Piezocatalytic performance difference of graphitic carbon nitride (g-C3N4) derived from different precursors

Four types of g-C3N4 materials were prepared with thiourea, urea, melamine and dicyandiamide as precursors. The differences of their piezocatalytic performance were studied in detail and the mechanism of piezocatalytic degradation of RhB was analyzed. [Display omitted] •g-C3N4 with different piezocatalytic performance derived from variable precursors was studied.•N defects can destroy asymmetric structure of g-C3N4 then reduce the piezocatalytic performance.•The sheet structure with low stacking degree is conducive to the occurrence of piezocatalytic effect.••OH play a major role in the degradation of pollutants over g-C3N4 piezocatalysis. In this paper, four types of graphitic carbon nitride (g-C3N4) are prepared from different precursors by thermal polycondensation method and the piezocatalytic performance difference of the obtained g-C3N4 materials are investigated in detail. g-C3N4 derived from thiourea delivers best piezocatalytic performance basing on KMnO4 reduction experiment and rhodamine B degradation experiment. According to the differences of piezocatalytic performance of these g-C3N4 materials, effects of morphology, composition and defects on piezocatalytic performances are discussed. Reactive oxygen species (ROS) capture experiment showed that g-C3N4 could produce ROS through piezoelectric effect and hydroxyl radical (•OH) played a major role in pollutant degradation.