SiC/g-C3N4 (SCN) was synthesized to inactivated the resistant bacteria; and the binding of SiC to g-C3N4 was simply determined by FT-IR. Plasmid pET-28a(+) carrying kanamycin resistance was transformed into the competence of Escherichia coli (E. coli), and its positive bacteria was used as the object of photocatalytic inactivation. Catalytic conditions were optimized, under which the bactericidal kinetics and reuse of the materials were studied. The photoelectric reaction and light absorption were studied by electrochemical workstation and UV-vis DRS. In addition, potassium dichromate (Cr6+), isopropanol (IPA), methanol (MTA), sodium oxalate (Na2C2O4) and 4-hydroxy-2, 2, 6, 6-tetramethylpiperidinyloxy (TEMPOL) were used to study the photocatalytic mechanism. FT-IR results showed that SCN was successfully synthesized, and the positive E. coli was obtained. Under optimal inactivation conditions, SCN had good reusability. Photoelectric experiments showed that the photogenerated electrons (e-) and holes (h+) were more easily separated, and SCN has a larger spectral absorption range and a lower band gap. According to the kinetic study, SCN and g-C3N4 had great advantages in sterilization efficiency. Mechanism study showed that e-, h+, hydrogen oxygen radicals (·OH) and superoxide radicals (·O2-) were generated in the photocatalytic process, and ·O2- played the most important roles in inactivation.
Wenming Jiang, Chaoxia Wang, Rujira Sukhotu, Shiyang Zhou, Ying Yuan, Le Li and Jingjing Yang