Efficient Photocatalytic Nitrogen Fixation: Enhanced Polarization, Activation, and Cleavage by Asymmetrical Electron Donation to NN Bond

Abstract

Abstract Photocatalytic nitrogen (N 2 ) fixation suffers from low efficiency due to the difficult activation of the strongly nonpolar NN bond. In this study, a Ru–Co bimetal center is constructed at the interface of Ru/CoS x with S‐vacancy on graphitic carbon nitride nanosheets (Ru‐Vs‐CoS/CN). Upon adsorption, the two N atoms in N 2 are bridged to the Ru–Co center, and the asymmetrical electron donation from Ru and Co atoms to N 2 adsorbate highly polarized NN bond to double bond order. The plasmonic electric‐field‐enhancement effect enables the Ru/CoS x interface to boost the generation of energetic electrons. The Schottky barrier between Ru and CoS x endows the interface with electron transfer from CoS x to Ru. The Ru‐end bound N at the Ru–Co center is preferentially hydrogenated. As a result, the Ru‐Vs‐CoS/CN photocatalyst shows an NH 3 production rate of up to 0.438 mmol g −1 h −1 , reaching a high apparent quantum efficiency of 1.28% at 400 nm and solar‐to‐ammonia efficiency of 0.042% in pure water under AM1.5G light irradiation.