Abstract:

In this study, the electronic structures and photocatalytic properties of Ag₃XO₄ (X = P, As, V) were investigated using the first principles based on the density functional theory. In comparison to Ag₃PO₄, Ag₃VO₄ shows better photocatalytic stability, mainly due to the enhanced Ag―O bonds and improved Ag ion stability, but poorer photocatalytic activity in the visible light region mainly due to the presence of d orbital character at the conduction band minimum (CBM) and lower valence band maximum (VBM) potentials (2.335 V, vs NHE). Ag₃AsO₄ shows photocatalytic activity superior to Ag₃PO₄, which may be attributed to the following reasons: (1) the highly dispersive band structure of the CBM resulting fromAg s-Ag s hybridization, (2) a smaller band gap of 1.91 eV, (3) the broader absorption range and higher absorption capacity of visible light. Moreover, our theoretical results demonstrate that though Ag₃XO₄ (X = P, As, V) species act as indirect band gap photocatalytic semiconductors, only Ag₃VO₄ is a potential candidate for the photocatalytic hydrogen generation from water. The calculated results mentioned above are in good agreement with experimental results.

Key words: First principles calculations, Ag₃XO₄ (X = P, As, V), Band structure, Density of states, Photocatalytic property