A novel chemical reaction between P25 and γ-Bi2O3 in CaTiO3 preparation constructing two new transfer channels of charge carriers to boost photocatalytic degradation activity

•A novel chemical reaction between P25 and γ-Bi2O3 occurred in CaTiO3 preparation.•A new crystal phase Bi4Ti3O12 was generated to construct two new transfer channels.•The optimal sample displayed the high photocatalytic efficiency.•The TOC and COD contents also decreased rapidly for light irradiation.•The final degradation products were non-toxic upon Escherichia coli growth.