Single titanium-oxide species implanted in 2D g-C₃N₄ matrix as a highly efficient visible-light CO₂ reduction photocatalyst

A visible-light-response, efficient and robust photo-catalyst for CO₂ reduction is highly desirable. Herein, we demonstrate that single titanium-oxide species implanted in two-dimensional (2D) graphitic carbon nitride (g-C₃N₄) matrix (2D TiO-CN) can efficiently photo-catalyze the reduction of CO₂ to CO under the irradiation of visible light. The synergistic interaction between single titanium oxide species and g-C₃N₄ in 2D TiO-CN not only enhances the separation of photo-excited charges, but also results in visible light response of single titanium-oxide species, realizing high activity of CO₂ photo-reduction with extremely high CO generation rate of 283.9 μmol·h⁻¹·g⁻¹, 5.7, 6.8 and 292.2 times larger than those of TiO₂/CN hybrid material, CN and commercial TiO₂, respectively. Time-resolved fluorescence and electron spin resonance spectroscopy revealed the catalytic mechanism of the fabricated 2D TiO-CN photocatalysts for CO₂ reduction.