Embedding Sulfur Atoms in Decahedron Bismuth Vanadate Crystals with a Soft Chemical Approach for Expanding the Light Absorption Range

摘要

Bandgap engineering of semiconductors attracts great attention in the field of photocatalysis to enhance the conversion efficiency of semiconductors. Introducing impurity atoms, such as nitrogen, sulfur and metal atoms, into the crystal lattice of semiconductors is one of the commonly used methods to broaden the light absorption range. However, traditional methods to embed impurity atoms require harsh conditions like high temperatures, which will destroy the morphology-tailored structure of semiconductors in many cases. Herein, we demonstrated a soft chemical approach, hydrothermal method, to expand the light absorption range by introducing sulfur atoms in the typical semiconductor bismuth vanadate (BiVO4). After embedding sulfur atoms, the light absorption edge of BiVO4 crystals can be expanded from 530 nm to more than 650 nm, while, the decahedron morphology with exposed {010} and {110} facets of BiVO4 crystals was still well-maintained. The sulfur-embedded BiVO4 crystals show photocurrent response even under longer wavelengths than 550 nm and also exhibit an evident enhancement than pristine BiVO4 in photoelectrochemical performances under visible light. Our work offers a strategy for manipulating the band structures of semiconductors for applications in solar energy conversion.