Light¬¬¬-activation of the gas sensitivity of ZnO nanorods to reduce the operating temperature of sensors

A study of sensor coatings based on zinc oxide nanorods with activation of gas sensitivity to isopropyl alcohol vapor by irradiation in the ultraviolet and visible regions of the spectrum is presented. It is shown that irradiation with an ultraviolet LED with a peak wavelength of 370 nm ensures the gas sensitivity of the sensor coating to isopropyl alcohol vapor at room temperature. Reducing the power consumption of the LED to 100 mW by increasing the duty cycle of the supplied voltage at a pulse period of 2 ms leads to an insignificant decrease in sensitivity. It has also been shown that the combination of heating up to 150°C with ultraviolet irradiation of the sensor coating leads to an increase in response. To activate gas sensitivity in the visible range, zinc oxide nanorods were decorated with colloidal AgInS2 quantum dots. It has been shown that zinc oxide and colloidal AgInS2 quantum dots with a shell of mercaptopropionic acid form a heterojunction, and decoration of zinc oxide nanorods with colloidal quantum dots provides sensitization of zinc oxide to irradiation in the visible region. Sensitization of ZnO nanorods with colloidal AgInS2 quantum dots provided gas sensitivity to isopropyl alcohol vapor at room temperature under illumination with a peak wavelength of 460 nm.