Piezoelectric nanofoams with the interlaced ultrathin graphene confining Zn–N–C dipoles for efficient piezocatalytic H2 evolution under low-frequency vibration

Unique nanofoams consisting of interweaved ultrathin graphene confining Zn–N–C dipoles (ZnNG) are constructed via calcination of Zn-coordinated precursor. Due to the introduction of local polar Zn–N–C configurations, with hypersensitivity for mechanical stress, the piezoelectricity is created on the nonpiezoelectric graphene, and the hierarchical ZnNG exhibits obvious piezocatalytic activity of water splitting for H2 production even under mild agitation. The corresponding rate of H2 production is about 14.65 μmol g−1 h−1. It triggers a breakthrough in piezocatalytic H2 evolution under low-frequency vibration, and takes a significant step forward for piezocatalysis towards practical applications. Furthermore, the presented concept of confining atomic polar configuration for engineering piezoelectricity would open up new horizon for constructing new-type piezoelectrics based on both piezoelectric and nonpiezoelectric materials.