Abstract
Artificial photosynthesis provides an efficient strategy for solar energy storage via water splitting and CO(2) reduction, but it remains a challenge in tuning artificial photosynthesis between these two competing reactions. Herein, we demonstrate photoinduced conversion of monometallic to bimetallic sites in a Fe-Co nitroprusside (FeCo-NP) to steer the reaction path from H(2) evolution to CO(2) reduction. Monometallic Co sites achieve efficient H(2) production with 28.5 mmol g(-1) activity and 85.4% selectivity. Photoinduced release of nitrosyl groups from Fe sites generates bimetallic Fe-Co sites, which suppress H(2) evolution and enhance CO(2) reduction, yielding 31.5 mmol g(-1) activity and 87.3% selectivity for C1 products. Mechanistic investigations reveal that monometallic Co sites catalyze H(2) evolution via H(2)O adsorption and O-H cleavage while bimetallic Fe-Co sites facilitate both H(2)O and CO(2) adsorption and subsequent O and C hydrogenation for CO and HCOOH. This work uncovers a strategy to manipulate competing reaction pathways via photoinduced conversion of monometallic to bimetallic sites, which provides unique insights into addressing environmental issues and energy crises.