Semiconductive Copper(I)–Organic Frameworks for Efficient Light-Driven Hydrogen Generation Without Additional Photosensitizers and Cocatalysts

The rational design of completely cocatalyst-free and self-sensitized photocatalytic systems for splitting water into hydrogen is a subject of new research. As the first example without additional cocatalysts and photosensitizers, the comparatively cost-effective Cu2I2-based MOF Cu-I-bpy, exhibited a high-efficiently photocatalytic hydrogen production (7.09 mmol·g-1·h-1). DFT calculations established the electronic structures of Cu-I-bpy with a narrow band gap of 2.05 eV, indicating its semi-conductive behavior, which was well consistent with the experimental value of 2.00 eV. The proposed mechanism demonstrates that Cu2I2 clusters of Cu-I-bpy serve as photoelectron generators to accelerate the copper(I) hydrides interaction, providing redox reaction sites for hydrogen evolution. The highly stable cocatalyst-free and self-sensitized Cu-I-bpy provides new insights into the design of cost-effective d10-based MOFs for high-efficient and long-term solar fuels production in future.