Because of its significant toxicological effects on the environment and human health,arsenic(As)is a major global issue.In this study,an Fe-based metal-organic framework(MOF)(Materials of Institut Lavoisier:MIL-100(Fe...Because of its significant toxicological effects on the environment and human health,arsenic(As)is a major global issue.In this study,an Fe-based metal-organic framework(MOF)(Materials of Institut Lavoisier:MIL-100(Fe))which was impregnated with reduced graphene oxide(rGO)by using a simple hydrothermal method and coated with birnessitetype manganese oxide(δ-MnO2)using the one-pot reaction process(MIL-100(Fe)/rGO/δ-MnO2 nanocomposites)was synthesized and applied successfully in As removal.The removal efficiency was rapid,the equilibrium was achieved in 40 min and 120 min for As(Ⅲ)and As(Ⅴ),respectively,at a level of 5 mg/L.The maximum adsorption capacities of As(Ⅲ)and As(Ⅴ)at pH 2 were 192.67 mg/g and 162.07 mg/g,respectively.The adsorbent revealed high stability in pH range 2-9 and saturated adsorbent can be fully regenerated at least five runs.The adsorption process can be described by the pseudo-second-order kinetic model and Langmuir monolayer adsorption.The adsorption mechanisms consisted of electrostatic interaction,oxidation and inner sphere surface complexation.展开更多
Efficient and robust photocatalysts for environmental pollutants removal with outstanding stability have great significance.Herein,we report a kind of three dimensional(3D)photocatalyst presented as Z-scheme heterojun...Efficient and robust photocatalysts for environmental pollutants removal with outstanding stability have great significance.Herein,we report a kind of three dimensional(3D)photocatalyst presented as Z-scheme heterojunction,which combining TiO_(2) and ZnxCd1-xS with graphene aerogel to contrast TiO2-ZnxCd1-xS graphene aerogel(TSGA,x=0.5)through a moderate hydrothermal process.The as-prepared Z-scheme TSGA was used to remove aqueous Cr(VI)via a synergistic effect of adsorption and visible light photocatalysis.The adsorption equilibrium can be reached about 40 min,then after about 30 min irradiation under visible light(wavelength(λ)>420 nm)the removal rate of Cr(VI)almost reached 100%,which is much better than the performance of pristine TiO_(2) and Zn_(0.5)Cd_(0.5)S,as well as TiO2 graphene aerogel(TGA)and Zn0.5Cd0.5S graphene aerogel(SGA).The virulent Cr(VI)was reduced to Cr(III)with hypotoxicity after photocatalysis on TSGA,meanwhile the as-synthesized TSGA presented a good stability and reusability.The reduced graphene oxide(rGO)sheets between TiO_(2) and Zn_(0.5)Cd_(0.5)S played a role as charge transfer mediator,promoting the photoinduced electrons transfer and photocatalysis ability of TSGA was enhanced significantly.Hence,such photocatalyst exhibits a potential application on removing heavy metals with high efficiency and stability from polluted aqueous environment.展开更多
基金supported by the Social Development Fund of Guangdong Province(No.2017A020216018)the Guangzhou Science and Technology Project(No.201904010319)
文摘Because of its significant toxicological effects on the environment and human health,arsenic(As)is a major global issue.In this study,an Fe-based metal-organic framework(MOF)(Materials of Institut Lavoisier:MIL-100(Fe))which was impregnated with reduced graphene oxide(rGO)by using a simple hydrothermal method and coated with birnessitetype manganese oxide(δ-MnO2)using the one-pot reaction process(MIL-100(Fe)/rGO/δ-MnO2 nanocomposites)was synthesized and applied successfully in As removal.The removal efficiency was rapid,the equilibrium was achieved in 40 min and 120 min for As(Ⅲ)and As(Ⅴ),respectively,at a level of 5 mg/L.The maximum adsorption capacities of As(Ⅲ)and As(Ⅴ)at pH 2 were 192.67 mg/g and 162.07 mg/g,respectively.The adsorbent revealed high stability in pH range 2-9 and saturated adsorbent can be fully regenerated at least five runs.The adsorption process can be described by the pseudo-second-order kinetic model and Langmuir monolayer adsorption.The adsorption mechanisms consisted of electrostatic interaction,oxidation and inner sphere surface complexation.
基金supported by the Guangzhou Science and Technology Project (Nos. 201904010319, 202102020131)
文摘Efficient and robust photocatalysts for environmental pollutants removal with outstanding stability have great significance.Herein,we report a kind of three dimensional(3D)photocatalyst presented as Z-scheme heterojunction,which combining TiO_(2) and ZnxCd1-xS with graphene aerogel to contrast TiO2-ZnxCd1-xS graphene aerogel(TSGA,x=0.5)through a moderate hydrothermal process.The as-prepared Z-scheme TSGA was used to remove aqueous Cr(VI)via a synergistic effect of adsorption and visible light photocatalysis.The adsorption equilibrium can be reached about 40 min,then after about 30 min irradiation under visible light(wavelength(λ)>420 nm)the removal rate of Cr(VI)almost reached 100%,which is much better than the performance of pristine TiO_(2) and Zn_(0.5)Cd_(0.5)S,as well as TiO2 graphene aerogel(TGA)and Zn0.5Cd0.5S graphene aerogel(SGA).The virulent Cr(VI)was reduced to Cr(III)with hypotoxicity after photocatalysis on TSGA,meanwhile the as-synthesized TSGA presented a good stability and reusability.The reduced graphene oxide(rGO)sheets between TiO_(2) and Zn_(0.5)Cd_(0.5)S played a role as charge transfer mediator,promoting the photoinduced electrons transfer and photocatalysis ability of TSGA was enhanced significantly.Hence,such photocatalyst exhibits a potential application on removing heavy metals with high efficiency and stability from polluted aqueous environment.
