Long-term and stable detection of H₂S in a pig house at low operating temperature based on Ce₂O₃/In₂O₃ hollow microspheres with a remote monitoring system

A remote system for real time monitoring of H₂S in a pig house combining with a new type of gas sensor fabricated via Ce₂O₃/In₂O₃ hollow microspheres (HMS) was successfully built. The microstructure and morphology of the microspheres and their gas sensing performance were investigated in detail. At optimal operating temperature (100 ℃), the Ce₂O₃/In₂O₃ HMS composite exhibited excellent sensing properties towards H₂S, which afforded a linear response range from 0.10 to 100 ppm with a detection limit of 0.06 ppm and a short response time of 59 s. Compared with In₂O₃ based sensor, the Ce₂O₃/In₂O₃ HMS sensor presented not only low power consumption for efficient energy-saving, but also even high response ability. After 10 months of continuous monitoring of H₂S gas in pig farm via Alibaba Cloud transmission network, only 5.4% of the sensor's response attenuated was found, indicating that the HMS based sensor had a long-term stable service lifetime suitable for remote monitoring in practical scene. Moreover, the sensor presented good thermo- and humidity-stability with good reproducibility and selectivity, making it an excellent monitor for H₂S in atmospheric environment on livestock-raising field.