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

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 degrees 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.