UV-Enhanced Room-Temperature Ammonia Detection Using a Ga₂O₃/Ti₃C₂Tₓ MXene Gas Sensor

The present study proposes a Ga2O3/Ti3C2Tx heterojunction-based gas sensor capable of detecting NH3 at room temperature. In this heterojunction, Ga2O3 nanorods, a type of metal oxide, were synthesized on 2-D Ti3C2Tx MXene using a hydrothermal method. The sensor was fabricated by drop casting the Ga2O3/Ti3C2Tx composite onto interdigitated electrodes (IDEs) and evaluated under varying NH3 concentrations with and without ultraviolet (UV) illumination. The fabricated Ga2O3/Ti3C2Tx heterojunction exhibits enhanced reactivity with ammonia gas due to the high surface area of Ga2O3 and the superior electrical conductivity of Ti3 C2Tx, resulting in a synergistic effect that significantly improves NH3 detection performance. In addition, when exposed to UV light at room temperature, the Ga2O3/Ti3C2Tx gas sensor demonstrates an increased response and stable baseline resistance recovery. The response to 25-ppm NH3 increased from 18.68% without UV to 23.47% with UV, highlighting the enhanced performance enabled by UV illumination. These findings indicate the sensor’s potential for ammonia detection across a wide concentration range and highlight its promise for commercial applications in various environmental settings.