Concurrent Photocatalytic Hydrogen Generation and Dye Degradation Using MIL‐125‐NH₂ under Visible Light Irradiation

Abstract

Abstract The impact of different transition metal‐based co‐catalysts toward photocatalytic water reduction when they are physically mixed with visible‐light active MIL‐125‐NH 2 is first systematically studied. All co‐catalyst/MIL‐125‐NH 2 photocatalytic systems are found to be highly stable after photocatalysis, with the NiO/MIL‐125‐NH 2 and Ni 2 P/MIL‐125‐NH 2 systems exhibiting high hydrogen (H 2 ) evolution rates of 1084 and 1230 µmol h −1 g −1 , respectively. Second, how different electron donors affect the stability and H 2 generation rate of the best Ni 2 P/MIL‐125‐NH 2 system is investigated and it is found that triethylamine fulfils both requirements. Then, the electron donor is replaced with rhodamine B (RhB), a dye that is commonly used as a simulant organic pollutant, with the aim of integrating the photocatalytic H 2 generation with the degradation of RhB in a single process. This is of supreme importance as replacing the costly (and toxic) electron donors with hazardous molecules present in wastewater makes it possible to oxidize organic pollutants and produce H 2 simultaneously. This is the first study where a metal–organic framework (MOF) system is used for this dual‐photocatalytic activity under visible light illumination and the proof‐of‐concept approach envisions a sustainable waste‐water remediation process driven by the abundant solar energy, while H 2 is produced, captured, and further utilized.