Microfluidic Synthesis Platform of Silver Nanocubes for Co2 Electroreduction to Co

Abstract

Silver is a prominent material for electrocatalytic CO2 reduction (CO2RR) to CO with high Faradaic efficiency (FE), relatively low price, and huge reserves. Size and structure control of metallic nanomaterials have been confirmed to significantly affect the catalytic performance. For this purpose, a microfluidic synthesis platform is built innovatively to achieve controllable, precise, and continuous preparation of monodisperse silver nanocubes (Ag NCs). Three stages of the growth process for Ag NCs are revealed through online regulation of residence time, and then the formation mechanism is proposed. In addition, density functional theory (DFT) calculations confirm the catalytic role of Ag2S clusters and the synergistic capping effect of Cl- and PVP. Finally, the prepared Ag NCs are applied to CO2RR, achieving 95.6% CO FE at -0.8 VRHE and stable operation for at least 12 h.

Keywords: microfluidic, Silver nanocubes, Growth mechanism, Electrocatalytic CO2 reduction