Decoration of Ag nanoparticles on CoMoO4 rods for efficient electrochemical reduction of CO2

Hydrothermal and photoreduction/deposition methods were used to fabricate Ag nanoparticles (NPs) decorated CoMoO 4 rods. Improvement of charge transfer and transportation of ions by making heterostructure was proved by cyclic voltammetry and electrochemical impedance spectroscopy measurements. Linear sweep voltammetry results revealed a fivefold enhancement of current density by fabricating heterostructure. The lowest Tafel slope (112 mV/dec) for heterostructure compared with CoMoO 4 (273 mV/dec) suggested the improvement of electrocatalytic performance. The electrochemical CO 2 reduction reaction was performed on an H-type cell. The CoMoO 4 electrocatalyst possessed the Faraday efficiencies (FEs) of CO and CH 4 up to 56.80% and 19.80%, respectively at − 1.3 V versus RHE. In addition, Ag NPs decorated CoMoO 4 electrocatalyst showed FEs for CO, CH 4 , and C 2 H 6 were 35.30%, 11.40%, and 44.20%, respectively, at the same potential. It is found that CO 2 reduction products shifted from CO/CH 4 to C 2 H 6 when the Ag NPs deposited on the CoMoO 4 electrocatalyst. In addition, it demonstrated excellent electrocatalytic stability after a prolonged 25 h amperometric test at − 1.3 V versus RHE. It can be attributed to a synergistic effect between the Ag NPs and CoMoO 4 rods. This study highlights the cooperation between Ag NPs on CoMoO 4 components and provides new insight into the design of heterostructure as an efficient, stable catalyst towards electrocatalytic reduction of CO 2 to CO, CH 4 , and C 2 H 6 products.