Toward Inexpensive Photocatalytic Hydrogen Evolution: A Nickel Sulfide Catalyst Supported on a High-Stability Metal–Organic Framework

Few-atom clusters composed of nickel and sulfur have been successfully installed into the Zr­(IV)-based metal–organic framework (MOF) NU-1000 via ALD-like chemistry (ALD = atomic layer deposition). X-ray photoelectron spectroscopy and Raman spectroscopy are used to determine that primarily Ni²⁺ and S^2– sites are deposited within the MOF. In a pH 7 buffered aqueous solution, the porous catalyst is able to produce H₂ gas at a rate of 3.1 mmol g^–1 h^–1 upon UV irradiation, whereas no H₂ is generated by irradiating bare NU-1000. Upon visible light irradiation, little H₂ generation was observed; however, with the addition of an organic dye, rose bengal, NiS-AIM can catalyze the production of H₂ at an enhanced rate of 4.8 mmol g^–1 h^–1. These results indicate that ALD in MOFs (AIM) can engender reactivity within high surface area supports for applications in the solar fuels field