Construction of oxygen vacancy mediated direct Z scheme BiWO/SrTiO hybrid on cellulose fibers for high-performance and recyclable photocatalytic paper.

The O-vacancy BiWO/SrTiO heterojunction photocatalyst with Z scheme photogenerated electron transfer mechanism was loaded on cellulose fibers to construct a visible light-responsive photocatalytic composite paper for efficient and recyclable degradation of organic dyes in water. The introduction of O vacancies in BiWO by alkali etching increased the utilization rate of BiWO for visible light and achieved effective regulation of the energy band structure and Fermi level, which transformed BiWO/SrTiO type-II heterojunction into Z scheme heterojunction. The light-excited electrons in the conduction band of O-vacancy BiWO directly migrated to the valence band of SrTiO, which improved the separation efficiency of photogenerated carriers and maximized the redox capability of semiconductors. Compared with other control papers, O-vacancy BiWO/SrTiO paper exhibited the best photocatalytic performance, and its degradation rate for rhodamine B could reach 71.1% under 100 min of Xe lamp irradiation. The O-vacancy BiWO/SrTiO paper also showed good photocatalytic cycle stability. Loading heterojunction on the cellulose fibers solved the problem of poor reusability and difficult in recovery for powder semiconductor photocatalyst in practical applications. This study provides a novel strategy for constructing Z scheme heterogeneity on cellulose fibers to prepare composite paper with high photocatalytic activity and good reusability.