GaN/rGO nanocomposite gas sensor for enhanced NH3 sensing performances at room temperature

In this work, we developed a high-performance NH3 sensor based on GaN/rGO nanocomposites via a low-cost solvothermal method and subsequent nitridation process. The morphological, structural, and chemical compositions were investigated to demonstrate that GaN and rGO were coupled together by interfacial modulation, and the GaN/rGO heterostructure chemical bonds are successfully formed. Gas-sensing performance test results show that the fabricated GaN/rGO (2.2 wt%) NH3 sensor exhibited a high response value (92%), fast response time (11 s), and low limit of detection (500 ppb) at room temperature. In addition, reproducibility, humidity, and long-term stability tests of the GaN/rGO sensor were also conducted in this work. The enhancement sensing mechanisms are attributed to the large specific surface area, the excellent conductivity of rGO, and resistance modulation effect of the heterojunction potential. Hence, the GaN/rGO gas sensor can be regarded as a promising sensing solution for atmospheric and exhaled NH3 detection at room temperature.