Controlled synthesis of 2D-2D conductive metal-organic framework/g-C 3 N 4 heterojunctions for efficient photocatalytic hydrogen evolution.

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-C 3 N 4 heterojunctions were successfully prepared by an in situ assembly. Compared to pristine g-C 3 N 4 , the ratio-optimized Ni-CAT-1/g-C 3 N 4 exhibits approximately 3.6 times higher visible-light H 2 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-C 3 N 4 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-C 3 N 4 -based heterojunction photocatalysts with high-efficiency charge separation for solar-driven H 2 production.