Efficient degradation of norfloxacin by CoWO4/CS/BiOCl-10 Z-type heterojunction photocatalysts based on hydrogen bonding and interfacial interaction

In this study, a Z-type heterojunction photocatalyst CoWO 4 /CS/BiOCl-10 was constructed by hydrothermal synthesis for the efficient removal of norfloxacin (NOR) contaminants in water. X-ray photoelectron spectroscopy (XPS) combined with Fourier transform infrared spectroscopy (FT-IR) confirmed that the hydroxyl group in the chitosan (CS) molecule was bonded with the oxygen atom on the surface of CoWO 4 through hydrogen bonding to form a directional charge transport channel, which greatly improved the photocatalytic degradation efficiency of CoWO 4 /CS/BiOCl-10, and the degradation rate was as high as 98.30 % within 90 min under 300 W xenon lamp irradiation. Optoelectronic measurements show that the interfacial potential difference drives electrons to migrate along the Z-path. Density functional theory (DFT) and liquid chromatography-mass spectrometry (LC-MS) were used to identify intermediates in the NOR degradation process, revealing the degradation pathway of NOR through piperazine ring cleavage and defluorination. The kinetics of NOR degradation intermediates were revealed using two-dimensional correlation spectroscopy (2DCOS) techniques. Rice seed germination experiments have shown that the degraded NOR solution is virtually non-toxic, greatly reducing the environmental impact. This study provides a new strategy for the development of efficient photocatalytic systems through the synergistic regulation mechanism of hydrogen bonding and heterojunction.