SiO₂/Bi₂MoO₆ nanocomposites with high photocatalytic activity under visible light irradiation

Highlights: • The SiO₂/Bi₂MoO₆ composite photocatalysts were synthesized. • SiO₂/Bi₂MoO₆ showed better photocatalytic performance than pure SiO₂ and Bi₂MoO₆. • The photocatalytic mechanism of SiO₂/Bi₂MoO₆ composite was also proposed. - Abstract: The effect of SiO₂ nanoparticles on Bi₂MoO₆ photocatalytic performance was described. The results indicated that SiO₂ nanospheres were dispersed on Bi₂MoO₆ nanosheets to form heterostructures with higher specific surface area and more intensive absorption within the visible light range in comparison with pure Bi₂MoO₆. These excellent structural and spectral properties endowed the SiO₂–Bi₂MoO₆ composites with enhanced photocatalytic activities. The photocatalytic results for the degradation of Rhodamine B (Rh B) indicated that the most active composite proportion is 13.4%SiO₂–Bi₂MoO₆. The high visible light photocatalytic performance was attributed to the synergistic effect between SiO₂ and Bi₂MoO₆, intensive absorption within the visible light range, and high specific surface area. It was also found that the photodegradation of Rh B molecules is mainly attributed to the oxidation action of the generated O₂·⁻ radicals and partly to the action of h_vb⁺ through direct hole oxidation process