Rapid room-temperature H2S detection based on Bi2S3/CuO heterostructures: the synergy of increased surface-adsorbed oxygen and heterojunction effect

Transition metal dichalcogenides (TMDCs)/metal oxide are increasing recognized as competitive sensing materials to detect at room temperature (RT). However, the unsatisfactory properties causing by low sensitivity, slow response, and weak discriminating ability towards interfering gases preclude their further applications in advanced sensing platforms. Herein, a Bi2S3/CuO heterostructure was demonstrated for H2S detection with highly sensitive and rapidly responding at RT. The Bi2S3/CuO sensor exhibited a greatly improved response (31.2 to 1 ppm H2S) with impressive response kinetics (7.5 s), surpassing that of pure Bi2S3 by a factor of 5 and 17, respectively. Besides, the sensor exhibits outstanding selectivity, repeatability, low detection limit (25 ppb), humidity tolerance and long-term stability. The distinctive enhancement of sensing capabilities primarily results from the synergistic influence of the heterostructure configuration and increased surface-adsorbed oxygen. The strategy of constructing heterostructures between a metal oxide and TMDC offers fundamental insights to develop room-temperature sensors.