Highly Selective, Room‐Temperature Triethylamine Sensor Using Humidity‐Resistant Novel TiZn Alloy Nanoparticles‐Decorated MoS₂ Nanosheets
Hajeesh Kumar Vikraman, Jeena George, Rahul Suresh Ghuge, Rence P. Reji, Surya Velappa Jayaraman, Yoshiyuki Kawazoe, Yuvaraj Sivalingam, Mangalampalli S. R. N. Kiran
Abstract
The future of environmental monitoring, medical diagnostics, and industrial safety depends on developing room-temperature, long-term operable, stable, miniaturized, ultrahigh-performance sensors integrated into the Internet of Things (IoT). While noble metals and high-entropy alloys (HEAs) lead in addressing the limitations of conventional transition-metal dichalcogenides (TMDs) like MoS₂, they face challenges such as high-cost, limited availability, and fabrication complexity. To address this, multifunctional, cost-effective, humidity-insensitive novel phase Ti₀.₅Zn₀.₅ (TiZn) alloy nanoparticle-decorated MoS₂ nanosheets (MoS₂_NP) is developed for ultra-selective and highly sensitive triethylamine (TEA) vapor detection at room temperature (RT). This exhibited a 24-fold increase in response compared to MoS₂, with a high signal-to-noise ratio, negligible humidity interference, sensitivity of 9.92 × 10⁻⁵ ppm⁻¹ at RT, and a detection limit of 48 ppm. The enhanced catalytic activity and defect concentration, the reduction of the edge oxidation resulting in strong Fermi-level pinning, and the relatively high adsorption energy lead to a target gas-specific carrier-type response, demonstrating the potential of binary alloy nanoparticles (NPs) as decorative materials for enhanced sensing applications. The superior performance of the sensor led to the development of a TEA detection prototype interfaced with a mobile device via IoT for continuous monitoring, enhancing practicality and usability by offering immediate access to critical information.