(001)-TiO2 nanosheets loaded on BiOI improve carrier separation and enhance the photocatalytic activity

(001)-TiO2/BiOI photocatalysts with microsphere morphology were synthesized by a solvothermal method. The (001)-TiO2/BiOI demonstrated highest photocatalytic performance for the RhB degradation rate of 0.049 min−1 under visible light, which is 5 and 7 times that of (001)-TiO2 and BiOI, respectively. The increased photocatalytic efficiency is due to the construction of heterojunctions, which promote the transportation of photo-generated carriers. The good photochemical stability of the prepared photocatalysts was demonstrated by cycling experiments. The radical quenching experiments show that ·O2− and ·OH are the principal active species in the photocatalytic reaction mechanism. Finally, a possible mechanism of p–n heterojunctions in the photocatalytic reaction process was proposed.