Highly sensitive room temperature detection of trace trimethylamine by two dimensional ZnAlIn double hydroxide nanocomposites

Trimethylamine (TMA) gas is highly irritating and toxic, posing serious threats to human health and the environment. Traditional gas sensors typically rely on elevated temperatures (e.g., 200–400 °C) to activate surface reactions, resulting in high energy consumption and potential safety hazards. In this study, we successfully synthesized a nanocomposite sensing material based on two-dimensional ZnAl layered double hydroxides (LDHs) via a hydrothermal method and applied it for TMA detection at room temperature. To enhance gas sensing performance, In 3+ ions were introduced for surface modification and sensitization, resulting in ZnAlIn-LDHs materials with excellent TMA sensing characteristics. Structural and morphological characterizations confirmed the formation of In(OH) 3 /ZnAlIn-LDHs nanocomposites with optimized microstructures and enhanced surface activity. Gas sensing evaluations revealed that the sensor based on In(OH) 3 /ZnAlIn-LDHs exhibited a high response of 68.5 % ((R a -R g )/R a ∗100 %) to 100 ppm TMA, with a fast response time of 32 s and a recovery time of 34 s at room temperature. Additionally, the sensor demonstrated superior selectivity, long-term stability, and ppb-level detection capability, significantly outperforming pristine ZnAl-LDHs. The synergistic effect between In(OH) 3 and ZnAlIn-LDHs greatly improves the gas sensing performance, offering a promising strategy for the development of next-generation room-temperature TMA gas sensors with high sensitivity and low power consumption.