Excellent long-term stable H2S gas sensor based on Nb2O5/SnO2 core-shell heterostructure nanorods

• ALD of controllable SnO 2 shell thickness on Nb 2 O 5 nanorods for H 2 S sensing. • The H 2 S sensing performance is closely related to the thickness of SnO 2 shell. • The H 2 S sensors exhibit high response, good selectivity, and excellent stability. Heterostructured Nb 2 O 5 /SnO 2 core-shell nanorods are synthesized by a facile hydrothermal strategy and atomic layer deposition (ALD). The SnO 2 shell thicknesses varying from 7 to 34 nm exhibit a significant impact on sensing performance. The response enhancement mechanism of the Nb 2 O 5 /SnO 2 core-shell nanorods is illustrated based on the electron-depletion model. The Nb 2 O 5 /SnO 2 core-shell nanorods gas sensors were synthesized based on the micro-electromechanical systems (MEMS), which could provide variable operating temperatures for the gas sensors with highly integrated design and low power consumption. The response of the Nb 2 O 5 /SnO 2 core-shell nanorods gas sensor deposited with 20 nm SnO 2 shell towards 20 ppm H 2 S at 275 °C was 4.0, which showed a 3.8-fold of improvement compared with pristine Nb 2 O 5 nanorods. Furthermore, the well-structured core-shell nanorods gas sensors maintained stable performance after three months, presenting long-term stability and repeatability. The proposed Nb 2 O 5 /SnO 2 core-shell nanorods gas sensors demonstrate a potential strategy for the practical application in oil and gas drilling platforms and other industrial fields.