Low Temperature Part Per Billion H₂S Sensor Based on P-N CuO-WO₃ Heterostructured Microflowers

Hydrogen sulfide (H₂S) is a common environmental pollutant and a biomarker for gas detection in a variety of diseases. The development of a fast and low parts per billion level H₂S gas sensor is of great significance for environmental monitoring and the development of smart medical treatment. In this study, CuO composite WO₃ nanofloral materials were synthesized by the hydrothermal method, and p-n heterostructures were successfully constructed. The gas-sensitive performance test results show that the response value of 20 wt % CuO/WO₃ sensor to 10 ppm of H₂S gas at 60 °C is as high as 3511.1, the response time is only 4 s, and the detection limit is as low as 1 ppb. In addition, it also has the characteristics of a wide detection range, good linearity, and good selectivity. The nanoflower structure of the multigas dispersion channel, the construction of p-n heterojunction, and the sulfurization effect of H₂S on CuO enable the sensor to detect H₂S at the ppb level at low temperature.