Herein,the catalysts of ultrathin g-C_(3)N_(4)surface-modified hollow spherical Bi2MoO6(g-C_(3)N_(4)/Bi2MoO6,abbreviated as CN/BMO)were fabricated by the co-solvothermal method.The variable valence Mo^(5+)/Mo^(6+)ioni...Herein,the catalysts of ultrathin g-C_(3)N_(4)surface-modified hollow spherical Bi2MoO6(g-C_(3)N_(4)/Bi2MoO6,abbreviated as CN/BMO)were fabricated by the co-solvothermal method.The variable valence Mo^(5+)/Mo^(6+)ionic bridge in CN/BMO catalysts can boost the rapid transfer of photogenerated electrons from Bi2MoO6to g-C_(3)N_(4).And the synergy effect of g-C_(3)N_(4)and Bi2MoO6components remarkably enhance CO_(2)adsorption capability.CN/BMO-2 catalyst has the best performances for visible light-driven CO_(2)reduction compared with single Bi2MoO6and g-C_(3)N_(4),i.e.,its amount and selectivity of CO product are 139.50μmol g-1and 96.88%for 9 h,respectively.Based on the results of characterizations and density functional theory calculation,the photocatalytic mechanism for CO_(2)reduction is proposed.The high-efficient separation efficiency of photogenerated electron-hole pairs,induced by variable valence Mo^(5+)/Mo^(6+)ionic bridge,can boost the rate-limiting steps(COOH*-to-CO*and CO*desorption)of selective visible light-driven CO_(2)conversion into CO.It inspires the establishment of efficient photocatalysts for CO_(2)conversion.展开更多
Constructing the stable,low-cost,efficient,and highly adaptable visible light-driven photocatalyst to implement the synergistic effect of photocatalysis and adsorption has been excavated a promising strategy to deal w...Constructing the stable,low-cost,efficient,and highly adaptable visible light-driven photocatalyst to implement the synergistic effect of photocatalysis and adsorption has been excavated a promising strategy to deal with antibiotic pollution in water bodies.Herein,a novel 3 D ternary Z-scheme heterojunction photocatalyst Ni_(2)P/Bi_(2)MoO_(6)/g-C_(3)N_(4)(Ni_(2)P/BMO/CN)was fabricated by a simple solvothermal method in which the broad spectrum antibiotics(mainly tetracyclines and supplemented by quinolones)were used as target pollution sources to evaluate its adsorption and photocatalytic performance.Notably,the Zscheme composite significantly exhibit the enhancement for degradation efficiency of tetracycline and other antibiotic by using Ni_(2)P nanoparticles as electron conductor.Active species capture experiment and electron spin resonance(ESR)technology reveal the mechanism of Z-scheme Ni_(2)P/BMO/CN photocatalytic reaction in detail.In addition,based on the identification of intermediates by liquid chromatography–mass spectroscopy(LC–MS),the possible photocatalytic degradation pathways of TC were proposed.展开更多
Constructing new photocatalysts for the photocatalytic reduction of CO_(2)and efficient degradation of Lev-ofloxacin is of great importance to renewable energy.Here,S-scheme Bi_(2)MoO_(6-x)/MoS_(2)heterojunction nanos...Constructing new photocatalysts for the photocatalytic reduction of CO_(2)and efficient degradation of Lev-ofloxacin is of great importance to renewable energy.Here,S-scheme Bi_(2)MoO_(6-x)/MoS_(2)heterojunction nanospheres containing abundant surface defects(oxygen vacancies)were designed and successfully syn-thesized to enhance CO_(2)photoreduction activity in the absence of other sacrificial agents,co-catalysts or photosensitisers.At the same time,it can efficiently degrade organic pollutants(Levofloxacin).This heterogeneous structure with surface defects provides an abundance of reactive sites,accelerates charge separation and improves oxidation capacity.The improved Bi_(2)MoO_(6-x)/MoS_(2)heterogeneous nanospheres show excellent performance under simulated solar light,with the selectivity and yield of 92.45%and 29.01μmol h−1,respectively,for the generation of CO.Under visible light,the degradation efficiency of levofloxacin hydrochloride(LVX)reached 96.3%within 25 min and remained as high as 95%after three cycles.This work provides a new idea for the design of new S-scheme photocatalysts and an important reference for the preparation of photocatalysts for the efficient photocatalytic reduction of CO_(2)and the efficient degradation of organic pollutants at the same time.展开更多
A novel 2D/2D Bi_(2)MoO_(6)/g-C_(3)N_(4) step-scheme(S-scheme)composite by loading Au as cocatalyst was successfully fabricated using a photoreduction and hydrothermal route.The obtained Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au ...A novel 2D/2D Bi_(2)MoO_(6)/g-C_(3)N_(4) step-scheme(S-scheme)composite by loading Au as cocatalyst was successfully fabricated using a photoreduction and hydrothermal route.The obtained Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au photocatalysts were characterized by X-ray diffraction(XRD),transmission electron microscope(TEM),X-ray photo-electron spectroscopy(XPS),UV–vis diffuse reflectance spectra(UV–vis),Fourier transform infrared spectroscopy(FTIR),photoluminescence(PL),photocurrent response(I-t),and electrochemical impedance spectroscopy(EIS).The HRTEM images revealed that an intimate interface in composites were formed.The optimum photocatalytic activity of Rhodamine B degradation over Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au was about 9.7 times and 13.1 times as high as those of Bi_(2)MoO_(6) and g-C_(3)N_(4),respectively.The notably improved photocatalytic activity of Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au could be mainly ascribed to the abundant active sites and the enhanced separation efficiency of photogenerated carriers in Bi_(2)MoO_(6)/g-C_(3)N_(4) S-scheme system.Notably,Au nanoparticles could act as a co-catalyst to further promote electron transfer and separation from the conduction band of g-C_(3)N_(4).Additionally,a possible step-scheme photocatalytic reaction mechanism of Rh B degradation over Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au was tentatively proposed.PL and transient photocurrent analysis implied that Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au photocatalysts possessed the lower recombination rate of photogenerated carriers compared with pure Bi_(2) MoO_(6) and g-C_(3)N_(4),respectively.The present work is expected to provide useful information in designing 2D/2D S-scheme heterojunction photocatalysts.展开更多
Photocatalytic ammonia generation via nitrogen reduction reaction(NRR)is a green and prospective nitrogen fixation technique.However,NRR is often hampered by the high N_(2) adsorption/activation energies and is accomp...Photocatalytic ammonia generation via nitrogen reduction reaction(NRR)is a green and prospective nitrogen fixation technique.However,NRR is often hampered by the high N_(2) adsorption/activation energies and is accompanied by a slow kinetics oxygen evolution reaction(OER).Herein,a robust Bi_(2)S_(3)/OVBi_(2)MoO_(6)S-scheme heterojunction is constructed using a simple in-situ anion exchange process,which enables oxygen vacancy(OVs)abundant Bi_(2)Mo O_(6) microspheres with surface deposited Bi_(2)S_(3).The asfabricated Bi_(2)S_(3)/OVBi_(2)MoO_(6) functioned as an effective photocatalyst to convert N_(2)-to-NH_(3) under mild conditions.The photocatalytic NH_(3)/NH_(4)^(+) production rate reached 126μmol g_(cat)^(-1)under visible light for2.5 h with 2%of Bi_(2)S_(3)/OVBi_(2)MoO_(6)photocatalyst,which was 8-fold higher than pristine Bi_(2)MoO_(6).Furthermore,the as-fabricated Bi_(2)S_(3)/Bi_(2)MoO_(6)heterojunction exhibited good selectivity,high stability and reproducibility.The excellent photocatalytic NRR performance was ascribed to the Bi_(2)S_(3)/Bi_(2)MoO_(6)heterojunction formed subsequent to the strong interaction between Bi_(2)S_(3)and Bi_(2)MoO_(6).The OVs facilitated the chemical adsorption process allowing activation of N_(2)molecule on the Bi_(2)S_(3)/Bi_(2)MoO_(6).Simultaneously,the S-scheme heterojunction prolonged the lifetime of photogenerated carriers,accelerated the electrons/holes spatial separation and accumulation on the Bi_(2)S_(3)(reduction)and Bi_(2)MoO_(6)side(oxidation),respectively,thus strengthening both OER and NRR half-reactions.This simple in-situ anion exchange method offers a novel technique for strengthening OER and NRR half-reactions in Bi-based photocatalysts for effective photocatalytic ammonia generation.展开更多
A series of unique 3D flower-like Bi_(2)MoO_(6)(BMO)/reduced graphene oxide(rGO)heterostructured composites decorated with varying amounts of Ag nanoparticles(NPs)were fabricated.Their morphological characteristics,st...A series of unique 3D flower-like Bi_(2)MoO_(6)(BMO)/reduced graphene oxide(rGO)heterostructured composites decorated with varying amounts of Ag nanoparticles(NPs)were fabricated.Their morphological characteristics,structural features,energy band structures and photoelectrochemical properties were systematically studied.All the Ag/BMO/rGO ternary composites(AgBGy;y=1%,2%and 3%)demonstrated greater photocatalytic activity towards efficient removal of our selected organic models[methyl orange(MO),rhodamine B(RhB)and phenol],as compared with the BMO/rGO binary composites(BG-x;x=0.25,2,4 and 5).Particularly,AgBG-2%,which was synthesized with the addition of 2 wt% rGO and 2 wt%Ag in BMO,possessed superior photocatalytic activity.The fitted rate constants(k)for the photocatalytic degradation of RhB,MO and phenol using AgBG-2% were estimated to be 0.0286,0.0301 and 0.0165 min^(-1),respectively,which were over one order of magnitude greater than those obtained using pure BMO.Several factors may contribute to the observed enhancement,including greater specific surface area,enhanced light absorption,promoted spatial separation of electronhole(e^(-)-h^(+))pairs and their suppressed recombination,especially benefiting from the synergistic effects among BMO,rGO and Ag NPs.Our work suggests that the rational design of BMO/rGO/Ag ternary composite was an effective strategy to boost the photocatalytic activity of the resulting catalyst towards the highly efficient removal of organic pollutants from water.展开更多
基金supported by the National Natural Science Foundation of China(21972166)the Beijing Natural Science Foundation(2202045)the National Key Research and Development Program of China(2019YFC1907600)。
文摘Herein,the catalysts of ultrathin g-C_(3)N_(4)surface-modified hollow spherical Bi2MoO6(g-C_(3)N_(4)/Bi2MoO6,abbreviated as CN/BMO)were fabricated by the co-solvothermal method.The variable valence Mo^(5+)/Mo^(6+)ionic bridge in CN/BMO catalysts can boost the rapid transfer of photogenerated electrons from Bi2MoO6to g-C_(3)N_(4).And the synergy effect of g-C_(3)N_(4)and Bi2MoO6components remarkably enhance CO_(2)adsorption capability.CN/BMO-2 catalyst has the best performances for visible light-driven CO_(2)reduction compared with single Bi2MoO6and g-C_(3)N_(4),i.e.,its amount and selectivity of CO product are 139.50μmol g-1and 96.88%for 9 h,respectively.Based on the results of characterizations and density functional theory calculation,the photocatalytic mechanism for CO_(2)reduction is proposed.The high-efficient separation efficiency of photogenerated electron-hole pairs,induced by variable valence Mo^(5+)/Mo^(6+)ionic bridge,can boost the rate-limiting steps(COOH*-to-CO*and CO*desorption)of selective visible light-driven CO_(2)conversion into CO.It inspires the establishment of efficient photocatalysts for CO_(2)conversion.
基金financially supported by the National Natural Science Foundation of China(No.21906072,22006057,21671084 and 51902140)the Natural Science Foundation of Jiangsu Province(BK20190982)+2 种基金Henan Postdoctoral Foundation(202003013)“Doctor of Mass entrepreneurship and innovation”Project in Jiangsu Province,Jiangsu 333 talents project funding(BRA2018342)Jiangsu provincial government scholarship for overseas studies,the Doctoral Scientific Research Foundation of Jiangsu University of Science and Technology(China)(1062931806 and 1142931803)。
文摘Constructing the stable,low-cost,efficient,and highly adaptable visible light-driven photocatalyst to implement the synergistic effect of photocatalysis and adsorption has been excavated a promising strategy to deal with antibiotic pollution in water bodies.Herein,a novel 3 D ternary Z-scheme heterojunction photocatalyst Ni_(2)P/Bi_(2)MoO_(6)/g-C_(3)N_(4)(Ni_(2)P/BMO/CN)was fabricated by a simple solvothermal method in which the broad spectrum antibiotics(mainly tetracyclines and supplemented by quinolones)were used as target pollution sources to evaluate its adsorption and photocatalytic performance.Notably,the Zscheme composite significantly exhibit the enhancement for degradation efficiency of tetracycline and other antibiotic by using Ni_(2)P nanoparticles as electron conductor.Active species capture experiment and electron spin resonance(ESR)technology reveal the mechanism of Z-scheme Ni_(2)P/BMO/CN photocatalytic reaction in detail.In addition,based on the identification of intermediates by liquid chromatography–mass spectroscopy(LC–MS),the possible photocatalytic degradation pathways of TC were proposed.
基金supported by the Anhui Provincial Natural Science Foundation of China(No.1508085SME219).
文摘Constructing new photocatalysts for the photocatalytic reduction of CO_(2)and efficient degradation of Lev-ofloxacin is of great importance to renewable energy.Here,S-scheme Bi_(2)MoO_(6-x)/MoS_(2)heterojunction nanospheres containing abundant surface defects(oxygen vacancies)were designed and successfully syn-thesized to enhance CO_(2)photoreduction activity in the absence of other sacrificial agents,co-catalysts or photosensitisers.At the same time,it can efficiently degrade organic pollutants(Levofloxacin).This heterogeneous structure with surface defects provides an abundance of reactive sites,accelerates charge separation and improves oxidation capacity.The improved Bi_(2)MoO_(6-x)/MoS_(2)heterogeneous nanospheres show excellent performance under simulated solar light,with the selectivity and yield of 92.45%and 29.01μmol h−1,respectively,for the generation of CO.Under visible light,the degradation efficiency of levofloxacin hydrochloride(LVX)reached 96.3%within 25 min and remained as high as 95%after three cycles.This work provides a new idea for the design of new S-scheme photocatalysts and an important reference for the preparation of photocatalysts for the efficient photocatalytic reduction of CO_(2)and the efficient degradation of organic pollutants at the same time.
基金supported by the National Natural Science Foundation of China(22278169,51973078)the Excellent Scientific Research and Innovation Team of Education Department of Anhui Province(2022AH010028)+1 种基金the major projects of Education Department of Anhui Province(2022AH040068)Anhui Provincial Quality Engineering Project(2022sx134)。
基金financially supported by the Fundamental Research Funds for the Central Universities(No.JUSRP51716A)the National Natural Science Foundation of China(Nos.21203077 and 21773099)the financially support from the Qing Lan Project of Jiangsu Province。
文摘A novel 2D/2D Bi_(2)MoO_(6)/g-C_(3)N_(4) step-scheme(S-scheme)composite by loading Au as cocatalyst was successfully fabricated using a photoreduction and hydrothermal route.The obtained Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au photocatalysts were characterized by X-ray diffraction(XRD),transmission electron microscope(TEM),X-ray photo-electron spectroscopy(XPS),UV–vis diffuse reflectance spectra(UV–vis),Fourier transform infrared spectroscopy(FTIR),photoluminescence(PL),photocurrent response(I-t),and electrochemical impedance spectroscopy(EIS).The HRTEM images revealed that an intimate interface in composites were formed.The optimum photocatalytic activity of Rhodamine B degradation over Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au was about 9.7 times and 13.1 times as high as those of Bi_(2)MoO_(6) and g-C_(3)N_(4),respectively.The notably improved photocatalytic activity of Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au could be mainly ascribed to the abundant active sites and the enhanced separation efficiency of photogenerated carriers in Bi_(2)MoO_(6)/g-C_(3)N_(4) S-scheme system.Notably,Au nanoparticles could act as a co-catalyst to further promote electron transfer and separation from the conduction band of g-C_(3)N_(4).Additionally,a possible step-scheme photocatalytic reaction mechanism of Rh B degradation over Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au was tentatively proposed.PL and transient photocurrent analysis implied that Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au photocatalysts possessed the lower recombination rate of photogenerated carriers compared with pure Bi_(2) MoO_(6) and g-C_(3)N_(4),respectively.The present work is expected to provide useful information in designing 2D/2D S-scheme heterojunction photocatalysts.
基金financially supported by the National Natural Science Foundation of China(Nos.22168040,21666039,21663030)the Open Project of State Key Laboratory of Organic-Inorganic Composites Beijing Key Laboratory,Beijing University of Chemical Technology Beijing(No.oic-201901009)+3 种基金the Project of Science&Technology Office of Shaanxi Province(Nos.2018TSCXL-NY-02–01,2020JQ-791)the Project of Yan’an Science and Technology Bureau(No.2018KG-04)the Graduate Innovation Project of Yan’an University(No.YCX2020005)the Open Project of Chongqing Key Laboratory of Inorganic Special Functional Materials,Yangtze Normal University(No.KFKT202001)。
文摘Photocatalytic ammonia generation via nitrogen reduction reaction(NRR)is a green and prospective nitrogen fixation technique.However,NRR is often hampered by the high N_(2) adsorption/activation energies and is accompanied by a slow kinetics oxygen evolution reaction(OER).Herein,a robust Bi_(2)S_(3)/OVBi_(2)MoO_(6)S-scheme heterojunction is constructed using a simple in-situ anion exchange process,which enables oxygen vacancy(OVs)abundant Bi_(2)Mo O_(6) microspheres with surface deposited Bi_(2)S_(3).The asfabricated Bi_(2)S_(3)/OVBi_(2)MoO_(6) functioned as an effective photocatalyst to convert N_(2)-to-NH_(3) under mild conditions.The photocatalytic NH_(3)/NH_(4)^(+) production rate reached 126μmol g_(cat)^(-1)under visible light for2.5 h with 2%of Bi_(2)S_(3)/OVBi_(2)MoO_(6)photocatalyst,which was 8-fold higher than pristine Bi_(2)MoO_(6).Furthermore,the as-fabricated Bi_(2)S_(3)/Bi_(2)MoO_(6)heterojunction exhibited good selectivity,high stability and reproducibility.The excellent photocatalytic NRR performance was ascribed to the Bi_(2)S_(3)/Bi_(2)MoO_(6)heterojunction formed subsequent to the strong interaction between Bi_(2)S_(3)and Bi_(2)MoO_(6).The OVs facilitated the chemical adsorption process allowing activation of N_(2)molecule on the Bi_(2)S_(3)/Bi_(2)MoO_(6).Simultaneously,the S-scheme heterojunction prolonged the lifetime of photogenerated carriers,accelerated the electrons/holes spatial separation and accumulation on the Bi_(2)S_(3)(reduction)and Bi_(2)MoO_(6)side(oxidation),respectively,thus strengthening both OER and NRR half-reactions.This simple in-situ anion exchange method offers a novel technique for strengthening OER and NRR half-reactions in Bi-based photocatalysts for effective photocatalytic ammonia generation.
基金financially supported by National Natural Science Foundation of China(Nos.21607064 and 21707055)the Youth Key Project of Nature Science Foundation of Jiangxi Province(Nos.20192ACBL20014 and 20192ACBL21011)+2 种基金the Natural Science Foundation of Jiangxi Province(Nos.20181BAB203018 and 20181BAB213010)Qingjiang Youth Talent Program(No.JXUSTQJYX20170005)the scholarship under China S cholarship Council(No.201803000004)。
文摘A series of unique 3D flower-like Bi_(2)MoO_(6)(BMO)/reduced graphene oxide(rGO)heterostructured composites decorated with varying amounts of Ag nanoparticles(NPs)were fabricated.Their morphological characteristics,structural features,energy band structures and photoelectrochemical properties were systematically studied.All the Ag/BMO/rGO ternary composites(AgBGy;y=1%,2%and 3%)demonstrated greater photocatalytic activity towards efficient removal of our selected organic models[methyl orange(MO),rhodamine B(RhB)and phenol],as compared with the BMO/rGO binary composites(BG-x;x=0.25,2,4 and 5).Particularly,AgBG-2%,which was synthesized with the addition of 2 wt% rGO and 2 wt%Ag in BMO,possessed superior photocatalytic activity.The fitted rate constants(k)for the photocatalytic degradation of RhB,MO and phenol using AgBG-2% were estimated to be 0.0286,0.0301 and 0.0165 min^(-1),respectively,which were over one order of magnitude greater than those obtained using pure BMO.Several factors may contribute to the observed enhancement,including greater specific surface area,enhanced light absorption,promoted spatial separation of electronhole(e^(-)-h^(+))pairs and their suppressed recombination,especially benefiting from the synergistic effects among BMO,rGO and Ag NPs.Our work suggests that the rational design of BMO/rGO/Ag ternary composite was an effective strategy to boost the photocatalytic activity of the resulting catalyst towards the highly efficient removal of organic pollutants from water.
