Micro-spherical SnO2/Zn2SnO4 heterojunction for sensitive and selective detection of hydrogen sulfide

Detecting hydrogen sulfide (H2S) with high performance is crucial in various applications, particularly in breath diagnostics. Ternary metal oxide materials with appropriate structures are seen as promising for precise and sensitive gas detection. In this study, a composite material of Zn2SnO4/SnO2 with different crystal shapes was created using a one-step co-precipitation method by adjusting the precursor ratio. Among these, the micro-spherical Zn2SnO4/SnO2 composite displayed the smallest size, largest specific surface area, and highest pore volume. Gas sensors utilizing this material exhibited effective response and recovery to H2S concentrations ranging from 0.2 to 25 ppm. Notably, a response value of 1850 was achieved for 1 ppm H2S at a relatively low operating temperature of 160℃. Additionally, the sensor demonstrated exceptional selectivity (selectivity coefficient ≥185), repeatability, and long-term stability. This type of gas sensor holds significant potential for applications in breath analysis and disease diagnosis.