Facile Fabrication of Highly Efficient Photoelectrocatalysts M x O y @NH 2 ‐MIL‐125(Ti) for Enhanced Hydrogen Evolution Reaction

Abstract Highly efficient amine functionalized M x O y @NH 2 ‐MIL‐125(Ti) (M x O y =MnO 2 , Fe 2 O 3 , Co 3 O 4 , NiO, CuO and ZnO) photoelectrocatalysts have been synthesized by using a simple and cost effective synthetic approach through in‐situ incorporation of pre‐synthesized metal oxide nanoparticles into NH 2 ‐MIL‐125(Ti) MOF via hydrothermal method. All the synthesized samples have been characterized by Powder X‐ray Diffraction, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Energy Dispersive X‐ray Spectrometry, Elemental Mapping, UV‐Vis Spectroscopy and N 2 ‐adsorption isotherm. It has been found that incorporation of nanoparticles into porous MOF decreased the band gap, reduced the electron‐hole pair recombination and enhanced the efficient absorption of visible light. Hydrogen evolution reaction is evaluated by Cyclic voltammetry and linear sweep voltammetry studies at 100 mV/s and 1 mV/s, respectively. Amongst various synthesized samples, CuO@NH 2 ‐MIL‐125(Ti) required lowest overpotential of 146 mV to achieve −5mAcm −2 current density as compared to 226 mV for bare NH 2 ‐MIL‐125(Ti). Moreover, M x O y @NH 2 ‐MIL‐125(Ti) samples showed lower onset potential for hydrogen evolution reaction as compared to bare NH 2 ‐MIL‐125(Ti). Chronoamperometric measurements of all these samples showed their stability for 600 seconds at constant applied voltage of 1.5 V.