Plasma Cu-decorated TiO/CoP particle-level hierarchical heterojunctions with enhanced photocatalytic-photothermal performance.

Plasma Cu-decorated TiO/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 Ti 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/TiO/CoP with average particle size of 100-200 nm has significant photothermal effect, in which the temperature of Cu/TiO/CoP is increased by 76 °C with irradiation for 30 s, ~ 8 times higher than that of the original TiO. Cu/TiO/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 TiO, respectively. Thanks to the particle-level hierarchical heterojunction, the efficient surface engineering and SPR effect favoring the spatial charge separation, Cu/TiO/CoP shows excellent photocatalytic-photothermal Performance. This particle-level hierarchical heterojunction architectural design provides a new insight for synthesizing particulate photocatalysts with high-efficiency.