Type-II heterojunction of Bi5O7I/WO3 anchored on Ni foam towards efficient photocatalytic degradation of VOCs

Abstract

A photocatalytic membrane of Bi 5 O 7 I/WO 3 /Ni foam was first prepared by electrophoretic deposition of WO 3 and Bi 5 O 7 I on Ni foam. The Bi 5 O 7 I and WO 3 with mass ratio of 6:7 loaded on Ni foam (BWN-6/7) represented excellent photocatalytic performances. Approximately 95.2% of gaseous toluene (2000 mg m -3 ) was degraded over BWN-6/7 after the adsorption for 30 min and the light irradiation for 180 min. The BWN-6/7 could still degrade 81.6% of gaseous toluene after it was used for 4 rounds. Type-Ⅱ transfer pathway of charge between Bi 5 O 7 I and WO 3 promotes carrier separation efficiency of Bi 5 O 7 I/WO 3 , which is further boosted by Ni foam due to its excellent electricity conductivity. The photo-induced species such as h + and ∙OH play curial roles in the degradation of gaseous toluene. • An efficient photocatalytic film of Bi 5 O 7 I/WO 3 /Ni foam for toluene degradation is fabricated. • Type-Ⅱ transfer pathway of carriers between Bi 5 O 7 I and WO 3 is determined by self-designed experimental device. • DFT calculations predict the electrons flow direction between Bi 5 O 7 I/WO 3 and Ni foam. • Photocatalytic degradation mechanism of toluene over Bi 5 O 7 I/WO 3 /Ni foam is proposed.