π-π conjugation driving degradation of aromatic compounds with in-situ hydrogen peroxide generation over Zn2In2S5 grown on nitrogen-doped carbon spheres

The water contaminant control with the simultaneous production of clean energy has been considered an ideal and sustainable strategy. Herein, a self-assembled Zn2In2S5 with N-doped hollow carbon spheres (NHCS) was first synthesized via in-situ hydrothermal method to achieve excellent performance for aromatic pollutant removal with high amounts of H2O2 formed. Such a composite harvested phenol degradation efficiency of 97.6% with high H2O2 yield of 1.31 mmol L-1, and bisphenol A (BPA) degradation efficiency of 79.7% with high H2O2 yield of 2.31 mmol L-1. In addition, in-situ produced H2O2 solution of composites achieved high-efficiency bacterial inactivation. Based on the characterization results, NHCS contained abundant aromatic frameworks of pi conjugates with C-C and N-hybrid rings. Meanwhile, phenol or BPA with rich pi bonds was tightly adsorbed to the photocatalyst surface through pi-pi interactions, which resulted in decreased activation energy with surface adsorbed phenol*/BPA* . The obtained electrons were quickly transferred to the dispersed dissolved oxygen accompanied by promoting the reduction of O-2 into H2O2. This synergetic process was expected to develop novel photocatalysts towards water disinfection achieved the reuse of wastewater.