C=O,C−O,and C−H bonds(like in BOCH_(3)and BOOCH groups)were identified.We then(in stage 2)pyrolyzed the as-obtained solid at 1250℃ and washed it with water.In doing so,we isolated cyclotriboric acid H_(3)B3O6(stemming from B2O3 formed at 1250℃),hexagonal boron nitride,and graphitic carbon.In conclusion,the stage 1 showed that CO_(2)can be‘trapped’and converted,resulting in the formation of BOCH_(3)and BOOCH groups(possible sources of methanol and formic acid),and the stage 2 showed that CO_(2)transforms into graphitic carbon.
基金supported by the National Natural Science Foundation of China(51073172)the Hunan Provincial Natural Science Foundation for Distinguished Young Scholars(14JJ1001)~~
基金supported by the China Postdoctoral Science Foundation Funded Project (2016M592642)Project from Chongqing Education Commission (KJ1600305)+3 种基金Chongqing Basic Science and Advanced Technology Research (cstc2016jcyjAX0003)the Start-up Foundation for Doctors of Chongqing Normal University (15XLB010, 15XLB014)the National Natural Science Foundation of China (51478070, 51108487)the Innovative Research Team of Chongqing (CXTDG201602014)~~
文摘Graphitic carbon nitride（g-C3N4） with efficient photocatalytic activity was synthesized through thermal polymerization of thiourea with the addition of water（CN-W） or ethanol（CN-E） at 550 ℃for 2 h.The physicochemical properties of the g-C3N4 were investigated by X-ray diffraction,transmission electron microscopy,ultraviolet-visible spectroscopy,photoluminescence spectroscopy,diffuse-reflection spectroscopy,BET and BJH surface area characterization,and elemental analysis.The carbon content was found to have self-doped into the g-C3N4 matrix during the thermal polymerization of thiourea and ethanol.CN-W and CN-E showed considerably enhanced visible-light photocatalytic activity,with NO removal percentages of 37.2%and 48.3%,respectively.Compared with pure g-C3N4,both the short and long lifetimes of the charge carriers in CN-W and CN-E were found to be prolonged.The mechanism of improved visible-light photocatalytic activity was deduced.The present work may provide a facile route to optimize the microstructure of g-C3N4photocatalysts for high-performance environmental and energy applications.
基金supported by the National Natural Science Foundation of China (21173088)the Science and Technology Project of Guangdong Province (2014A030312007, 2015A050502012, 2016A010104013)+1 种基金the China Postdoctoral Science Foundation (2016M592493)the Open Research Fund of Hunan Key Laboratory of Applied Environmental Photocatalysis (CCSU-XT-06),Changsha University~~
文摘An immobilized Cu2O/g-C3N4 heterojunction film was successfully made on an FTO substrate by electrophoretic deposition of g-C3N4 on a Cu2O thin film.The photoelectrochemical（PEC） performance for water splitting by the Cu2O/g-C3N4 film was better than pure g-C3N4 and pure Cu2O film.Under-0.4 V external bias and visible light irradiation,the photocurrent density and PEC hydrogen evolution efficiency of the optimized Cu2O/g-C3N4 film was-1.38 mA/cm^2 and 0.48 mL h^-1 cm^-2,respectively.The enhanced PEC performance of Cu2O/g-C3N4 was attributed to the synergistic effect of light coupling and a matching energy band structure between g-C3N4 and Cu2O as well as the external bias.
