WATER DISPERSIBLE CSPBBR3 PEROVSKITE NANOCRYSTALS WITH ULTRA STABILITY AND ITS APPLICATION IN ELECTROCHEMICAL CO2 REDUCTION

Abstract

Thanks to the excellent optoelectronic properties, lead halide perovskites (LHPs) have been widely employed in highperformance optoelectronic devices such as solar cells and lightemitting diodes. However, overcoming their poor stability against water has been one of the biggest challenges for most applications. Herein, we report a novel hot-injection method in a Pb-poor envi‑ ronment combined with a well-designed purifcation process to synthesize water-dispersible CsPbBr3 nanocrystals (NCs). The as-prepared NCs sustain their superior photoluminescence (91% quantum yield in water) for more than 200 days in an aqueous environment, which is attributed to a passivation efect induced by excess CsBr salts. Thanks to the ultra-stability of these LHP NCs, for the frst time, we report a new application of LHP NCs, in which they are applied to electrocatalysis of CO2 reduction reac‑ tion. Noticeably, they show signifcant electrocatalytic activity (faradaic yield: 32% for CH4, 40% for CO) and operation stability (>350 h).