Abstract
Zeolite imidazole skeleton(ZIF-8)is a promising option for self-cleaning of building exterior walls due to its large specific surface area,high antibac-terial activity and low biotoxicity.However,it suffers from low antibacterial efficiency and yield under visible light irradiation.To address the issues,we developed the pho-tocatalytic materials T-ZIF-8-TDI(thermally treated-ZIF-8-toluene 2,4-diisocyanate)by modifying ZIF-8 with thermal oxygen sensitization and chemical bonding.The results show that the yield of T-ZIF-8-TDI photocatalytic antibacterial agent is increased to 11.5 times of that of T-ZIF-8,while maintaining the crystal structure of T-ZIF-8 and thermal stability up to 60 ℃.Furthermore,T-ZIF-8-TDI exhibits extended optical response range to the near-infrared region,significantly narrowed band gap,improved photogenerated electron-hole separation efficiency,reduced recombination rate,and excellent photocatalytic performance.When the concentration of antibacterial agent is 600 mg·L-1,the antibacterial rate of Escherichia coli(E.coli)reaches 99.99%irradiated by visible light for 30 min,and when the concentration of antibacterial agent is 200 mg·L-1,the antibacterial rate of Staphylococcus aureus(S.aureus)reaches 99.99%irradiated by visible light for 25 min.We also analyzed the reasons in detail from the aspects of bacterial species and antibacterial mechanism,and proposed the antibacterial mechanism of·O2-and h+as the main active species.These findings suggest that T-ZIF-8-TDI photocatalytic antibacterial agent has potential for use in self-cleaning of building exterior walls.
基金项目
Projects of the Research and Development Project of New Materials and Chemical Engineering Research Institute of Shanxi Zhej(2021SX-AT010)
国家自然科学基金(21972103)
Innovation and Entrepreneurship Training Program for College Students(202110112012)