Graphene-Oxide Hierarchical TiO₂@Ag Nanocomposite: An Efficient Solar Driven Photocatalyst for Degradation of Phenol in Aqueous System

In this study, we report the synthesis of GO-TiO₂@Ag nanocomposite via a simple and modified polyol method and its application for the enhanced degradation of phenol in real water samples under solar irradiation. The nanocomposites were characterized by FE–SEM, FT-IR, EDX, BET, XRD, ZP, and DLS, revealing key properties such as high BET surface area (340.977 m²/g) and the negative zeta potential (−23.7 mV), which contributed to colloidal stability and prevented aggregation, enhancing the photocatalytic performance. The particle size of 141.7 nm maximized the active surface area, leading to enhanced photocatalytic activity. The photocatalytic performance was evaluated in an aqueous medium without the use of chemical additives. The influence of catalytic dose (40 mg/L), phenol concentration (50 mg/L), and reaction time (5 h) on degradation efficiency was optimized under solar radiation. The degradation process followed pseudo-second-order kinetics and the Morris–Weber model. The nanocomposite exhibited excellent stability and reusability with an initial turnover frequency (TOF) of 92.02 (mol Catalyst)⁻¹•(min)⁻¹. The maximum degradation efficiency of 92% was achieved under optimized conditions (phenol concentration of 50 mg/L and catalytic dose of 40 mg/L) within 5 h of solar-assisted degradation. The high BET surface area of 340.977 m²/g and abundant active sites contributed significantly to the enhanced catalytic performance. These results underscore the potential of GO-TiO₂@Ag nanocomposite as an efficient photocatalyst for phenol degradation in aqueous environments.