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The photocatalytic activity of TiO 2 and manganese doped TiO 2 nanoplates with various manganese atomic percentages, in the range of 2–7%, was studied. The undoped and doped nanoplates with exposed {0 0 1} facets were produced by a solvothermal method. The crystal structure as well as the shape of the TiO 2 and Mn 4+ /TiO 2 anatase nanoparticles was determined with X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). Both techniques revealed that the nanocrystals are in the form of plates. Moreover, the anisotropic peak broadening of the X-ray diffraction patterns was studied using the Rietveld refining method. Chemical analysis of the photocatalyst that was carried out with X-ray photoelectron spectroscopy (XPS) showed the presence of manganese ions in the TiO 2 anatase matrix. The Density Functional Theory (DFT) calculations exhibited a decrease in the energy gap and an increase in the density of the electronic stated inside the gap for the doped TiO 2. These observations were in agreement with the results of the UV–visible diffuse reflectance spectroscopy (DRS) that demonstrated an adsorption shift towards the visible region for the same samples. The photocatalytic activity of the synthesized catalysts was investigated by the photocatalytic oxidation of the gaseous nitric oxide (NO) and decomposition of the gaseous acetaldehyde (CH 3 CHO) under visible light irradiation. The optimal concentration of dopant that improves the photocatalytic activity of the nanoplates was determined. [ABSTRACT FROM AUTHOR]

Highlights: [•] Ag nanoparticles exclusively photodeposited on the {101} anatase crystal facets. [•] The photodeposition irradiation time tuned the size of the Ag nanoparticles. [•] The size of the Ag nanoparticles affected photocatalytic activity of the samples. [•] Ag decorated nanoplates have high activity for NO oxidation and NO x removal. [Copyright &y& Elsevier]

Highlights: [•] Mg2+ doped anatase nanoplates with {001} facets were prepared by solvothermal method. [•] Mg2+ doping leads to vertically piling up of nanoplates creating large microcrystals. [•] Magnesium doping shifts the absorption edge of TiO2 towards visible light region. [•] Low Mg2+ doping enhances the photocatalytic activity for air pollutants oxidation. [ABSTRACT FROM AUTHOR]

Highlights: [•] Anatase nanoplates with large {001} facets prepared by solvothermal method. [•] Calcination of anatase nanoplates led to crystal shape with larger {101} facets. [•] Altering anatase crystal habit enables selectivity in air pollutants oxidation. [•] Anatase nanoplates with dominant {001} facets favour decomposition of acetaldehyde. [•] Anatase with dominant large {101} crystal facets favours the NO oxidation. [ABSTRACT FROM AUTHOR]