Enhanced photocatalytic degradation of bisphenol A by a novel donor–acceptor g-C3N4: π-π interactions boosting the adsorption and electron transfer behaviors

The interaction and electron transfer between pollutant molecules and photocatalysts are critical to the degradation process but has been rarely studied. In the present contribution, donor–acceptor (D-A) type graphitic carbon nitride (g-C3N4) with expanded π-conjugated system are elaborately prepared. The removal efficiency of bisphenol A (a typical endocrine disruptor) by the optimal sample is 2.9 times as that of pure g-C3N4. Based on the experimental results and DFT calculation, it is found that the formed charge transfer channels in D-A g-C3N4 substantially promote the spatial separation and transfer efficiency of photogenerated charges. Besides, the expanded π-conjugated system improves light absorption ability, enhances the π-π interactions between catalysts and pollutant molecules (facilitating the adsorption and electron transfer). This study provides a new idea for photocatalysis to achieve efficient environmental remediation, that is the adsorption and electron transfer of pollutants in the degradation process should be further considered while modifying the photocatalysts.