Fabrication of RuO_2-Ag_3PO_4 heterostructure nanocomposites: Investigations of band alignment on the enhanced visible light photocatalytic activity

摘要

Graphical abstractDisplay OmittedHighlights•Ag3PO4, RuO2and RuO2-Ag3PO4heterostructure nanocomposites were prepared using simple wet chemical technique.•The electric field at interface of pure Ag3PO4and RuO2-Ag3PO4is found to be 310mV.•RuO2-Ag3PO4inhibits self oxidation of Ag3PO4under this formed electric field.•The enhanced electrons-holes separation leads the higher efficiency as well as stability for RuO2-Ag3PO4.AbstractThe RuO2-Ag3PO4heterostructured nanocomposite was successfully synthesized by facile in situ deposition of porous ruthenium oxide (RuO2) nanoparticles on the surface of the silver phosphate (Ag3PO4). Under visible light irradiation, the 0.5wt.% RuO2-Ag3PO4heterostructure photocatalyst exhibits enhanced photocatalytic efficiency compared to other composites of RuO2-Ag3PO4and Ag3PO4. The optimized 0.5wt.% RuO2-Ag3PO4nanocomposites exhibited 1.5 times enhanced photocatalytic activity towards the degradation of methylene blue (MB) than Ag3PO4. Moreover, the degradation rate of 0.5wt.% RuO2-Ag3PO4nanocomposite towards the cationic dyes MB and rhodamine B (RhB) was nearly 6.6 times and 4.7 times higher than that towards the anionic dye methyl orange (MO). The formed heterojunction electric field of 310mV at the interface between RuO2and Ag3PO4heterostructure induces downward band bending of Ag3PO4. Also, this electric field increases the separation efficiency of electrons-holes resulting higher degradation efficiency. The quenching effect of scavengers test confirms that holes are reactive species and the RuO2-Ag3PO4nanocomposite is highly stable, exhibited 88% of MB degradation after 4 recycles. The RuO2-Ag3PO4nanocomposites inhibit self oxidation of Ag3PO4resulting improved efficiency and stability.