Facet-engineered BiSI nanorods for intelligent distinguishing detection of NO₂/H₂S mixed gas

Room-temperature detection of harmful gases is essential for industrial intelligence, whereas the development of practical multigas sensors for real-world applications remains insufficient. Guided by density functional theory calculations, which reveal the superior adsorption and charge-transfer capability of the BiSI (121) facet toward both NO₂ and H₂S, a facet-engineered BiSI nanorod sensor was designed to achieve bifunctional sensing, exhibiting remarkable responses of 610% and −437% to 1 ppm NO₂ and H₂S at room temperature, respectively. Further integration of the single facet-controlled BiSI sensor with a back-propagation neural network allows for the intelligent analysis of mixed gases, achieving both distinguishing detection and concentration prediction. This systematic design effectively overcomes the limitations of high-power consumption and complex modulated operating conditions. This strategy provides a low-power and integrated generalizable framework for simultaneous multigas detection, applicable to a wide range of industrial and environmental monitoring scenarios. (Figure presented.).