Construction of hierarchical In2O3/In2S3 microsphere heterostructures for TEA detection

Construction of heterojunction has been considered as an efficient strategy to enhance the gas-sensing performances of metal oxide semiconductors. On this basis, hierarchical In2O3/In2S3 microsphere heterostructures were synthesized by partial oxidation of In2S3 precursors which were obtained via a facile hydrothermal method. Besides, gas sensors based on the acquired materials were fabricated to investigate their sensing performances toward triethylamine (TEA). The results reveal that the gas sensor based on In2O3/In2S3 exhibits a high response of 37 at 300 °C toward 0.45 mg/L TEA, which is 3.7 times higher than that of bare In2O3. Meanwhile, it also possesses fast response/recovery time (19 s/154 s), good repeatability, selectivity and long-term stability. The excellent sensing performances toward TEA are mainly attributed to the massive oxygen vacancy defects and heterojunction formed between In2O3 and In2S3. This work provides a facile temperature-dependent route to controllably synthesize hierarchical In2O3/In2S3 microsphere heterostructures, and the In2O3/In2S3 sensor shows great application prospects in TEA detection. [Display omitted] •Hierarchical In2O3/In2S3 microsphere heterostructures were constructed via incomplete oxidation of In2S3 precursors.•The composition and structure of In2O3/In2S3 can be tuned by controlling the calcination temperature of the In2S3 precursors.•The In2O3/In2S3 sensor exhibited high response, short response time and low detection limit towards triethylamine.•The triethylamine sensing mechanism of In2O3/In2S3 was discussed in detail.