Zr-based MOF: An enhanced photocatalytic application towards H2 evolution by consequence of functional group and LSPR effect

Abstract

In current scenario photocatalytic water splitting towards H2 evolution by heterogeneous photocatalysis is an emerging science for accepting the future global energy crisis in modern life. In this regard we have synthesized and modified Zr-based MOF i.e. UiO-66, UiO-66-NH2 and Au/UiO-66-NH2 by hydrothermal method and tested its efficiency towards H2 evolution. The synthesized photocatalyst were well characterized by XRD, FTIR, UV–Vis and Electrochemical analysis to determine their structural and electro chemical properties. The analysis result confirms the successful synthesis of these photocatalyst and reveals the enhanced photo catalytic efficiency of Au/UiO-66-NH2. The rate of H2 evolution was observed in the order Au/UiO-66-NH2 > UiO-66-NH2 > UiO-66. This can be attributed to the strong LSPR effect of noble metal Au and the enhanced visible light absorption capacity of linker due to the presence of –NH2 group. The Au nanoparticles acts as an electron collector from the conduction band of photo excited UiO-66-NH2 and hence inhibits the first recombination of electron-hole pairs. The photogenerated electrons accumulated on Au surface readily facilitate H2 production by reduction of H2O molecule. The maximum H2 evolution observed for Au/UiO-66-NH2 was 387 µmol/h. The observed photocatalytic performance of H2 evolution will provide an advantageous blue print for the fabrication of noble metals on MOF surface towards the future photocatalytic applications.