Core-shell structure of reduced graphene oxide@Ag–TiO2 for photocatalytic H2O splitting and CH3OH dehydrogenation under UV light irradiation

Abstract

The H2 production from water-splitting and dehydrogenation of waste alcohols is widely investigated in current years to find out greener, and more efficient photocatalyst materials. Reduced graphene oxide (rGO; 1-10 wt%) coated TiO2 and Ag(1 wt%)-TiO2 core-shell nanocomposites are fabricated for enhanced photocatalytic H2 production from H2O-splitting and CH3OH-dehydrogenation under UV irradiation. These rGO@TiO2 and rGO@Ag–TiO2 catalysts are characterized by XRD, Raman, FE-SEM, HR-TEM, XPS, BET, CV, EDS-mapping, PL, and UV–vis DRS for morphological, structural, and optical properties. After rGO(1-3 wt%) coating over TiO2, the H2 amount is increased from 5 to 14 mmol for H2O-splitting and 13–83 mmol via CH3OH-dehydrogenation during 5 h UV irradiation, respectively. Due to the synergetic effect of rGO and Ag, core-shell rGO(2-4 wt%) coated Ag–TiO2 produced the highest amount of 108–133 mmol of H2 from water-splitting and 440–450 mmol from CH3OH-dehydrogenation during 7 and 5 h UV irradiation, respectively. The work illustrates the potential of Ag-deposition and rGO-coating over TiO2 for efficient H2 production.