Enhanced photocatalytic activity of two dimensional ternary nanocomposites of ZnO-Bi2WO6-Ti3C2 MXene under natural sunlight irradiation

Abstract

The design and development of advanced photocatalysts for water purification have attracted much attention from researchers in recent years. In this context, the two-dimensional (2D) semiconducting materials have shown excellent photocatalytic properties due to their merits of high surface area, confined longitudinal dimensions and excellent capability of efficient separation and transfer of photogenerated charge carriers. Herein, we report a novel 2D-2D-2D ternary photocatalyst ZnO-Bi₂WO₆-Ti₃C₂ by using a two-step electrostatic assembly route. The formation of the individual materials and nanocomposites was confirmed by x-ray diffraction and 2D morphology was ascertained by electron microscopy studies. The as-prepared photocatalysts were utilized for the degradation of a colorless pharmaceutical pollutant, ciprofloxacin (CFX) under natural sunlight irradiation. It was found that the optimized ternary photocatalyst showed a maximum degradation (∼77%) of CFX in 160 min. The mechanistic investigation showed that upon nanocomposite formation, the electrons flow from ZnO and Bi₂WO₆ to Ti₃C₂, implying that MXene plays an important role in the separation of photogenerated charges and thereby enhancing the photocatalytic activity. This work paves the way for the design and development of efficient photocatalysts for environmental remediation.

Keywords: Ciprofloxacin; MXene; Photocatalysis; Pollutants degradation; Semiconductors.