Chloroplast-like porous bismuth-based core-shell structure for high energy efficiency CO electroreduction.

Electrochemical CO reduction reaction (CORR) to formate is economically viable considering the energy input and market value. Through learning nature, a series of chloroplast-like porous bismuth-based core-shell (CPBC) materials have been designed. In these materials, the porous carbon can enrich and transfer CO to the core-shell Bi@BiO in CO reduction process, during which BiO layer can be transformed into activated metastable layer to efficiently convert CO into formate and Bi can provide abundant electrons. Based on this, superior performances for most of important parameters in CORR can be achieved and best of them, CPBC-1 presents remarkable Faradaic efficiency (FE > 94%) over a wide potential range (-0.65 to -1.0 V) with high catalysis durability (>72 h). Noteworthy, its maximum energy efficiency is as high as 76.7% at -0.7 V, the highest one in reported bismuth-based materials. This work opens novel perspectives in designing nature-inspired CORR electrocatalysts.