Ultrasmall Bi nanoparticles confined in carbon nanosheets as highly active and durable catalysts for CO2 electroreduction

[Display omitted] •Binder-free electrode is obtained by a dip coating and calcination two-step method.•Ultrasmall Bi nanoparticles are confined in the in‐situ‐formed carbon nanosheets.•High durability is achieved at a remarkable high current density for nearly 40 h.•The electrode exhibits excellent CO2RR activity in a synergistic way.•PVP-derived carbon nanosheet facilitate interface charge-transfer capability. Developing high-efficient and durable electrocatalysts for CO2 electroreduction reaction (CO2RR) at high current density is attractive but still challenging. In this study, ultrasmall Bi nanoparticles confined in carbon nanosheets are successfully prepared by directly annealing of dipped carbon cloth. Benefited from the uniform distribution of the ultrasmall Bi nanoparticles and the in‐situ‐formed carbon nanosheets, the resultant self-supported electrocatalysts exhibit excellent CO2RR activity in a synergistic way. The optimized Bi-PVP/CC600 exhibits high formate faradaic efficiency of over 81 % at high current densities in a wide potential range. Impressively, high durability is also achieved for this binder-free electrode, with a remarkable high current density of 54 mA∙cm−2 for nearly 40 h. The high performance associated with this facile and potentially scalable synthetic method suggests the great application potential of ultrasmall Bi nanoparticles in CO2RR. The strategy developed herein is versatile and can be extended to prepare other high‐performance ultrasmall metal nanoparticles catalysts.