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

A photocatalytic membrane of Bi5O7I/WO3/Ni foam was first prepared by electrophoretic deposition of WO3 and Bi5O7I on Ni foam. The Bi5O7I and WO3 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 Bi5O7I and WO3 promotes carrier separation efficiency of Bi5O7I/WO3, 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.