Designing dual-defective photocatalyst of Z-scheme H-BiVO4/D-NG composite with hollow structures for efficient visible-light photocatalysis of organic pollutants

Photocatalytic degradation using sunlight is attractive due to its high efficiency, low cost and environmental friendliness. This study successfully synthesized a dual-defective H-BiVO4/D-NG hollow structure photocatalyst was discretely decorating hollow BiVO4 (H-BiVO4) on dual defect graphene (D-NG) by hydrothermal method. The characterization of the structure, morphology, optical and electrochemical properties was carried out. The effects of different catalysts, annealing temperature, catalyst dosage and different reaction temperature on the photocatalytic degradation of BPA were investigated to explore the property of photocatalytic reactor. Especially, the H-BiVO4/D-NG composite showed the highest photocatalytic activity, which could degrade 98% of BPA in 30 min and remove 81% of total organic carbon (TOC) in 120 min. In addition, the cycling experiments and XRD patterns before and after the photocatalytic reaction showed that the catalyst exhibited outstanding stability, which is conducive to practical applications in the field of photocatalysis. Furthermore, electron spin resonance (ESR) and active radical trapping experiment indicated that the prepared nanocomposites followed a direct Z-scheme mechanism. The results showed that a combined strategy of introducing defect engineering and morphology control in photocatalyst design can effectively improve photocatalytic activity. It's expected to provide new ideas for the preparation of high-performance photocatalysts.