2-propanol photodegradation over molybdates: effects of chemical compositions and electronic structures

A new kind of photocatalysts, ABi(MoO4)2 (A = Na, Ag), were prepared by a traditional solid-state reaction method. The samples were characterized by x-ray diffraction, UV–Vis diffuse reflectance spectroscopy, N2 adsorption–desorption measurement and scanning electron microscopy. The results showed that ABi(MoO4)2 (A = Na, Ag) were all crystallized in a tetragonal system with the space group I41/a. However, the substitution of A 1+ cations with different elemental compositions imposed significant effects on their electronic structures and photocatalytic performance. The photocatalytic activities were evaluated by photo-oxidation of gaseous 2-propanol. It was found that NaBi(MoO4)2 showed a higher activity than AgBi(MoO4)2. Theoretically, calculated band structures and density of states by the plane-wave density functional theory revealed that the different photophysical and photocatalytic properties of ABi(MoO4)2 (A = Na, Ag) can possibly be ascribed to their different electronic structures.