In2S3/Ti3C2Tx/TiO2−x S-Scheme Heterojunction: Photo-Activated Enhanced Room-Temperature Ammonia Gas Sensors Inspired by Plant Photosynthesis

The necessity for high-efficiency, low-power room-temperature (RT) ammonia (NH3) sensors is particularly acute in environmental monitoring, industrial safety, and medical diagnostics. However, conventional chemiresistive sensors frequently require elevated temperatures to initiate reactions, leading to high energy consumption and potential safety risks. Inspired by plant photosynthesis, this paper successfully designs a ternary S-scheme heterojunction for a photo-activated RT NH3 sensor. The design effectively mimics the efficient charge transfer process in photosynthesis, thereby significantly promoting the separation and migration of photogenerated carriers and enhancing the sensing performance. Experimental results demonstrate exceptional performance under illumination: a high response value of 1679% (representing a 20-fold improvement over the dark state), rapid response and recovery times of 2.1 s and 1.9 s, respectively, along with outstanding selectivity, excellent stability, and a detection limit as low as 17 ppb. This work demonstrates a novel, efficient RT photo-activated NH3 sensor and provides innovative insights into designing biomimetic, smart gas-sensing materials and devices.