Novel β-CdSnO3-SnO2 nanorod-like heterostructure materials for enhancing n-butanol sensing

n -butanol detection is crucial to environmental protection and mankind’s health because of its toxicity and irritation to the respiratory system. Mono-metal oxide semiconductors (such as SnO 2 ) often face disadvantages such as low sensitivity, insufficient selectivity, and a high detection limit. Constructing heterojunctions has been considered an efficient way to enhance the performance of MOS gas sensors. This work presents the synthesis of a series of β -CdSnO 3 -SnO 2 nanorod-like heterostructures with good n -butanol sensitivity using a hydrothermal and post-calcination approach. The optimized CSO/SO-8 shows the highest response value about 90–100 ppm n -butanol at 190 °C, which is 15 times greater than that of SnO 2 , and 6.5 times more than that of β -CdSnO 3 . Meanwhile, the CSO/SO-8 also exhibits a short response and recovery time (1–2 s/63 s). More importantly, the detection limit is reduced to ppb level (50 ppb). The improved gas-sensitive properties can be explained by the formation of n - n heterojunctions between β -CdSnO 3 and SnO 2 , which increases the content of chemisorbed oxygen, thus enhancing the performance of the gas-sensitive. Our work not only provides a material with n - n heterostructures but also the strategy for constructing heterojunctions to improve gas-sensitive properties.