Achieving convenient CO2 electroreduction and photovoltage in tandem using potential-insensitive disordered Ag nanoparticles

Abstract

Photovoltaic-electrochemical (PV-EC) systems can not only make full use of solar energy, but also transform CO₂ into organic molecules. However, it is difficult to achieve PV-EC systems since most CO₂ reduction catalysts are potential-dependent. This paper describes the rational design of potential-insensitive disordered Ag, which can achieve more than 90% faradaic efficiency (FE) for CO within a wide voltage range of 1.1 V in an electroreduction CO₂ system. The system shows attractive activity under different photovoltage conditions in a PV-EC system. By employing in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS), we address the origin of the volcano peak of FE on Ag nanoclusters to understand the mechanism of the carbon dioxide reduction reaction (CO₂RR). In addition, we find that the CO₂RR on disordered Ag nanoparticles is a proton–electron coupling transfer (PECT) reaction mechanism, which may result in high activity in a wide potential range.