Magnetic recyclable self-floating solar light-driven WO2.72/Fe3O4 nanocomposites immobilized by Janus membrane for photocatalysis of inorganic and organic pollutants

Abstract

For environmental scientists, developing an efficient, stable, and recyclable solar light photocatalyst is a challenging issue. Even though powder photocatalysts have excellent photocatalytic activity, their recyclability and reusability is a noteworthy problem. Therefore, it is very crucial to develop a new photocatalysis system that possesses efficient photocatalytic activity, excellent stability, and ease of recyclability, and is free of secondary pollution. Herein, a solar light active WO2.72/Fe3O4 nanocomposite photocatalyst was immobilized in hydrophobic porous recycled triacetate cellulose (rTAC) to solve the reusability problem and was electrospun on hydrophilic nonwoven polyvinyl alcohol (PVA) to fabricate a self-floatable recyclable Janus membrane. TAC possesses very important properties such as high moisture permeability and high light transmittance, which helps all the light irradiated to be utilized by the photocatalyst and hydrophobicity, which increases the ease of floating. The recyclable Janus membrane was purposefully designed so that the contaminated water can be attracted by PVA due to its hydrophilicity and pass to porous rTAC, where the pollutant and the photocatalyst come into contact and photocatalysis takes place, while the hydrophobicity of the rTAC makes the Janus membrane float on the surface of polluted water. The photocatalytic property of the synthesized recyclable Janus membrane was studied for the photodegradation of rhodamine B (Rh B) and methylene blue (MB) as well as the photoreduction of the carcinogenic pollutant Cr(VI) under solar light irradiation. The recyclable Janus membrane presented an outstanding photocatalytic property for the photodegradation of Rh B and MB dyes and the photoreduction of Cr(VI). It also displayed excellent cyclic stability and ease of recyclability for both organic and inorganic pollutants after multiple experimental cycles. The Janus membrane also presented better photocatalytic activity than previously reported photocatalysts for MB photodegradation. Therefore, the developed interfacial photocatalysis system and the recyclable Janus membrane are promising candidates for environmental remediation under solar light irradiation. This study paves the way for the design of an environmentally friendly, effective, and stable photocatalyst for wastewater treatment.