Photocatalytic degradation of 2-propanol and phenol using Au loaded MnWO4 nanorod under visible light irradiation

Abstract

Single crystalline MnWO4 nanorod has been prepared by low temperature hydrothermal reaction at 180 °C. The prepared MnWO4 possesses band gap of 2.63 eV. Photochemical decomposition method has been followed to disperse Au nanoparticles onto MnWO4 nanorod. The prepared Au loaded MnWO4 nanorod demonstrated greatly enhanced photocatalytic activity in decomposing 2-propanol and evolving CO2 in gas phase and phenol in aqueous phase compared to bare MnWO4 and commercial TiO2 nanoparticles (Degussa P25) under visible light ( = 420 nm) irradiation. The Au loading was optimized to 3.79 wt% for the highest efficiency. The enhanced photocatalytic activity originates from the absorption of visible light by MnWO4 as well as the introduction of nanoparticulate Au on the surface of MnWO4 as cocatalyst to impede the recombination of photogenerated charge-carriers.