In Situ Generation of Flash Graphene Supported Spherical Bismuth Nanoparticles in Less than 200 ms for Highly Selective Carbon Dioxide Electroreduction

Flash Joule heating (FJH) method is an emerging and powerful technique that has exhibited great potential in various domains. Herein, we successfully prepared flash graphene (FG)-supported Bi nanoparticles (Bi-NPs/FG) via the ultrafast and ecofriendly FJH method in less than 200 ms for the first time. Benefited from the synergistic effect of highly conductive FG and active Bi nanocrystals, the Bi-NPs/FG hybrid shows a highly selective CO2 electroreduction with an ultrahigh Faradaic efficiency of 93.8% toward C1 product (i.e., formate). Furthermore, the findings from Density Functional Theory (DFT) calculations unveil that the reconstruction process not only enhances the bonding strength of the surface Bi-OCHO*, but also optimizes the adsorption energy of the key intermediate (OCHO*), thus benefiting the production of formate. In addition, we conducted an extension study of the FJH route to demonstrate its versatility in preparing a range of other metal/alloy NPs encased in FG. This work presents a feasible pathway to the superfast and massive production of highly efficient electrocatalyst for CO2 conversion, and it can be extended to other application scenarios with great potential.