NiO/BiVO4 p-n heterojunction microspheres for conductometric triethylamine gas sensors

Triethylamine (TEA), a clear and colorless liquid with strong ammonia odor, has great danger to human health and environment. We synthesize the NiO/BiVO4 p-n heterojunction microspheres using hydrothermal method for TEA detection. To characterize the as-prepared samples, XRD, XPS, SEM, UV–vis, and EIS are used. Among the pure NiO, BiVO4, 5%NiO-BiVO4 and 30%NiO-BiVO4, the 10%NiO-BiVO4 sensor exhibits excellent gas sensing properties, including fast response/recovery times, high humidity resistance, and low detection limit of 3.42 ppb toward TEA. Moreover, the enhanced mechanism of NiO/BiVO4 p-n heterojunction microsphere is also proposed. Consequently, NiO coupled with BiVO4 to form NiO-BiVO4 can be an effective strategy for improving TEA gas sensors.