Modulating Ti t_2g Orbital Bonding in Dual-Channeled TiO₂/rGO Hybrid Architecture for Stable Photocatalytic Methanol to Hydrogen

Carbon materials are commonly integrated with TiO₂ to achieve high carrier mobility and excellent photocatalytic performance, and the chemical bond between TiO₂ − C is considered as a significant strategy to enhance efficiency. Nevertheless, few analyses have elucidated the formation mechanism of Ti^{3 +} − C bonds and the underlying reasons for the performance enhancement. To address these issues, this study conducts an in-depth investigation into the electronic structure of TiO₂ − C and demonstrates that the charge in the nonbonding molecular orbital t_2g of Ti^{3 +} is transferred to the unoccupied 2p energy level of C through the formation of 1π and 2π bonds, i.e., (Ti 3d_xz - C 2p_y) and (Ti 3d_xy - C 2p_x). The hybridization of t_2g-2p orbitals endows the Ti^{3 +} − C bond with higher carrier mobility and a stronger binding force, thereby contributing to stable photocatalytic H₂ production. Inspired by this scenario, the NSTiO₂/rGO hybrid architecture, featuring the {101}/{001} surface heterojunction and the Ti^{3 +} − C interfacial chemical bond, has been constructed. As a result, the hybrid catalyst exhibited excellent photocatalytic cycling stability of (Formula presented.) and an H₂ evolution rate of 33.4 mmolh⁻¹g⁻¹. This work proposes a strategy for designing efficient photocatalyst by regulating orbitals to achieve high-performance photocatalytic methanol splitting.