Construction of LaF3 QD-modified SnS2 nanorod composites for ultrasensitive detection of H2S

Abstract

The rapid detection of low-concentration H₂S gas is of great significance to ensure the normal operation of SF₆ electrical insulation equipment. Here, a sensitive material made of LaF₃ QD modified SnS₂ nanorods was prepared for the detection of H₂S gas. The sensor has an optimal operating temperature of 150 °C and exhibits excellent stability, moisture resistance, selectivity, and long-term stability. The response value of the sensor to 30 ppm was 85.2%, and the response and recovery times were 4 s and 93 s, respectively. First-principles calculations showed that LaF₃ QDs enhance the adsorption of H₂S by SnS₂, and further described the interaction mechanism between LaF₃–SnS₂ and H₂S. The greatly improved performance of 15% LaF₃–SnS₂ can be attributed to the sensitization synergistic effect and heterojunction effect of QDs. A H₂S detection circuit based on a 15% LaF₃–SnS₂ sensor was constructed, and the real-time display and alarm functions of the concentration were realized. The H₂S sensor prepared with 15% LaF₃–SnS₂ is expected to be a sensing device for detecting SF₆ electrical insulation equipment.