Insights Into Highly Improved Solar-Driven Photocatalytic Oxygen Evolution Over Integrated Ag(3)PO(4)/MoS(2) Heterostructures

Oxygen evolution has been considered as the rate-determining step in photocatalytic water splitting due to its sluggish four-electron half-reaction rate, the development of oxygen-evolving photocatalysts with well-defined morphologies and superior interfacial contact is highly important for achieving high-performance solar water splitting. Herein, we report the fabrication of Ag(3)PO(4)/MoS(2) nanocomposites and, for the first time, their use in photocatalytic water splitting into oxygen under LED light illumination. Ag(3)PO(4) nanoparticles were found to be anchored evenly on the surface of MoS(2) nanosheets, confirming an efficient hybridization of two semiconductor materials. A maximum oxygen-generating rate of 201.6 μmol · L(−1) · g(−1) · h(−1) was determined when 200 mg MoS(2) nanosheets were incorporated into Ag(3)PO(4) nanoparticles, which is around 5 times higher than that of bulk Ag(3)PO(4). Obvious enhancements in light-harvesting property, as well as electron-hole separation and charge transportation are revealed by the combination of different characterizations. ESR analysis verified that more active oxygen-containing radicals generate over illuminated Ag(3)PO(4)/MoS(2) composite photocatalysts rather than irradiated Ag(3)PO(4). The improvement in oxygen evolution performance of Ag(3)PO(4)/MoS(2) composite photocatalysts is ascribed to wide spectra response in the visible-light region, more efficient charge separation, and enhanced oxidation capacity in the valence band (VB). This study provides new insights into the design and development of novel composite photocatalytic materials for solar-to-fuel conversion.