Rapid and scalable synthesis of bismuth dendrites on copper mesh as a high-performance cathode for electroreduction of CO2 to formate

Bi-based electrode is believed to be one of the promising cathodes for the electroreduction of CO2 to formate. However, it suffers from energy- and/or time-consuming preparation process and mass transfer limitation of the reactants. Here, we fabricated a novel networked Bi-based electrode by formed in situ from Bi dendrites integrated into a Cu mesh substrate via a facile replacement reaction with energy and time savings. The as-prepared electrode was directly used as a cathode for electroreduction of CO2 to formate without further treatment. It exhibits a formate Faraday efficiency of approximate to 100 %. Additionally, partial current density for formate is as high as 68.51 +/- 4.04 mA cm(-2). This performance outperforms other results obtained on Bi-based electrodes-even most gas-diffusion electrodes under similar conditions. The excellent performance seen here is most likely attributed to its large surface area and fast transport of the reactants. This originates from the Bi dendrites catalysts and the unique network structure of the Cu mesh substrate. This work offers a facile route to obtain an efficient and robust electrode for electroreduction of CO2 to formate, which makes it easy to scale up in industrial applications.