Sn-bridge type-Ⅱ PCN/Sn/SnO heterojunction with enhanced photocatalytic activity

摘要

The porous g-C3N4(PCN)/Sn/SnO ternary type-II heterojunction photocatalyst was synthesized by simple heat treatment combined with photodeposition. The results of a series of characterizations displayed that, with an electronic bridge structure, the type-II heterojunction photocatalyst has been successfully prepared. In the presence of PCN/Sn/SnO, RhB was degraded entirely in 40 min, and the conversion and selectivity of benzylamine oxidative reaction reached 99.9% within 6 h. The enhanced photocatalytic activity of PCN/Sn/SnO is attributed to high specific surface area and the metallic Sn(0)acting as electron bridges at the interface between SnO and PCN, which can accelerate the speed of photogenerated electrons transmission and inhibit recombination of photogenerated electron-hole pairs. After five cycles of operation, PCN/Sn/SnO maintained high photocatalytic activity. A reasonable photocatalytic reaction pathway was proposed via the free radical quenching test and mechanism analysis.