Single-crystalline 2D BiOCl nanorods decorated with 2D MoS2 nanosheets for visible light-driven photocatalytic detoxification of organic and inorganic pollutants

Abstract

Visible light-driven photocatalytic degradation is one of the promising ways to deal with the major problem of water pollution. This study involves one-step, fast, in-situ preparation of BiOCl/MoS2 (2D/2D) heterostructure via microwave irradiations. The photocatalytic performance of BiOCl/MoS2 composite with different weight ratios (1:1, 3:1, and 1:3) have been evaluated for degradation of organic (methylene blue (MB) dye, fipronil pesticide) and inorganic pollutants (Cr(VI)) along with real industrial wastewater under visible light irradiation. XRD, XPS, FESEM, HRTEM, and SAED analysis indicate the formation of single-crystalline nanorods with a high aspect ratio of 1:10. The composites possess high surface area (~40 m2/g) with lower charge recombination and high visible light absorption tendency due to lower band gap (2.30 eV) energy. The high synergistic interaction (~2.29) between BiOCl and MoS2 results in enhancement of degradation activity which shows 94%, 89%, and 90% removal of MB, fipronil, and Cr(VI) metal, respectively by BiOCl/MoS2 (1:3) catalyst. The optimum conditions to get maximum degradation efficiency were determined by varying different reaction parameters like pH, catalyst dose, and illumination area. Radical trapping experiments indicate that holes and hydroxyl radicals had a dominant role in the degradation process. The catalyst is highly stable and reusable as confirmed by the reusability studies. The photocatalytic treatment of industrial wastewater without any physico-chemical pretreatment showed 75% COD and 63% TOC removal under visible light, which indicates high practical efficiency of the catalyst. The current study validates that the BiOCl/MoS2 composites with superior characteristic properties can be efficiently used for wastewater treatment under natural light.