Deciphering the Superior Electronic Transmission Induced by the Li-N Ligand Pairs Boosted Photocatalytic Hydrogen Evolution.

Abstract

Atomic level decoration route is designated as one of the attractive methods to regulate both the charge density and band structure of photocatalysts. Moreover, to enable more efficient separation and transport of photocarriers, the construction of novel active sites can enhance both the reactivity and electrical conductivity of the crystal. Herein, an Li-N ligand is constructed via co-doping lithium and nitrogen atoms into ZnIn2 S4 lattice, which achieves a promoted photocatalytic H2 evolution at 9737µmol g-1 h-1 . The existence of Li-N ligand pairs and the behaviors of photocarriers on L40 N5 ZIS are determined systematically, which also provides a unique insight into the mechanism of the improved photocarrier migration rate. With the introduction of Li-N dual sites, the vacancy form of ZnIn2 S4 has changed and the photocatalytic stability is significantly improved. Interestingly, the change of charge density around Li-N ligand in ZnIn2 S4 is determined by theoretical simulations, as well as the regulated energy barrier of photocatalytic water splitting caused by Li-N dual sites, which act as both adsorption site for H2 O and stronger reactive sites. This work helps to extend the understanding of ZnIn2 S4 and offers a fresh perspective for the creation of a Li-N co-doped photocatalyst.