Wet-chemistry synthesis of shape-controlled Ag3PO4 crystals and their 3D surface reconstruction from SEM imagery

Rapid Synthesis Method of Ag3PO4 as Reusable Photocatalytically Active Semiconductor

The widespread use of Ag₃PO₄ is not surprising when considering its higher photostability compared to other silver-based materials. The present work deals with the facile precipitation method of silver phosphate. The effects of four different phosphate sources (H₃PO₄, NaH₂PO₄, Na₂HPO₄, Na₃PO₄·12 H₂O) and two different initial concentrations (0.1 M and 0.2 M) were investigated. As the basicity of different phosphate sources influences the purity of Ag₃PO₄, different products were obtained. Using H₃PO₄ did not lead to the formation of Ag₃PO₄, while applying NaH₂PO₄ resulted in Ag₃PO₄ and a low amount of pyrophosphate. The morphological and structural properties of the obtained samples were studied by X-ray diffractometry, diffuse reflectance spectroscopy, scanning electron microscopy, infrared spectroscopy, and X-ray photoelectron spectroscopy. The photocatalytic activity of the materials and the corresponding reaction kinetics were evaluated by the degradation of methyl orange (MO) under visible light. Their stability was investigated by reusability tests, photoluminescence measurements, and the recharacterization after degradation. The effect of as-deposited Ag nanoparticles was also highlighted on the photostability and the reusability of Ag₃PO₄. Although the deposited Ag nanoparticles suppressed the formation of holes and reduced the degradation of methyl orange, they did not reduce the performance of the photocatalyst.

Unraveling the relationship between exposed surfaces and the photocatalytic activity of Ag3PO4: an in-depth theoretical investigation

Over the years, the possibility of using solar radiation in photocatalysis or photodegradation processes has attracted remarkable interest from scientists around the world. In such processes, due to its electronic properties, Ag₃PO₄ is one of the most important semiconductors. This work delves into the photocatalytic activity, stability, and reactivity of Ag₃PO₄ surfaces by comparing plane waves with projector augmented wave and localized Gaussian basis set simulations, at the atomic level. The results indicate that the (110) surface, in agreement with previous experimental reports, displays the most suitable characteristics for photocatalytic activity due to its high reactivity, i.e. the presence of a large amount of undercoordinated Ag cations and a high value work function. Beyond the innovative results, this work shows a good synergy between both kinds of DFT approaches.