Novel solar-light-driven Z-scheme BiOCl@WS2 nanocomposite photocatalysts for the photocatalytic removal of organic pollutants

Abstract

Considering the strong sunlight-absorption property of WS₂ and the good photocatalytic activity of BiOCl, a solar-light-active Z-scheme BiOCl@WS₂ nanocomposite photocatalyst was synthesized by a precipitation approach. The developed photocatalyst was systematically characterized using available precision instruments. The photocatalytic property of the synthesized photocatalyst toward methyl orange (MO), rhodamine B (RhB), and crystal violet (CV) as anionic and cationic model organic dyes was investigated. In addition, the influence of operational factors, such as the catalyst dose, dye concentration, and pH, on the photocatalytic performance of the proposed photocatalyst was examined. The degree of mineralization of the fabricated Z-scheme BiOCl@WS₂ nanocomposite photocatalyst during photodegradation of CV was also evaluated via total organic content (TOC) measurements. The findings showed that the developed Z-scheme BiOCl@WS₂ nanocomposite exhibited excellent photocatalytic properties toward the organic pollutants MO, RhB, and CV. Moreover, the nanocomposite exhibited a better photocatalytic activity when compared with that of the solar-light-active photocatalysts reported in the open literature. It also displayed the potential to photocatalytically degrade 81% of MO, 100% of RhB, and 95% of CV within 120 min. Besides, 88% of CV could be mineralized by the fabricated photocatalyst in two hours. The outstanding photocatalytic performance of the Z-scheme BiOCl@WS₂ nanocomposite could be attributed to the narrow band gap, large surface area, extended optical activity, and suppressed charge recombination rate. Thus, this work opens the door for developing effective, efficient, and stable solar-light-active photocatalysts for the photodegradation of organic dyes in wastewater.