Xingwei Wang, Likun Gong, Xiaohong Zhou
Abstract As a promising hydrogen carrier for low‐carbon energy cycling, ammonia also represents the most abundant alkaline gas in the atmosphere, impacting environmental quality through diverse geophysical and chemical processes. Hence, developing NH 3 sensing materials with high sensitivity and stability under self‐powered operation is essential. A one‐step in situ polymerization method is demonstrated to synthesize zinc oxide/graphene oxide (ZnO/GO) nanocomposites, serving as a gas‐sensitive film for ammonia sensing and as high‐performance electrode materials in supercapacitors, simultaneously. For the supercapacitor, the specific capacitance of 131 F g −1 at 1 A g −1 is achieved. The ammonia sensor featured a low detection limit (0.1 ppm) and fast response/recovery time (17 s/26 s @ 10 ppm NH 3 ), surpassing standards set by the US Occupational Safety and Health Administration (50 ppm), while outperforming commercial NH 3 gas sensors. By integrating the sensor into a detection instrument for fixed‐point monitoring, the response relative standard deviation of below 1% over 210 days of continuous testing is achieved. In addition, a wearable contact‐separated TENG is developed to harvest mechanical energy from a contact‐separation setup that mimicked human footsteps, achieving a maximum output power of 4.1 mW to directly drive the ammonia gas sensor. The multi‐scenario applications enhanced the spatial coverage and operational flexibility of NH 3 concentration monitoring.