Decorating graphdiyne on ultrathin bismuth subcarbonate nanosheets to promote CO2 electroreduction to formate

Electrocatalytic reduction of CO2 is one of the most attractive approaches for converting CO2 into valuable chemical feedstocks and fuels. This work reports a catalyst comprising graphdiyne-decorated bismuth subcarbonate (denoted as BOC@GDY) for efficient electroreduction of CO2 to formate. The BOC@GDY shows a stable current density of 200 mA cm(-2) at -1.1 V in a flow cell configuration, with a faradaic efficiency of 93.5% for formate. Experimental results show that the synergistic effect in BOC@GDY is beneficial for the CO2 adsorption affinity, the reaction kinetics and the selectivity for formate. In addition, in-situ X-ray absorption and Raman spectroscopy indicate that the electron-rich GDY could facilitate the reduction from Bi(III) to Bi(0), thus leading to more active sites. We also demonstrate that the promoting effect of GDY in CO2 electroreduction can be further extended to other metal catalysts. To the best of our knowledge, such general promoting functions of GDY for CO2 electroreduction have not been documented thus far. (C) 2021 Science China Press. Published by Elsevier B.V. and Science China Press. All rights reserved.