Electrochemical reduction of carbon dioxide(CO2ER)into formate plays a crucial role in CO2 conversion and utilization.However,it still faces the problems of high overpotential and poor catalytic stability.Herein,we report a hybrid CO2ER electrocatalyst composed of layered bismuth sulfide(Bi2S3)and bis-muth oxide(Bi2O3)supported on carrageenan derived carbon(Bi-CDC)prepared by a combined pyrolysis with hydrothermal treatment.In such 3D hybrid,layered Bi2O3 and Bi2S3 are uniformly grown on nanocarbon supports.Benefiting from strong synergistic effect between Bi2O3/Bi2S3 and nanocarbon,Bi-CDC-1:2 displays a high Faradic efficiency(FE)of＞80％for formate production in the range of-0.9 V to-1.1 V with the maximum formate FE of 85.6％and current density of 14.1 mA·cm-2 at-1.0 V.Further,a positive onset potential of-0.5 V,a low Tafel slope of 112.38 mV.dec-1,and a slight performance loss during long-term CO2ER tests are observed on Bi-CDC-1∶2.Experimental results shows that the better CO2ER performance of Bi-CDC-1∶2 than that of Bi2O3 can be attributed to the strong inter-facial interactions between nanocarbons and Bi2O3/Bi2S3.In situ ATR-FTIR measurements reveal that the rate-determining step in the CO2ER is the formation of HCOO* intermediated.Compared with carbon sup-port,Bi-CDC-1∶2 can promote the production of HCOO* intermediate and thus promoting CO2ER kinetic.

Key Laboratory of Biomass Chemical Engineering of Ministry of Education,College of Chemical and Biological Engineering,Zhejiang University,Hangzhou 310027,China;Department of Material Chemistry,Nanchang Hangkong University,Nanchang 330063,China;Institute of Zhejiang University-Quzhou,Quzhou 324000,China;School of Biological and Chemical Engineering,Ningbo Technology University,Ningbo 315100,China

[1]Xiangzhao Hu;Junjie Sun;Wanzhen Zheng;Sixing Zheng;Yu Xie;Xiang Gao;Bin Yang;Zhongjian Li;Lecheng Lei;Yang Hou-.Layered bismuth oxide/bismuth sulfide supported on carrageenan derived carbon for efficient carbon dioxide electroreduction to formate)[J].中国化学工程学报（英文版）,2022(03):116-123

muth,nanocarbons

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