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

Abstract

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 (0.53μmolh−1g−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.