A humidity-tolerant NO2 sensor based on Ag3PO4–SnSe2 heterostructures

Abstract

Gas sensing under harsh conditions, like humid environments, is highly required in the development of the Internet of Things. However, conventional gas sensors based on metal oxide semiconductors often suffer from a deterioration in sensing performance in a highly humid environment. Herein, Ag₃PO₄–SnSe₂ heterostructures were constructed as a NO₂ sensing material to work under highly humid environments at room temperature. The Ag₃PO₄–SnSe₂ sensor exhibited an increased response with the increase in relative humidity. The chemical inertness to H₂O molecules of SnSe₂ and the high affinity to H₂O molecules of Ag₃PO₄ played vital roles in improving the anti-humidity ability. Additionally, the sensor also demonstrated a high sensing response (6.8) to 5 ppm NO₂ and a short response/recovery time (31/108 s) at room temperature. This study provides a new method to design advanced gas sensors with a high anti-humidity ability for room temperature NO₂ detection.