Cu‐Based MOF/TiO ₂ Composite Nanomaterials for Photocatalytic Hydrogen Generation and the Role of Copper

Abstract The development of active and durable photocatalysts without noble metals for green hydrogen generation is a major challenge in photocatalysis. Herein, composite nanomaterials based on TiO 2 coupled with HKUST‐1, a copper metal–organic framework, for hydrogen generation by photocatalysis using water and methanol as sacrificial agents are developed. To design a highly active composite, the mass ratios between HKUST‐1 and TiO 2 are studied and optimized. The photoactive composite materials are characterized by TEM, UV–vis spectroscopy, FTIR, XRD, XPS, and photoelectrochemical studies. The charge carrier dynamics is also studied by time‐resolved microwave conductivity and the crucial role of the copper is also investigated by XPS and electron paramagnetic resonance. DFT calculations are also used to understand the mechanism involved in H 2 generation. The findings reveal a high hydrogen evolution rate of HKUST‐1/TiO 2 (5.11 mmol g −1 h −1 ) for the first cycle with the mass ratio (1:20). This activity increases with cycling until surpassing the performance of the 1 wt.% Pt (TiO 2 ) material, used as a benchmark and known as a reference in terms of photocatalytic hydrogen production, and a rate of 13.24 mmol g −1 h −1 is obtained after the sixth cycle.