Silver phosphate-based Z-Scheme photocatalytic system with superior sunlight photocatalytic activities and anti-photocorrosion performance

The serious photocorrosion of silver phosphate (Ag3PO4) has limited its practical applications. In this work, we propose a strategy to suppress its photocorrosion by the construction of a Z-Scheme photocatalytic system, which composed of reduced graphene oxide-enwrapped Ag3PO4 (Ag3PO4@RGO) and La,Cr-codoped SrTiO3 (La,Cr:SrTiO3). Dramatically, this system shows superior anti-photocorrosion and photocatalytic performances in degradation of both RhB and 2,4-DNP. Especially for RhB, it can be completely degraded after only 5 min under intense sunlight irradiation. The improved photoactivity and anti-photocorrosion of Ag3PO4@[email protected],Cr:SrTiO3 can be attributed to the following: (i) The sufficient interfacial contact between Ag3PO4 and RGO is favorable to transfer the carriers and lengthen the lifetime of it; (ii) the package of Ag3PO4 with RGO could work as a sheltering layer to protect Ag3PO4 from photocorrosion. (iii) The aggregation of photogenerated holes in the VB of Ag3PO4 makes it a rich-hole region due to Z-Scheme electrons transport mechanism, which can protect Ag3PO4 from the photo-reduction. This strategy provides a new thought of protecting photosensitive semiconductor from photocorrosion and could regard as an efficient application method for environmental cleaning under natural sunlight irradiation. Furthermore, it even could be extended to outdoor or indoor air cleaning in the future.