Linker Assisted Composite of MoS 2 and g-C 3 N 5 : Sunlight-driven Efficient Hydrogen Evolution by Photocatalytic Water Splitting

Abstract

A photocatalyst capable of harnessing direct sunlight for producing hydrogen through water splitting is the need of the hour. In this work, this is achieved by depositing hydrothermally prepared MoS2 over APTES-modified, nitrogen-rich graphitic carbon nitride (g-C3N5) to form a heterostructure. This heterojunction composite demonstrates elevated rates of hydrogen evolution through water splitting via both photoelectrochemical and photocatalytic performances. The optimized sample of 5% MoS2/g-C3N5 composite accomplished a photocatalytic hydrogen production of 3553 μmol g -1 under solar simulator and 9554 μmol g -1 when exposed to the direct sunlight for 3 hours. A large cathodic current density (-321 μA cm -2 for 5% MoS2/g-C3N5, at 0.0 V vs. RHE) in Linear Sweep Voltammetry (LSV) and immediate current response in transient current study during photoelectrochemical hydrogen evolution reactions (PEC HER) validate the high efficacy for hydrogen evolution. A significant increase in light absorption, charge separation, and charge carrier migration in the composite accounts for enhancing the photoactivity. The study provides a roadmap for the construction of stable g-C3N5 composites with transition metal chalcogenides for green hydrogen production.