Visible-Light-Induced photocatalytic oxidation of gaseous ammonia on Mo, c-codoped TiO2: Synthesis, performance and mechanism

Ammonia gas (NH 3 ) is a notorious malodorous pollutant with detrimental effects on environment and human health. Removing NH 3 through photocatalytic oxidation remains a challenging task due to unclear reaction mechanisms. In this study, DFT simulation results revealed that C doped TiO 2 could extend the photo-response range to the visible region, but the introduction of deep impurity levels was found to accelerate photogenerated carrier recombination. Fortunately, the rational doping of Mo was found to mitigate this negative effect. Accordingly, Mo, C co-doped TiO 2 was synthesized via a facile low-temperature calcination process, resulting in unique band structure that enhanced the photocatalytic oxidation of NH 3 . Notably, in-situ DRIFTS and DFT results demonstrated that the gradual reaction of NH 3 adsorbed on Mo atoms with oxygen species through the N 2 H 4 mechanism, promoting the formation of N 2 . These findings offer insights into the design of efficient photocatalysts for NH 3 removal under visible light, and present a promising technology for indoor air pollution control.