Indium-doped tungsten oxide architectures anchored on 2D rGO Matrix with enhanced visible-light-response and efficient charge separation for photocatalytic degradation of organic pollutants

Abstract

Visible-light-responsive photocatalysis has been recognized as a sustainable strategy to address environmental pollution, but semiconductor-based photocatalysts often suffer from many shortcomings, including low visible light absorption and rapid recombination of photo-generated charge carriers. In this regard, rationally designed composite materials have gained substantial prominence, as achieving an ideal photocatalyst's characteristics in a single component material is frequently difficult. In the present study, we have synthesized pure (WO3) and indium-doped tungsten oxide (In-WO3) by the facile solvothermal route. The doped material was anchored on a 2D rGO matrix to fabricate the In-WO3/rGO composite. The structural, morphological, electrical, and optical properties of the as-synthesized materials were investigated as a function of doping and composite fabrication by various physical and electrochemical techniques. The comparative photocatalytic performance was evaluated by degrading Congo Red (CR) dye and paracetamol (PCM) drug. The composite material shows degradation efficiencies of ∼96 % (K=0.0174 min−1) and ∼91 % (K=0.0144 min−1) for CR dye and PCM drug, respectively. The boosted catalytic performance corresponds to the declined band gap (2.53 eV) and increased conductivity (0.1270 Sm−1), which enhances its visible light absorption and a surge in the charge carrier's population. The kinetics, relative contribution of different active species generated, and the potential mechanism of photodegradation reaction are discussed in detail. The significant increase in photocatalytic performance of the fabricated In-WO3/rGO composite discloses its promising catalytic potential for the degradation of recalcitrant organic pollutants.