Ce‐Doped SnO ₂ Nanoparticles for Efficient Photocatalytic Degradation of Organic Dyes and Antibiotics Under Sunlight Exposure

Ce‐doped SnO 2 nanoparticles (CSNPs) were synthesized via a hydrothermal precipitation method followed by annealing at 600°C for 2 h under ambient conditions, and evaluated as sunlight‐driven photocatalysts for the degradation of organic dyes and antibiotics. X‐ray diffraction analysis confirmed the formation of a tetragonal rutile SnO 2 crystal structure for all Ce concentrations, with no secondary phases detected. The CSNPs exhibited enhanced light absorption and favorable surface properties, thereby improving photocatalytic performance. Among the CSNPs, Ce = 5 at.% (CS5) showed the highest activity, achieving degradation efficiencies of ∼95.36% for crystal violet (CV), ∼93.39% for methylene blue (MB), ∼86.66% for methyl orange (MO), and ∼79.00% for ciprofloxacin (CPF) under natural sunlight irradiation. The enhanced activity of CSNPs is attributed to bandgap narrowing (3.50 → 3.35 eV), efficient charge separation, and the generation of reactive oxygen species (•O 2 − and •OH). Radical‐trapping experiments demonstrate the potential of CSNPs as a cost‐effective photocatalyst for water purification.