Controllable synthesis various morphologies of 3D hierarchical MnOx-TiO2 nanocatalysts for photothermocatalysis toluene and NO with free-ammonia.

Via various hydrothermal synthetic conditions, controllable synthesis various morphologies of MnOx-TiO2 catalysts for simultaneous removal toluene and NO with free-ammonia under the photothermocatalysis system based on UV light irradiation. The morphologies obtained included 3D hierarchical sheet structure (C sample), 3D hierarchical sheet stacked MnOx-TiO2 microspheres (P sample), and 3D hierarchical sticks stacked MnOx-TiO2 microspheres (N sample). Compared with other samples, N sample exhibited the excellent catalytic activity for the toluene and NO, with the conversion rates of toluene and NO achieved 72% and 91% at 240 °C, respectively. Using a variety of characterization and analysis methods, it was confirmed that the morphology of the catalysts would affect its catalytic performance by affecting the specific surface area, surface-adsorbed oxygen species, oxygen vacancies, the high-valence atomic species and reducibility. This was the reason why the N sample could show remarkable performance. Moreover, this work demonstrated a new strategy for simultaneously removing toluene and NO with free-ammonia under the photothermocatalysis system based on UV light irradiation.