The sensitivity of chitosan/TiO2 film on ammonia detection

Abstract

Ammonia (NH3) is a toxic gas from various sources, including industrial waste, agriculture, and other human activities. The high concentration can cause negative impacts on air, water, and soil quality and harm human health and ecosystems. The objective of this research was to detect ammonia concentration based on chitosan-CS/titanium dioxide-TiO2 film. The CS solution was supplemented with TiO2 in quantities ranging from 0.01 g to 0.05 g, with increments of 0.01 g. The formed films were characterized using FTIR and SEM, the sensing characteristic of the CS/TiO2 film-based sensor was tested with ammonia by varying concentrations of (1.5, 3, 4.5, 6, and 7.5) mg/L. The FTIR and SEM analytical results indicated that the loading process of TiO2 proceeded only through physical interaction. The test results demonstrate that the CS-TiO2 film-based sensor has a higher maximum output voltage (0.223 V) than the CS film-based sensor (0.078 V) when exposed to 7.5 mg/L of ammonia. From the testing results, it was found that the CS/TiO2 film-based sensor with adding 0.02 g of TiO2 have good sensitivity, selectivity, reproducibility, fast response, compared to CS film-based sensors. However, it was inversely proportional by lifetime test. Finally, it can be concluded that Cs/TiO2 film-based sensor can be used for ammonia concentration detection.