Synthesis and photocatalytic performance of a WSe2QD/N-GO nanocomposite under visible light irradiation

Abstract

As an excellent semiconductor, tungsten selenide (WSe2) has been widely used in photocatalysis experiments. Tungsten selenide quantum dots (WSe2QD) with a particle size of 7–8 nm were prepared by mechanical stripping for the first time. A tungsten selenide quantum dot/nitrogen-doped graphene oxide (WSe2QD/N-GO) composite photocatalyst was synthesized by a simple hydrothermal synthesis method using tungsten selenide quantum dots and nitrogen-doped graphene oxide with a certain proportion. The prepared composites were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy and elemental mapping. The catalytic properties of the composites were evaluated by the degradation of methylene blue (MB) under visible light. The results show that the photocatalytic performance of the composites is better than WSe2 and nitrogen-doped graphene oxide (N-GO). Meanwhile, the optimum composite ratio of the composite is 4.7%. When the compound dosage was only 0.01 g, the photocatalytic degradation rate of 1.0 × 10–4 mol/L MB reached 92.7%. WSe2QD/N-GO has the advantages of simple preparation, low dosage and high photodegradation rate, which provides a research basis for the study of photocatalysts in the direction of quantum dots.