Oxygen Vacancies Enhanced Photocatalytic Activity Towards Vocs Oxidation Over Pt Deposited Bi2wo6 Under Visible Light

A novel Pt assisted self-modified Bi2WO6 composites (Pt/Bi-BWO) with high oxygen vacancies concentration was successfully fabricated via a simple in-situ NaBH4 reduction method in presence of H2PtCl6 center dot 6H(2)O. The Pt/Bi-BWO performed excellent photocatalytic activity on the degradation of gaseous toluene under visible light illumination. The photocatalytic reaction rate of 0.15% Pt/Bi-BWO was 2.88 times higher than that of Bi2WO6. Over 90% gas phase toluene was removed by 0.15% Pt/Bi-BWO in one hour and over 80% of which was degraded into CO2 and H2O. The Pt/Bi-BWO also performed great stability confirmed by circulating runs test. The mechanism of the promotion was explored by electron paramagnetic resonance (EPR) and DFT calculations. The produced oxygen vacancies were below conduction band (CB) of Bi2WO6, leading to a narrowed band gap. Meantime, the generated oxygen vacancies could activate O-2 to enhance the production of reactive oxygen species (ROS), such as O-center dot(2)- and (OH)-O-center dot. In addition, the added Pt could act as electron trap to suppress the recombination of electrons-holes pairs. In a word, this work produced a novel simply made photocatalyst to remove volatile organic compounds.