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

Abstract To overcome the poor visible light response and high recombination rate of photogenerated carriers in bare TiO2, a Pt/Co3O4/TiO2 photocatalyst was fabricated via a template-assisted spontaneous galvanic replacement route. The as-prepared material contains anatase–rutile mixed-phase TiO2, Co3O4, and metallic Pt and retains a dodecahedral morphology with a high specific surface area of 122.64 m2/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 TiO2 and Pt/Co3O4. The composite also exhibited excellent stability and recyclability. Its superior performance is ascribed to the synergistic effects of the mixed-phase TiO2, the p–n heterojunction between TiO2 and Co3O4, the Schottky barrier at the Pt/TiO2 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.