Graphene quantum dot sensitized leaf-like InVO4/BiVO4 nanostructure: a novel ternary heterostructured QD-RGO/InVO4/BiVO4 composite with enhanced visible-light photocatalytic activity

Abstract

Leaf-like InVO₄/BiVO₄ nanostructures with sizes of 2–5 μm were synthesized by a simple hydrothermal method. Graphene quantum dots (QD-RGO) were then deposited onto the surfaces of the leaf-like InVO₄/BiVO₄ crystals through a facile deposition–precipitation technique. Under visible light irradiation (λ > 420 nm), the QD-RGO/InVO₄/BiVO₄ photocatalyst degraded rhodamine B (Rh B) efficiently and displayed a much higher photocatalytic activity than pure BiVO₄, InVO₄, RGO/InVO₄, RGO/BiVO₄ or an InVO₄/BiVO₄ hybrid. The InVO₄/BiVO₄ photocatalyst with 3 wt% of QD-RGO exhibited the highest photocatalytic efficiency. The quenching effects of different scavengers demonstrated that O₂˙⁻ played a major role in Rh B degradation. It was elucidated that the excellent photocatalytic activity of QD-RGO/InVO₄/BiVO₄ for the degradation of Rh B under visible light (λ > 420 nm) can be ascribed to the extended absorption in the visible light region resulting from the QD-RGO loading, the high specific surface area, and the efficient separation of photogenerated electrons and holes through the QD-RGO/InVO₄/BiVO₄ heterostructure.