## 1 Introduction
The presence of dye in industrial wastewater, even at low concentrations, can visibly hinder sunlight from penetrating the water, causing a reduction in photosynthesis and imposing strict regulations on the organic content of polluted water. Additionally, long-term exposure to MB can be detrimental to human health, leading to gastrointestinal issues, central nervous system dysfunction, and kidney damage [22]. It is worth noting that MB exhibits high resistance to degradation from environmental factors such as light, temperature, and biological activity [23]. Hence, it is of utmost importance to identify the most efficient method for eliminating MB from water to safeguard both the environment and human well-being. Wastewater treatment techniques for dye removal are typically grouped into three categories: physical, chemical, and biological. Physical methods such as adsorption, ion exchange, oxidation, and irradiation are commonly used but can be labor-intensive, consume a lot of power, and require multistage processing [24]. However, the photocatalytic degradation process is becoming increasingly popular as an effective dye removal method [25]. It is an effective and environmentally friendly method for the degradation of dyes in wastewater. Its selectivity, efficiency, versatility, and cost-effectiveness make it a promising option for the treatment of colored effluents from different industries. This process oxidizes the large molecules of dyes into smaller by-products such as water, carbon dioxide, and minerals. It is a contemporary technique extensively utilized for the breakdown or whitening of dyes [26]. This method entails the transfer of electrons from the valence band to the conduction band on a semiconductor surface when illuminated with light of a suitable wavelength. The excitons produced then interact with water or oxygen, generating hydroxide radicals and superoxide anions, which have potent oxidizing properties for breaking down various molecules, including dyes [27]. These decontamination procedures utilizing reactive oxygen species and other reactive species are collectively known as Advanced Oxidation Processes (AOPs) [28]. Conventional methods have been effective in removing dyes from water, but they often have limitations in terms of efficiency, selectivity, and cost [29]. Among the existing chemical, physical, and biological methods for the degradation of harmful dyes, nanotechnology reductive degradation has demonstrated significant qualities [30]. Nanotechnology-based approaches for the removal of dyes from water include the use of nanomaterials such as nanoparticles, nanotubes, and nanofibers. These materials offer a high surface area-to-volume ratio, which enhances their reactivity and makes them more effective in removing dyes from water. They can also be designed to be selective towards specific dyes, which increases their efficiency and specificity [31]. Recent studies have found that transition metal oxides have drawn research interest because of their compact size and large reactive surface area, which paved their way in various fields, including catalytic, chemical, optical, magnetic, and electrical [32; 33; 34]. In metal oxide NPs, the cobalt oxide (Co\({}_{3}\)O\({}_{4}\)) NPs and their composites are well known to be suitable catalysts for water oxidation and as light absorbers with wide band gaps because of their dual activity [35; 36]. The non-stoichiometric polymorph Co\({}_{3}\)O\({}_{4}\) has drawn significant interest among the other numerous cobalt oxidation states that are possible, including cobaltous oxide (CoO), cobaltic oxide (Co\({}_{2}\)O\({}_{3}\)), and cobaltosic oxide (Co\({}_{3}\)O\({}_{4}\)), because of its structural, redox and highest stability characteristics [37].