空位氧化铋/多壁碳纳米管复合催化剂低温热催化杀菌性能研究

Low-temperature thermal catalytic disinfection performance by vacancy-rich bismuth oxides/multi-walled carbon nanotube composite

低温热催化杀菌技术具有优异的杀菌效率和良好的经济性,是具有应用潜力的灭菌方法.本文首先通过一步水热法合成了空位氧化铋(BiO_(2)-x)材料,同时将多壁碳纳米管(CNTs)进行酸化处理,之后将两者通过自组装的策略复合获得BiO_(2)-x/CNTs复合催化剂.采用XRD、FT-IR、SEM、XPS、电流响应及电化学阻抗分析等手段对所得BiO_(2)-x/CNTs催化剂进行表征,分析其物化特性.与BiO_(2)-x相比,BiO_(2)-x/CNTs有着更高的电荷分离和迁移效率,CNTs比例为15%的BiO_(2)-x/CNTs复合催化剂有着最佳的热催化杀菌效率,在2 h内,55℃条件下,可杀灭5.42 lg·cfu·mL^(-1)的大肠杆菌(E.coli K-12).自由基猝灭剂的实验结果表明,·OH(羟基自由基)、^(1)O_(2)(单线态氧)和·O_(2)-(超氧自由基)是BiO_(2)-x/CNTs热催化作用于E.coli K-12的主要活性物种.

Low temperature thermal catalytic technology is an alternative sterilization method due to its disinfection and cost effective.In this work,vacancy-rich bismuth oxides(BiO_(2)-x)was first synthesized by one-step hydrothermal method,and acid treatment of multi-walled carbon nanotubes(CNTs)was produced.Afterwards,BiO_(2)-x/CNTs composite catalyst was achieved via self-assembly strategy by employing BiO_(2)-x and CNTs.The obtained catalysts were characterized by Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD),scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),current response,electrochemical impedance spectroscopy(EIS),etc.,which was used to analyze the physicochemical properties.Compared with BiO_(2)-x,BiO_(2)-x/CNTs had higher charge separation and migration efficiency.When the mass ratio of CNTs and BiO_(2)-x reached 15%,BiO_(2)-x/CNTs-15 sample showed optimum thermal disinfection efficiency.The result demonstrated that the 5.42 lg·cfu·mL^(-1) of Escherichia coli K-12(E.coli K-12)could be disinfected within 2 h at 55℃.The results of free radical quenching studies illustrated that(·OH)hydroxyl radical,1O_(2)(singlet oxygen)and·O_(2)-(superoxide radical)were the main active species during the thermal catalytic sterilization of E.coli K-12 over BiO_(2)-x/CNTs-15.