Plasma Cu-decorated TiO2−x/CoP particle-level hierarchical heterojunctions with enhanced photocatalytic-photothermal performance

Plasma Cu-decorated TiO2−x/CoP particle-level hierarchical heterojunction photocatalysts with surface engineering were fabricated through solvothermal and solid phase reduction strategies. The CoP nanoparticles not only serve as a cost-effective cocatalyst but also provide abundant surface active sites, which facilitate rapid transfer of photogenerated carriers. The Ti3+ and oxygen vacancy defects extend photoresponse from UV to visible light region, and enhance the separation efficiency of photogenerated carriers efficiently. Because of surface plasma resonance (SPR) of Cu, Cu/TiO2−x/CoP with average particle size of 100–200 nm has significant photothermal effect, in which the temperature of Cu/TiO2−x/CoP is increased by 76 °C with irradiation for 30 s, ~ 8 times higher than that of the original TiO2. Cu/TiO2−x/CoP exhibits a high photocatalytic degradation rates for highly toxic 2,4-dichlorophenol (99.2%) and 2,4,6-trichlorophenol (98.5%), which higher 7.6 and 8.9 times than the initial TiO2, respectively. Thanks to the particle-level hierarchical heterojunction, the efficient surface engineering and SPR effect favoring the spatial charge separation, Cu/TiO2−x/CoP shows excellent photocatalytic-photothermal Performance. This particle-level hierarchical heterojunction architectural design provides a new insight for synthesizing particulate photocatalysts with high-efficiency.