Orthogonal Charge Transfer by Precise Positioning of Silver Single Atoms and Clusters on Carbon Nitride for Efficient Piezocatalytic Pure Water Splitting.

Abstract

Developing efficient piezocatalytic systems for two-electron water splitting (TEWS) with producing H2 and H2 O2 shows great promise to meet the industrial demand. Herein, Ag single atoms (SAs) and clusters are co-anchored on carbon nitride (AgSA+C -CN) to serve as the multifunctional sites for efficient TEWS. The Ag SAs enhance the in-plane piezoelectric polarization of CN that is intimately modulated by the atomic coordination induced charge redistribution, and Ag clusters afford strong interfacial electric field to remarkably promote the out-of-plane migration of piezoelectrons from CN. Moreover, AgSA+C -CN yields a larger piezoresistive effect that elevates carrier mobility under strain. Consequently, a superior H2 and H2 O2 evolution rate of 7.90 mmol g-1 h-1 and 5.84 mmol g-1 h-1 is delivered by AgSA+C -CN, respectively, far exceeding that of the previously reported piezocatalysts. This work not only presents the SAs decoration as an available polarization enhancement strategy, but also sheds light on the superiority of multi-sites engineering in piezocatalysis.