Rapid room-temperature NO2 detection based on Bi2S3/polyoxometalate heterostructures: the synergy of increased electron transportation and heterojunction effect

Abstract

With the significant increase in global awareness of environmental protection, green non-toxic gas sensors have become an important tool to promote sustainable development. In this work, a gas sensor based on Bi₂S₃ green non-toxic semiconductor material was successfully prepared. By introducing polyoxometalate (POMs) electron acceptor into Bi₂S₃ sensing material, its detection ability for NO₂ gas was significantly improved. At room temperature (25°C), the Bi₂S₃/1%PW₁₂ sensor has a response value of 41.88 to 100 ppm NO₂, which is 4.36 times the response value of the Bi₂S₃ sensor (9.61), highlighting its excellent detection performance. In addition, we thoroughly evaluated the selectivity, repeatability and other key gas sensing parameters of the sensor, further confirming its high-potential in practical applications. Through analysis of the mechanism underlying the performance enhancement, it is found that the appropriate addition of PW₁₂ as an electron acceptor can effectively inhibit the electron-hole recombination, thus significantly improving the performance of the sensor. This important discovery opens up a new way and method for the performance optimization of gas sensors, and is expected to inject new vitality into the future development of gas sensor technology.