Surfactant-free hydrothermal fabrication of monoclinic BiVO4 photocatalyst with oxygen vacancies by copper doping

Abstract

Poor electron transport leads to the high recombination of photogenerated charge carriers for photocatalysts, which limits the photocatalytic performance. In order to improve charge transport properties, Cu doped BiVO₄(Cu–BiVO₄) was prepared by a facile hydrothermal method. The doped material provided a maximal photocurrent of 10 μA cm⁻² at +0.4 V vs. SCE, which was 5 times higher than the undoped one. The result implied much improvement for the separation of the carriers for Cu–BiVO₄, which attributed to the suitable amount of oxygen vacancies as positive charge centers caused by doping. Oxygen vacancies trapped photogenerated electrons and thus inhibited the electrons–holes recombination. The photocatalytic degradation of rhodamine B (RhB) was used to evaluate the photoactivity of the materials. The results showed that the photocatalytic properties of the doped materials were evidently higher than the undoped BiVO₄. The photocatalytic reaction mechanism is also discussed in this article, and the superoxide radical was confirmed to be the main active species for the photocatalytic degradation process.