Dual-defect enhanced piezocatalytic performance of C3N5 for multifunctional applications

An effective piezocatalytic semiconductor (C3N5-x-O) was prepared with a two-step thermal polymerization/ etching method. Experimental characterizations and structural simulations revealed that the dual-defects of O doping and N vacancy in C3N5 not only increases the asymmetry and the exposure of triangular pores, but also optimizes the band structure and charge distribution of the thin-layered C3N5-x-O, endowing it with an enhanced piezoelectricity and increased active surfaces. Piezocatalysis-mediated pollutant degradation and H2O2 pro-duction were achieved with substantially improved efficiencies over the pristine carbon nitrides. Under ultrasound-assisted piezocatalysis, tetracycline was degraded with a kinetic rate of 0.0356 min-1 and this figure was further increased to 0.0561 min-1 in piezocatalytic-Fenton. A yield of 0.615 mM/g/h for piezocatalytic production of H2O2 was achieved in pure water. The synergistic effect of the defect sites revealed in present work could facilitate the more rational design of nitrogen-rich carbon nitrides for environmental remediation and the production of value-added chemicals.

Automated summary

An effective piezocatalytic semiconductor (C3N5-x-O) was prepared using a two-step thermal polymerization/etching method. The dual-defects of O doping and N vacancy in C3N5 increased the material's asymmetry and exposure, optimized the band structure and charge distribution, and enhanced its catalytic performance.