H(2)O(2) rejuvenation-mediated synthesis of stable mixed-morphology Ag(3)PO(4) photocatalysts

Ag(3)PO(4) photocatalyst has attracted interest of the scientific community in recent times due to its reported high efficiency for water oxidation and dye degradation. However, Ag(3)PO(4) photo-corrodes if electron accepter such as AgNO(3) is not used as scavenger. Synthesis of efficient Ag(3)PO(4) followed by a simple protocol for regeneration of the photocatalyst is therefore a prerequisite for practical application. Herein, we present a facile method for the synthesis of a highly efficient Ag(3)PO(4), whose photocatalytic efficiency was demonstrated using 3 different organic dyes: Methylene Blue (MB), Methyl orange (MO) and Rhodamine B (RhB) organic dyes for degradation tests. Approximately, 19 % of Ag(3)PO(4) is converted to Ag(0) after 4.30 hours of continuous UV-Vis irradiation in presence of MB organic dye. We have shown that the Ag/Ag(3)PO(4) composite can be rejuvenated by a simple chemical oxidation step after several cycles of photocatalysis tests. At an optimal pH of 6.5, a mixture of cubic, rhombic dodecahedron, nanosphere and nanocrystals morphologies of the photocatalyst was formed. H(2)O(2) served as the chemical oxidant to re-insert the surface metallic Ag into the Ag(3)PO(4) photocatalyst but also as the agent that can control morphology of the regenerated as-prepared photocatalyst without the need for any other morphology controlling Agent (MCA). Surprisingly, the as- regenerated Ag(3)PO(4) was found to have higher photocatalytic reactivity than the freshly made material and superior at least 17 times in comparison with the conventional Degussa TiO(2), and some of TiO(2) composites tested in this work.