Heterostructure construction and oxygen vacancy regulation can improve the electrical properties of metal-oxide semiconductors (MOSs), leading to an improved gas-sensing performance. Therefore, a series of BiOBr/MoO3 heterojunction composites were synthesized via a two-step fabrication strategy combining hydrothermal and chemical precipitation routes. It was found that BiOBr/MoO3 exhibits excellent gas-sensing properties for triethylamine (TEA), compared with pure MoO3 and BiOBr. The sample BBM-3, synthesized with a BiOBr/MoO3 molar ratio of 0.15, exhibits a high response (Ra/Rg = 311) toward 50 ppm of TEA at an operating temperature of 175 °C, as well as excellent selectivity and stability. A detailed discussion regarding the enhanced gas-sensing mechanism is provided due to the enhanced carrier transport properties caused by heterojunctions and oxygen vacancies. This study sheds new light on regulating the carrier transport properties of MOS-based materials, which is beneficial for the development of new gas-sensitive materials.
陆国彪 et al. (Thu,) studied this question.