Controlled synthesis of 2D–2D conductive metal–organic framework/g-C3N4 heterojunctions for efficient photocatalytic hydrogen evolution

Abstract

Designing photocatalysts with efficient charge separation and electron transport capabilities to achieve efficient visible-driven hydrogen production remains a challenge. Herein, 2D–2D conductive metal–organic framework/g-C₃N₄ heterojunctions were successfully prepared by an in situ assembly. Compared to pristine g-C₃N₄, the ratio-optimized Ni-CAT-1/g-C₃N₄ exhibits approximately 3.6 times higher visible-light H₂ production activity, reaching 14 mmol g⁻¹. Through investigations using time-resolved photoluminescence, surface photovoltage, and wavelength-dependent photocurrent action spectroscopies, it is determined that the improved photocatalytic performance is attributed to enhanced charge transfer and separation, specifically the efficient transfer of excited high-energy-level electrons from g-C₃N₄ to Ni-CAT in the heterojunctions. Furthermore, the high electrical conductivity of Ni-CAT enables rapid electron transport, contributing to the overall enhanced performance. This work provides a feasible strategy to construct efficient dimension-matched g-C₃N₄-based heterojunction photocatalysts with high-efficiency charge separation for solar-driven H₂ production.