Superior photocatalytic degradation of Reactive Orange 16 by Ag–AgCl/BiOCl nanocomposites under visible light

Abstract

Due to unregulated dumping, the concentration of reactive dyes in wastewater has consistently increased. To mitigate their harmful nature, successful eradication becomes crucial. In this regard, Ag–AgCl–BiOCl nanocomposites were constructed utilizing a simple co-precipitation approach to evaluate the photocatalytic degradation activity towards Reactive Orange 16 in the presence of visible light. The synthesized catalyst was characterized using different methods, including field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS), etc. Furthermore, XPS spectra show the co-existence of Ag(0) and Ag(+1) in the nanocomposite. The loading of Ag–AgCl results in lowering of electron–hole pair recombination and charge transfer resistance. As a result, AB10 outperformed all other nanocomposites in terms of photocatalytic activity, achieving 92% in 90 minutes. The control experiments suggest that holes act as the reactive species in the photocatalytic reactions, whereas electrons, hydroxyl radicals, and superoxide anions do not participate in the degradation process. Remarkably, Bi(III) acts as an electron scavenger to afford Bi(0). Ag(0), as well as the in situ generated Bi(0), can play an imperative role in improving the photocatalytic degradation efficiency owing to the localized surface plasmon resonance phenomenon. Furthermore, high-resolution mass spectroscopy (HRMS) confirms the presence of smaller fragments, resulting in a more in-depth understanding of the photocatalytic degradation process. The synthesized catalyst is exceptionally stable and recyclable. As a result, the photocatalyst has the potential to eliminate the reactive dye from wastewater.