The enhanced piezoelectric field induced by self-polarization promotes hydrogen evolution reaction on g-C3N4/MoO3/PVDF-TrFE membrane under low-speed water flow

The piezoelectric properties are closely related to the properties of photocatalytic membrane in water environment. Here, a self-polarized g-C 3 N 4 /MoO 3 /PVDF-TrFE membrane with high piezoelectricity was synthesized using a facile spin-coating strategy. In the presence of a low-speed water flow, a stabilized photocatalytic hydrogen evolution rate (538.8 µmol g -1 h −1 ) was obtained for the g-C 3 N 4 /MoO 3 /PVDF-TrFE membrane. Experimental results revealed that the g-C 3 N 4 /MoO 3 induced a reorganization of PVDF-TrFE structure and thereby enlarged the polarization electric field to promote the directional migration of charge carriers and exciton dissociation. Additionally, pressure current test demonstrated that under the same pressure conditions, g-C 3 N 4 /MoO 3 /PVDF-TrFE exhibited a higher response than PVDF-TrFE. This work establishes a new method for the polarization electric field and provides a deeper understanding of the hydrogen evolution mechanism.