Experimental study on inactivation of <i>Escherichia coli</i> by atmospheric pressure non-equilibrium plasma combined with photocatalysis

摘要： In order to improve the sterilization effect and energy efficiency of atmospheric pressure non-equilibrium plasma (APNP), a synergistic treatment system of APNP combined with photocatalysis was established to inactivate Escherichia coli. TiO2 is selected as the photocatalyst. The colony counting result indicates that APNP treatment combined with photocatalysis has an enhancement effect on sterilization. The enhancement factor η is up to 80.2%. The SEM images show that 30 s APNP treatment combined with photocatalysis causes greater structural damage than traditional APNP treatment. The discoloration photometric suggests that up to 120% more ROS are produced in APNP combined with photocatalysis. Optical emission spectra show that photocatalysis leads to weakening of the ionization process and thus weakens the plasma discharge. In accordance with the infrared thermal images, temperature rise in APNP combined with photocatalysis is 4 °C lower than that in traditional APNP treatment, which may enlarge the application area of biomedical field.