Beijing Key Laboratory of Bioprocess, Beijing Advanced Innovation Center for Soft Matter Science and Engineering (BAIC-SM), Beijing University of Chemical Technology;
Yilin Zhao;Yaoqiang Wang;Gang Xiao;Haijia Su;
Trace environmental pollutants have become a serious problem with special attention on the hazardous heavy metals, refractory organics, and pathogenic microorganisms. With coupling biosorption and photocatalysis to develop biomaterial/TiO_2 composite photocatalysts is a promising method to remove these trace pollutants because of the synergistic effect. Biomaterials provide multiple function groups which can selectively and efficiently enrich trace pollutants onto the surface of the photocatalysts, thus facilitating the following transformation mediated by TiO_2 photocatalysis. Biomaterials can also help the dispersion and recovery of TiO_2, or even modify the band structure of TiO_2. The fabrication of chitosan/TiO_2, cellulose/TiO_2, as well as other biomaterial/TiO_2 composite photocatalysts is discussed in detail in this review. The application significance of these composite photocatalysts for the selective removal of trace pollutants is also addressed. Several problems should be solved before the realistic applications can be achieved as discussed in the final section.