Porous carbon nitride nanosheets for enhanced photocatalytic activities

Abstract

Porous carbon nitride nanosheets (PCNs) have been prepared for the first time by a simple liquid exfoliation method via probe sonication. These mesoporous nanosheets of around 5 nm in thickness combine several advantages including high surface area, enhanced light absorption and excellent water dispersity. It can be used as a versatile support for co-catalyst loading for photocatalytic dye degradation and water reduction. With 3.8 wt% Co₃O₄ loaded, PCNs can achieve more efficient photocatalytic degradation of Rhodamine B, compared with non-porous C₃N₄ nanosheets (CNs), bulk porous C₃N₄ (PCN) and bulk nonporous C₃N₄ (CN). With 1.0 wt% Pt loaded, CNs and PCN exhibit 7–8 times enhancement in H₂ evolution than CN. Remarkably, PCNs with both porous and nanosheet-like features achieve 26 times higher activity in H₂ evolution than CN. These significant improvements in photocatalytic activities can be attributed to the high surface area as well as better electron mobility of the two-dimensional nanostructure.