Gd-N Co-doped TiO2/macroporous resin photocatalyst for enhanced visible-light degradation of organic pollutants

To address the critical limitations of TiO 2 photocatalysts, including insufficient visible-light response and rapid carrier recombination, this study developed a Gd-N co-doped hierarchical porous TiO 2 -macroporous resin (Gd/N/TiO 2 -MAR) composite via a sol-gel hydrothermal method. Multi-scale characterizations (XRD, XPS, BET) revealed that Gd 3 ⁺ doping modulates the band structure and surface properties through 4f-2p orbital hybridization, extending the light response range while suppressing carrier recombination via electron trapping. The hierarchical porous architecture and interfacial synergy significantly enhanced the adsorption-photocatalytic degradation efficiency. Under visible light, the composite exhibited a 1.6-fold higher degradation rate constant for Rhodamine B compared to single N-doped systems, alongside stable performance across a broad pH range (2−12) and under coexisting ion interference. Radical trapping and adsorption-photodegradation kinetic analyses elucidated the cooperative mechanism of interfacial charge transfer and reactive species generation. This work provides new structural design principles for developing efficient multifunctional materials for environmental remediation.