Highly sensitive and selective triethylamine sensor enabled by Ag/ZnO heterojunctions

Detecting triethylamine (TEA) is crucial due to its severe toxicity, posing risks to both the environment and human health. Currently, despite the urgency, developing TEA sensors with highly sensitivity and selectivity still remains challenging. Here, we report the exploration of highly sensitive and selective TEA sensors based on rationally-designed heterojunctions, which are constructed by Ag nanoparticles (Ag NPs) and mesoporous hierarchical ZnO nanosheets (ZnO NSs) through a simple wet impregnation process. The as-formed heterojunctions exhibit significantly enhanced selectivity and sensitivity for TEA sensing (S = 1000 at 10 ppm), which is more than 260 times higher than that of pristine ZnO NSs, and superior to most of ZnO-based sensors ever reported. Moreover, a small variation of TEA concentration (<0.5 ppm) can be detected with a fully reversible resistance signal, representing their promise toward practical applications.