Facet Effects of Ag3 PO4 on Charge-Carrier Dynamics: Trade-Off Between Photocatalytic Activity and Charge-Carrier Lifetime.

Silver phosphate (Ag3 PO4 ) is a promising visible-light-driven photocatalyst with a strong oxidation power and exceptionally high apparent quantum yield of O2 evolution. Although engineering Ag3 PO4 facets is widely known to enhance its photocatalytic activity, most studies have explained its facet effect by calculating surface energies. Herein, the charge carrier dynamics in three kinds of Ag3 PO4 crystals (mixed facets, cubic, and tetrahedral structures) were first investigated using single-particle photoluminescence microscopy and femtosecond time-resolved diffuse reflectance spectroscopy. As a result, we clarified that the disagreement between the photocatalytic activities (dye degradation and O2 evolution) of different Ag3 PO4 facets are the consequence of trade-off between catalytic activity and lifetime of photogenerated charge carriers in addition to surface energy.