Microwave synthesized ternary BiOCl/BiOBr/Bi2O3 nanocomposite for enhanced degradation of organic contaminants under visible light exposure

Abstract

Background

This research addresses the urgent need for efficient water treatment methods to treat water pollution resulting from industrial activities and population growth. It focuses on developing semiconductor-based photo-catalysts with enhanced photocatalytic activity under visible light, aiming to contribute to pollution control and sustainable energy solutions.

Methods

A novel layer-structured ternary BiOCl/BiOBr/Bi₂O₃ nanocomposite was successfully synthesized via a rapid, one-step microwave-assisted method. The unique layered structure of this heterojunction facilitated efficient migration and separation of photoinduced electron-hole pairs, essential for effective photocatalysis.

Significant Findings

The synthesized nanocomposite exhibited excellent photocatalytic performance, achieving complete degradation of 30 mg L⁻¹ RhB, 98.0% efficiency for 10 mg L⁻¹ TCH, and 83.0% efficiency for 10 mg L⁻¹ MO. Furthermore, the photo-catalyst displayed remarkable photostability, retaining 99.7% efficiency even after seven cycles of RhB degradation. The study also revealed favorable conditions for RhB degradation, emphasizing the impact of high temperature and low pH media while demonstrating the catalyst's resilience to the presence of ions (NO₃⁻, Cl⁻, SO₄²⁻, and NH₄⁺). The study indicates that singlet oxygen (¹O₂) was predominant among the oxidizing species in photodegradation. This work introduces a highly efficient and stable ternary BiOCl/BiOBr/Bi₂O₃ nanocomposite as a promising solution for addressing water pollution issues and harnessing visible light for photocatalytic applications.