Exploring the impact of <scp>SDS</scp> ‐modified <scp>ZnO</scp> – <scp> CeO ₂ </scp> nanocomposites on photocatalytic degradation and antibacterial activity

Abstract The objective of this study is to develop an efficient photocatalyst for the elimination of detrimental organic pollutants from the contaminated water system. Sustainable textile effluent treatment necessitates approaches that proficiently eliminate pollutants, diminish costs, prevent secondary pollution, and permit water recycling. In this study, ZnO–CeO 2 and SDS‐modified ZnO–CeO 2 nanoparticles with varying morphologies and crystallite sizes were synthesized via a facile co‐precipitation method. The structural, morphological, and elemental characteristics of the prepared photocatalysts were systematically analyzed using XRD, FTIR, UV–Vis, EDX, and FE‐SEM. The average crystallite size of ZnO–CeO 2 nanocomposites (18.69 nm) compared to that of SDS/ZnO–CeO 2 nanocomposites (21.82 nm) suggests that the presence of the SDS surfactant negatively impacts the structural properties of the ZnO–CeO 2 photocatalyst. Consequently, the SDS‐modified binary oxides demonstrated lower photocatalytic degradation efficiency compared to the unmodified ZnO–CeO 2 nanocomposites. The reduced activity is owing to congested active sites, excessive SDS, and organic remains. EDX confirmed residual carbon from SDS on the surface, which caused light absorption and charge separation. The unmodified binary oxide achieved 97.16%, 72.04%, and 27.18% degradation of CIP, MB, and MO, while the SDS‐modified oxide reached 88.47%, 61.46%, and 17.61% within 210 min under UV light. The degradation kinetics followed a pseudo‐first‐order model, with hydroxyl radicals identified as the predominant reactive species governing the photodegradation process. Moreover, ZnO–CeO 2 nanocomposites demonstrated superior antibacterial activity against both Gram‐positive and Gram‐negative bacteria compared to the SDS‐treated nanocomposites. The study demonstrates ZnO–CeO 2 's combined photocatalytic and antibacterial performance, supporting its usage as a multifunctional material for effluent treatment.