Nanoarchitecturing TiO/NiCrO p-n heterojunction photocatalysts for visible-light-induced activation of persulfate to remove tetracycline hydrochloride.

Herein, TiO/NiCrO nanocomposites with p-n heterojunctions were synthesized via a refluxing method and used with peroxydisulfate (PDS) to produce extensive reactive radicals. Textural, optical, photoelectrochemical, structural, and morphological properties of the prepared materials were extensively investigated. After adding 1.48 mM PDS, the removal rate constant of tetracycline hydrochloride (TH) over the TiO/NiCrO (20%)/PDS system was almost 20.5, 7.24, and 5.91-times as high as the pristine TiO, TiO/PDS, and TiO/NiCrO (20%) samples, respectively. Therefore, the synergistic effect of PDS and heterogeneous photocatalysis remarkably impacted the degradation reaction of TH. It was proposed that all h, O, OH, and SO contributed to the degradation reaction. According to the formation of heterojunction between n-TiO, and p-NiCrO semiconductors, a plausible mechanism for removal of different contaminants in the TiO/NiCrO/PDS system was discussed.