Fabrication and enhanced CO₂ reduction performance of N-self-doped TiO₂ microsheet photocatalyst by bi-cocatalyst modification

Exploiting advanced photocatalyst to reduce carbon dioxide (CO₂) into solar fuels is important. In particular, the combined improvement in visible-light harvesting ability, charge separation and utilization efficiency is essential to enhance photocatalytic CO₂ reduction performance. Herein, N-self-doped anatase TiO₂ (NT) microsheets with proper coexposed {101} and {001} facets were first prepared via simple hydrothermal method using HF as capping agent and TiN as precursor. Then, the exposed {101} and {001} facets of the as-prepared NT microsheets were further modified by simultaneous photodeposition of Ag and MnOₓ nanoparticles (NPs), respectively. The resulting Ag and MnOₓ co-modified NT microsheets showed good visible-light absorption ability, excellent charge separation, and utilization efficiency and consequently exhibited the highest visible-light photocatalytic CO₂ reduction rate to methanol (0.53 μmol h⁻¹ g⁻¹). The enhanced photocatalytic activity is attributed to the synergistic modification of the visible-light harvesting ability of nitrogen doping, as well as charge separation and utilization efficiency by the combination of proper facet design and cocatalyst deposition together with Surface Plasmon Resonance (SPR) effect induced by Ag. TiO₂ modification techniques may shed some light on the future development of advanced visible-light-driven photocatalysts. Copyright © 2016 Elsevier Ltd.