Synthesis of BiVO4 nanoparticles with tunable oxygen vacancy level: The phenomena and mechanism for their enhanced photocatalytic performance

The development of efficient visible-light-driven photocatalysts is a great challenge due to their high charge recombination rate. Herein, BiVO4 nanoparticles with controllable oxygen vacancy levels were synthesized via a hydrothermal approach, followed by post-annealing treatment in an oxygen-deficient environment. The oxygen vacancy level within BiVO4 nanoparticles could be modulated by varying the annealing temperature between 300 and 400 degrees C in an Ar gas environment. Different oxygen vacancy levels could effectively change the bandgap of BiVO4, resulting in changes in photocatalytic efficiency. The BiVO4 nanoparticles with the optimal oxygen vacancy level showed a photocatalytic efficiency of 98%, which was 38% increased over pure BiVO4. A series of characterizations, including impedance spectra, transient photocurrent response, and electron spin resonance spectra, revealed that the increased photocatalytic efficiency was mainly ascribed to the efficient suppression of electron/hole recombination.

Automated summary

Efficient visible-light-driven photocatalysts face challenges due to high charge recombination rates. The development of BiVO4 nanoparticles with controllable oxygen vacancy levels has shown a significant increase in photocatalytic efficiency, with the optimal oxygen vacancy level leading to a 38% improvement over pure BiVO4. Characterizations revealed that this increase was mainly due to the suppression of electron/hole recombination.