Synergetic photocatalytic and piezocatalytic degradation of organic pollutants over graphite carbon nitride

Environmental pollution has become an imminent problem for the healthy and sustainable development of human society. Although photocatalytic degradation of organic pollutants over semiconductors was recognized as a promising strategy to resolve this problem, the degradation activity of most of photocatalysts was unsatisfactory owing to the rapid recombination of photogenerated electron-hole pairs. In this work, significantly enhanced degradation performance for RhB organic dye over graphite carbon nitride (g-C3N4) photocatalyst were demonstrated, resulting from the synergetic photocatalytic and piezocatalytic effects. The photocatalytic and piezocatalytic degradation properties of g-C3N4 photocatalyst and the influence of nitrogen defects on them were investigated respectively. With the synergetic functions of light irradiation and mechanical vibration, the synergistic degradation performance is significantly greater than the sum of single photocatalysis and piezocatalysis owing to the recombination of photogenerated carries could be inhibited effectively by the created piezoelectric field in g-C3N4 nanosheets. These findings proved that the coupling of photocatalytic and piezocatalytic properties of semiconductors opens a new gateway to remove organic contaminants.