Interface engineering of a 2D-C₃N₄/NiFe-LDH heterostructure for highly efficient photocatalytic hydrogen evolution

Abstract

Photocatalytic water splitting offers an economic and sustainable pathway for producing hydrogen as a zero-emission fuel, but it still suffers from low efficiencies limited by visible-light absorption capacity and charge separation kinetics. Herein, we report an interface-engineered 2D-C₃N₄/NiFe layered double hydroxide (CN/LDH) heterostructure that shows highly enhanced photocatalytic hydrogen evolution reaction (HER) rate with excellent long-term stability. The morphology and band gap structure of NiFe-LDH are precisely regulated by employing NH4F as a structure-directing agent, which enables a fine interfacial tuning via coupling with 2D-C₃N₄. The formation of a type II interface in CN/LDH enlarges the active surface area and promotes the charge separation efficiency, leading to an HER rate of 3087 μmol g-1 h-1, which is 14 times higher than that of 2D-C₃N₄. This study highlights a rational interface engineering strategy for the formation of a heterostructure with a proper hole transport co-catalyst for designing effective water-splitting photocatalysts.