Insights into the photocatalytic performance of Bi 2 O 2 CO 3 /BiVO 4 heterostructures prepared by one-step hydrothermal method.

This paper describes the synthesis of Bi 2 O 2 CO 3 /BiVO 4 heterostructures through a one-step method based on the difference in solubility between two semiconductors that possess a metal in common. The as-synthesized Bi 2 O 2 CO 3 /BiVO 4 heterostructures were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), Raman spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N 2 physisorption, X-ray photoelectron spectroscopy (XPS) and time resolved photoluminescence spectroscopy (TRPL). The role of the heterojunction formed was evaluated by methylene blue (MB) dye and amiloride photodegradation. The formation of the heterostructure was observed indirectly by the great increase in the thermal stability of the Bi 2 O 2 CO 3 phase when compared to its pure phase. The amount of heterojunctions formed between the Bi 2 O 2 CO 3 and BiVO 4 was tuned by vanadium precursor concentration. The proposed strategy was efficient for obtaining Bi 2 O 2 CO 3 /BiVO 4 heterostructures with enhanced photocatalytic performance when compared to their isolated phases, MB and amiloride photodegradation occurred mainly by the action of ˙OH radicals, i.e. by an indirect mechanism. Based on TRPL spectroscopy and VB-XPS results, an enhancement of photoactivity related to an increase in the spatial separation of photo-generated electron/hole pairs was observed due to the formation of a type-II heterostructure.