The photocatalytic conversion of biomass into high-value chemicals,coupled with simultaneous hydrogen(H_(2))evolution,leveraging the electrons and holes generated by solar energy,holds great promise for addressing ene...The photocatalytic conversion of biomass into high-value chemicals,coupled with simultaneous hydrogen(H_(2))evolution,leveraging the electrons and holes generated by solar energy,holds great promise for addressing energy demands.In this study,we constructed a dual functional photocatalytic system formed by NiS loaded on Ni doped two-dimensional(2D)CdS nanosheet(NiS/Ni-CdSNS)heterostructure for visible-light-driven H_(2)evolution and ethanol oxidation to acetaldehyde.Remarkably,the 2D NiS/NiCdSNS exhibited significant activity and selectivity in both photocatalytic H_(2)evolution and ethanol oxidation,achieving yields of 7.98 mmol g^(-1)h^(-1)for H_(2)and 7.33 mmol g^(-1)h^(-1)for acetaldehyde.The heterogeneous interface of the composite facilitated efficient charge separation,while NiS provided abundant sites for proton reduction,thereby promoting the overall dual-functional photocatalytic activity.Density functional theory calculations further reveal that both Ni doping and NiS loading can reduce the reaction energy barrier of ethanol oxidation of free radicals,and NiS/Ni-CdSNS composite materials exhibit stronger ethanol C-H activation ability to generate key intermediate·CH(OH)CH_(3)on the surface.This work serves as a valuable guide for the rational design of efficient dual functional photocatalytic systems that combine H_(2)evolution with the selective conversion of organic compounds into high-value chemicals.展开更多
以农林废弃生物质气化合成混合醇工艺为对象,利用混合生命周期评估方法对百吨级系统进行环境影响分析。通过构建系统的工艺模型和收集生命周期资源消耗及排放清单,研究农林业、收储运和制取等各阶段的投入和排放特性,对棉秆、玉米秸秆...以农林废弃生物质气化合成混合醇工艺为对象,利用混合生命周期评估方法对百吨级系统进行环境影响分析。通过构建系统的工艺模型和收集生命周期资源消耗及排放清单,研究农林业、收储运和制取等各阶段的投入和排放特性,对棉秆、玉米秸秆、木屑和枝丫柴4种原料制取系统的环境影响特性进行分析,并与5万吨级系统进行比较。结果表明:百吨级系统生命周期化石能源消耗和温室气体排放分别在589~734 kJ/MJ混合醇和63.2~80.8 g CO_(2)eq/MJ混合醇范围内,制取阶段的电力消耗是最主要的影响因素,其次为系统设备设施投入,玉米秸秆混合醇的环境影响最大,这与原料碳含量低及混合醇收率低有关。展开更多
基金supported by the National Key R&D Program of China(No.2022YFB1903200)the National Natural Science Foundation of China(Nos.U23A2087,22372137,22102136,22072057,22227802,22172126)+2 种基金the Key Research and Development Program of Guangxi(No.GUIKE AB23026116)the Fundamental Research Funds for the Central Universities(Nos.20720220105,20720232005)the XMU Training Program of Innovation and Enterpreneurship for Undergraduates(Nos.2022Y1132,202310384027)。
文摘The photocatalytic conversion of biomass into high-value chemicals,coupled with simultaneous hydrogen(H_(2))evolution,leveraging the electrons and holes generated by solar energy,holds great promise for addressing energy demands.In this study,we constructed a dual functional photocatalytic system formed by NiS loaded on Ni doped two-dimensional(2D)CdS nanosheet(NiS/Ni-CdSNS)heterostructure for visible-light-driven H_(2)evolution and ethanol oxidation to acetaldehyde.Remarkably,the 2D NiS/NiCdSNS exhibited significant activity and selectivity in both photocatalytic H_(2)evolution and ethanol oxidation,achieving yields of 7.98 mmol g^(-1)h^(-1)for H_(2)and 7.33 mmol g^(-1)h^(-1)for acetaldehyde.The heterogeneous interface of the composite facilitated efficient charge separation,while NiS provided abundant sites for proton reduction,thereby promoting the overall dual-functional photocatalytic activity.Density functional theory calculations further reveal that both Ni doping and NiS loading can reduce the reaction energy barrier of ethanol oxidation of free radicals,and NiS/Ni-CdSNS composite materials exhibit stronger ethanol C-H activation ability to generate key intermediate·CH(OH)CH_(3)on the surface.This work serves as a valuable guide for the rational design of efficient dual functional photocatalytic systems that combine H_(2)evolution with the selective conversion of organic compounds into high-value chemicals.
文摘以农林废弃生物质气化合成混合醇工艺为对象,利用混合生命周期评估方法对百吨级系统进行环境影响分析。通过构建系统的工艺模型和收集生命周期资源消耗及排放清单,研究农林业、收储运和制取等各阶段的投入和排放特性,对棉秆、玉米秸秆、木屑和枝丫柴4种原料制取系统的环境影响特性进行分析,并与5万吨级系统进行比较。结果表明:百吨级系统生命周期化石能源消耗和温室气体排放分别在589~734 kJ/MJ混合醇和63.2~80.8 g CO_(2)eq/MJ混合醇范围内,制取阶段的电力消耗是最主要的影响因素,其次为系统设备设施投入,玉米秸秆混合醇的环境影响最大,这与原料碳含量低及混合醇收率低有关。
基金supported by the National Natural Science Foundation of China (50772107)National Key Basic Research Program of China (973)(2007CB210206)National High-Tech Research and Development Program of China (863) (2009AA05Z435)~~
