Interfacial energy barrier tuning of hierarchical Bi2O3/WO3 heterojunctions for advanced triethylamine sensor

Abstract Traditional triethylamine (TEA) sensors suffer from the drawback of serious cross-sensitivity due to the low charge-transfer ability of gas-sensing materials. Herein, an advanced anti-interference TEA sensor is designed by utilizing interfacial energy barriers of hierarchical Bi 2 O 3 /WO 3 composite. Benefiting from abundant slit-like pores, desirable defect features, and amplification effect of heterojunctions, the sensor based on Bi 2 O 3 /WO 3 composite with 40% Bi 2 O 3 (0.4-Bi 2 O 3 /WO 3 ) demonstrates remarkable performance in terms of faster response/recovery time (1.7-fold/1.2-fold), higher response (2.1-fold), and lower power consumption (30 °C-decrement) as compared with the pristine WO 3 sensor. Furthermore, the composite sensor exhibits long-term stability, reproducibility, and negligible response towards interfering molecules, indicating the promising potential of Bi 2 O 3 /WO 3 heterojunctions in anti-interference detection of low-concentration TEA in real applications. This work not only offers a rational solution to design advanced gas sensors by tuning the interfacial energy barriers of heterojunctions, but also provides a fundamental understanding of hierarchical Bi 2 O 3 structures in the gas-sensing field.