ABSTRACT CuO nanoparticles were synthesized using Sargassum cristaefolium extract as a green reducing and capping agent for wastewater treatment applications. The CuO nanoparticles were characterized using UV–vis, FTIR, BET, XRD, TG/DTA, SEM, TPD‐NH 3 , TPD‐CO 2 , HRTEM, and EDX techniques. UV–vis analysis showed an SPR peak at 275 nm with a band gap of 3.35 eV. BET results confirmed a mesoporous structure. TG/DTA analysis showed weight loss at lower temperatures with negligible changes at higher temperatures, indicating high thermal stability. TPD studies showed dominant surface acidity and a total active site density of 5.325 mmol g − 1 , beneficial for dye degradation. HR‐TEM and SEM images confirmed spherical morphology, while EDX verified elemental purity. Photo‐catalytic studies demonstrated 73.75% ± 0.1% degradation of methylene blue within 50 min under sunlight, following pseudo first order kinetics. The photo‐catalytic mechanism was confirmed by quencher experiments. Different factors affecting the photo‐catalytic activity of CuO, such as temperature (35°C, 45°C, 55°C) and catalyst concentration (10, 20, 30 mg), were investigated. Thermodynamic parameters, such as activation energy, Gibbs free energy, enthalpy, and entropy, were calculated. The CuO photo‐catalyst retained good stability over three cycles and exhibited promising electrochemical behavior, highlighting its potential in environmental remediation and energy storage applications.
Deepika et al. (Tue,) studied this question.