Phosphate-bridged CNT/TiO2 composites with engineered charge-transfer interfaces for high-efficiency photocatalytic remediation

Harnessing solar energy for environmental remediation is a pivotal strategy; however, the photocatalytic efficiency of titanium dioxide (TiO₂) remains constrained by rapid charge-carrier recombination. To address this limitation, we report the rational design of a composite photocatalyst featuring an engineered charge-transfer interface between commercial TiO₂ (P25) and phosphorylated carbon nanotubes (P-CNT). By anchoring P-CNT onto the P25 surface, we established Ti-O-P chemical bridges that facilitate intimate interfacial contact and accelerated charge transport. In this architecture, the P-CNT serve as an efficient electron sink, rapidly extracting photogenerated electrons from P25 to suppress recombination and enhance the generation of reactive oxygen species. Consequently, the optimized composite (1 wt % P-CNT loading) exhibited significantly enhanced performance, achieving complete decolorization of Rhodamine B within 2 h under simulated solar irradiation. This work provides a robust strategy for the interfacial engineering of high-efficiency photocatalysts for environmental applications.