Dimensional Engineering of 1D/2D Synergistic TiO Nanostructures for High-Efficiency Photocatalytic CO Reduction.

Alongside the gradual progress of industrialization and the continuous development of human society, the problems of environmental pollution and energy crisis have become increasingly prominent. Semiconductor photocatalysis is a promising solution to these challenges. The photocatalytic reduction of CO by TiO to produce carbon monoxide and methane is a process which has been identified as a means of developing clean energy. In this paper, two-dimensional TiO (2D-TiO) was synthesized via a one-step solvothermal method, and one-dimensional TiO (1D-TiO) was obtained through a hydrothermal process. Their photocatalytic CO reduction performances were systematically investigated. The results show that 2D-TiO exhibits superior catalytic activity compared to 1D-TiO, which can be attributed to its lamellar structure, larger specific surface area, and improved hydrophilicity, providing more active sites and faster reaction kinetics. To further reveal the reaction mechanism, density functional theory (DFT) calculations were carried out using VASP with the GGA-PBE functional, PAW potentials, and a plane-wave cutoff energy of 520 eV. A 3 × 3 × 1 Monkhorst-Pack grid was used for Brillouin zone integration, and all possible adsorption configurations of CO*, COOH*, and CO* intermediates on the 2D-TiO surface were evaluated. The results confirm that 2D-TiO stabilizes key intermediates more effectively, thereby lowering the energy barrier and facilitating CO reduction. These findings demonstrate that structural modulation of TiO significantly influences its photocatalytic performance and highlight the great potential of 2D-TiO for efficient CO conversion and clean energy applications.