A significant amount of resources is contained within the sludge, and the achievement of sludge reduction and resource utilization is considered a global environmental challenge. High-value TiO₂ nanoparticles are recovered from the titanium-coagulated algae-rich sludge through the application of a one-step calcination method, and a Pt-loaded titanium dioxide photocatalytic material (Pt@TiO₂) is obtained through photodeposition, effectively enabling the resource utilization of the sludge.Pt@TiO₂ with nanospherical (mesoporous) structure, and lowband gaps (compared to P-25), were obtained. Based on the results of electron spin resonance spectroscopy (ESR), hydroxyl radicals and superoxide radicals are produced by the recovered Pt@TiO₂ under illumination, both of which can be utilized as active oxidative species involved in oxidation reactions. The impact of Pt@TiO₂ dosage, solution pH, 4-chlorophenol (4-CP) concentration, and humic acid concentration on the photocatalytic performance of Pt@TiO₂ was investigated. The results indicate that under ultraviolet light irradiation, 0.3% Pt@TiO₂ can completely degrade 20 mg/L of 4-CP within 60 minutes. Recycled Pt@TiO₂ was subjected to cyclic tests, and even after five cycles, 92.5% of 4-CP could still be degraded. This study offers a method for the resource recovery and reuse of algae-rich sludge, presenting a new avenue for achieving environmentally sustainable development.