Vanadium doping as a key factor for superior NH3 sensing at room temperature in MoSe2/TiO2 composites

Abstract

The detection of ammonia is critical in various industrial and environmental applications due to its toxicity and contribution to air pollution. Effective ammonia sensors are essential for monitoring emissions in agricultural, chemical, and manufacturing processes, as well as for ensuring workplace safety and regulatory compliance. The present work investigates the gas sensing performance of vanadium-doped titanium dioxide/molybdenum diselenide (VTOMS) composite against ammonia in comparison to different volatile organic compounds. Interestingly, VTOMS demonstrated significantly higher sensitivity and selectivity towards ammonia in comparison to other volatile organic compounds. A comprehensive analysis of key sensing parameters revealed that the composite material exhibits superior performance over the molybdenum diselenide and titanium dioxide, showing a remarkable response time of 94 seconds and a recovery time of 50 seconds. The sensitivity of the sensor is ∼ 3.05 per part per million with a noise standard deviation of ∼ 0.305. The limit of detection for the sensor is found to be approximately 0.3 parts per million(ppm), indicating that the sensor is capable of detecting very low concentrations of ammonia. The study demonstrates significant potential of the molybdenum diselenide/vanadium-doped titanium dioxide (VTOMS) composite as a high-performance ammonia sensor, offering improved sensitivity, selectivity, and rapid response characteristics, which make it an ideal candidate for practical applications where accurate ammonia detection is critical.