Interfacial engineering of bismuth with reduced graphene oxide hybrid for improving CO2 electroreduction performance

In this paper, we report a bismuth and reduced graphene oxide (rGO) hybrid composite (Bi-rGO) via a facile co-reduction method. Compared with the pure Bi, the Bi-rGO hybrid exhibited an enhanced activity and selectivity for CO2 reduction to formate. The maximum faradaic efficiency for formate generation over Bi-rGO hybrid was observed reaching as high as 98% at a relatively low potential of −0.85 V (vs. RHE), which was superior to that of pure Bi (59.8%, −0.85 V). The electrochemical analysis and microscopic characterization reveal that the Bi-rGO hybrid not only generates abundant active sites for enhancing the catalytic activity, but also presents strong electron affinity from the electronic coupling interaction effect to stabilize the main intermediate CO2•− for improving the catalytic selectivity. Impressively, the existence of CO2•− was verified by in-situ ultraviolet absorption spectroscopy during CO2 reduction reaction process. This work may shed light on the electronic coupling interaction effect on CO2 reduction reaction and provide an effective strategy to improve the catalytic performance.