Harnessing the visible light-assisted photocatalytic annihilation of methyl orange dye through nanostructured NiO/g-C3N4 composites: optimization of photocatalytic parameters
摘要
The exacerbated emission of synthetic dyes into aquatic environments from different industries results in immense hazards to the environment attributable to their noxious and non-biodegradable characteristics. Photocatalytic degradation has become recognized as an environmentally sustainable and effective strategy in addressing these contaminants. This work reports the development of an intriguing (NiO/g-C3N4) composite photocatalyst through an effective hydrothermal method for enhancing visible light-induced mitigation of methyl orange (MO) dye. The photocatalyst’s structural, morphological, surface, and optical characteristics were evaluated by XRD, XPS, SEM, BET, and UV-DRS techniques. The amalgamation of wide-bandgap NiO and narrow-bandgap g-C3N4 develops a heterojunction leading to improved charge separation, increases its ability to absorb light into the visible spectrum, and enlarges surface area. The NiO/g-C3N4-20 heterojunction revealed a substantially improved degradation performance of 97.34% in 60 min with a rate constant of 0.0642 min−1 compared to NiO/g-C3N4-30 (94.59% and 0.0523 min−1), NiO/g-C3N4-10 (88.77% and 0.0377 min−1), NiO (67.91% and 0.0192 min−1), and g-C3N4 (20.37% and 0.0037 min−1). Radical quenching studies substantiated the paramount involvement of superoxide radicals (O2•−) and hydroxyl radicals (•OH) in the degradation pathway. The heterojunction manifested outstanding reusability all through multiple uses with little change in functionality. The current study emphasizes the exciting potential of NiO/g-C3N4-20 heterojunction as effective, robust, and affordable photocatalysts for wastewater management purposes. Future endeavors will be centered on developing the interface architecture and evaluating actual wastewater treatment facilities for real-world implementation.
Graphical abstract