Surface Engineering of 2D Metal‐Porphyrin Metal–Organic Frameworks Z‐Scheme Heterostructure for Boosting and Stable Photocatalytic Hydrogen Evolution

Abstract How to improve the stability and activity of metal–organic frameworks is an attractive but challenging task in energy conversion and pollutant degradation of metal–organic frameworks materials. In this paper, we developed a facile method by fabricating TiO ₂ nanoparticles (NPs) layer on 2D copper tetracarboxylphenyl‐metalloporphyrin metal–organic frameworks (MOFs) with Zn2+ as the linkers (ZnTCuMT‐X, “Zn” represented Zn2+ as the linkers, the first “T” represented tetracarboxylphenyl‐metalloporphyrin (TCPP), “Cu” represented the Cu2+ coordinated into the porphyrin macrocycle, “M” represented MOFs, the second “T” represented TiO ₂ NPs layer, and “X” represented the added volume of n‐tetrabutyl titanate (X = 100, 200, 300 or 400)). It was found that the optimized ZnTCuMT‐200 showed greatly and stably enhanced H2 generation, which was about 28.2 times and 47.0 times as high as those of the original metalloporphyrin MOFs and TiO ₂ , respectively. Combined with the results of free radical capture, X‐ray photoelectron spectra, electron spin resonance and theoretical calculation, a direct Z‐scheme electron transfer mechanism was achieved to fully explain the enhanced photocatalytic performance. It demonstrates that facilely designing Z‐scheme heterostructures based on porphyrin MOFs modified with inorganic semiconductor layer could be an advantageous strategy for enhancing the stability and activity of photocatalytic hydrogen evolution.