Oxygen vacancies enhanced photocatalytic activity towards VOCs oxidation over Pt deposited Bi2WO6 under visible light

Pt assisted self-modified Bi2WO6 performed high photocatalytic activity and precious stability for degradation of gaseous toluene. [Display omitted] •0.15% Pt-Bi2WO6 performed high photocatalytic activity on degradation of VOCs.•Gaseous toluene could be mineralized by Pt/Bi-BWO in a short time.•Oxygen vacancy could enhance the production of ROS.•The position of oxygen vacancy and Pt on Bi2WO6(131) was simulated. 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•6H2O. 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 O2 to enhance the production of reactive oxygen species (ROS), such as O2− and OH. 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.