Interface‐Engineered CuO / GO / TiO 2 Ternary Heterostructures for Adsorptive and Photocatalytic Removal of AY ‐25 Dye

ABSTRACT Acid Yellow‐25 (AY‐25) dye is a toxic pollutant that poses significant threats to both human health and the environment when discharged into aquatic systems. To resolve this problem, we have prepared graphene oxide (GO) nanoparticles (NPs), their binary (CuO/GO), and ternary (CuO/GO/TiO 2 ) nanocomposites (NCs). Pristine GO were synthesized by modified hummer's method, while copper oxide (CuO) and titanium dioxide (TiO 2 ) were integrated using simple co‐precipitation approach. The preparation of this system is supported by structural, surface, thermal, and morphological analysis. Under UV–Vis light irradiation, the CuO/GO/TiO 2 NCs degraded 93.79% of 80 ppm AY‐25 dye in 240 min at pH 5, catalyst loading of 0.03 g, and 303 K, surpassing GO and CuO/GO which exhibited degradation efficiencies of 71.47% and 84.96%, respectively, under identical conditions. The process of degradation was tested using pseudo‐first‐order and pseudo‐second‐order kinetics models, and thermodynamics approach: which gave information about the physicochemical nature of the photocatalytic process. Furthermore, the simultaneous incorporation of CuO and TiO 2 into GO enhanced light absorption, charge separation, and prolonged the lifetime of charge carriers, thereby increasing the photocatalytic activity. This study offers a straightforward method for designing and fabricating a novel ternary NCs photocatalyst with potential applications in wastewater treatment.