Template-Assisted Galvanic Replacement Synthesized Pt/Co3O4/TiO2 for Efficient Visible-Light Degradation of Tetracycline and Methylene Blue

To overcome the poor visible light response and high recombination rate of photogenerated carriers in bare TiO 2 , a Pt/Co 3 O 4 /TiO 2 photocatalyst was fabricated via a template-assisted spontaneous galvanic replacement route. The as-prepared material contains anatase–rutile mixed-phase TiO 2 , Co 3 O 4 , and metallic Pt and retains a dodecahedral morphology with a high specific surface area of 122.64 m 2 /g. Under visible light irradiation for 120 min, its degradation rates for tetracycline and methylene blue reached 85% and 93%, respectively, which are significantly better than those of pure TiO 2 and Pt/Co 3 O 4 . The composite also exhibited excellent stability and recyclability. Its superior performance is ascribed to the synergistic effects of the mixed-phase TiO 2 , the p–n heterojunction between TiO 2 and Co 3 O 4 , the Schottky barrier at the Pt/TiO 2 interface, the localized surface plasmon resonance of Pt, and the high adsorption capacity of the porous material. This work offers a new strategy for treating dye- and antibiotic-containing wastewater.