The observed increase in particle size with higher dopant concentrations has significant implications for the photocatalytic performance of the synthesized materials. In photocatalysis, particle size plays a critical role in determining the surface area available for reactions. Smaller particles generally offer a higher surface-to-volume ratio, providing more active sites for the adsorption of pollutants and the generation of reactive oxygen species (ROS). Consequently, the larger particle size observed for the 1B-1Ce-0.06Ag-TiO₂ catalyst may lead to a reduction in the overall surface area, potentially impacting its photocatalytic efficiency despite its slightly modified band gap.