Room-temperature high-performance ammonia gas sensing based on rGO nanosheets/MoO3 nanoribbons nanocomposites film

Sensitive detection of ultra-low concentration ammonia gas (NH3) at room temperature is crucial in the fields of respiratory disease diagnosis and gas monitoring. Recently, various metal oxide semiconductor-based sensors have been investigated to attain this goal. However, a trade-off between operating temperature and sensing performance is far from satisfactory. Incorporating metal oxides with highly conductive nanofillers is a feasible strategy for addressing this problem. In this work, reduced graphene oxide nanosheets/molybdenum trioxide nanoribbons (rGO/MoO3) nanocomposites were synthesized through a facile one-step hydrothermal method and employed as NH3 sensing materials. As opposed to solely MoO3 sensors, rGO/MoO3 one possessed enhanced performance at room temperature (20 +/- 2 degrees C), including boosted response (32.44% vs. 15.11% towards 5 ppm, which was the best case among MoO3-based NH3 sensors considering temperature and response), and faster response speed (33 s vs. 84 s towards 5 ppm). Besides, the practical detect limit of rGO/MoO3 sensor was as low as 200 ppb. Moreover, modest selectivity, humidity resistance and excellent stability were revealed. These improvements might benefit from the synergistic effect between rGO and MoO3, abundant sorption sites, porous film and high conductivity of rGO nanosheets. These results indicated rGO/MoO3 nanomaterials had great potential in rapid real-time monitoring of ultralow NH3 emissions at room temperature.

Automated summary

This study investigates the use of rGO/MoO3 nanocomposites as sensing materials for the sensitive detection of ultra-low concentration NH3 gas at room temperature. The results show that the rGO/MoO3 sensor outperforms the MoO3 sensor in terms of response rate and response speed, with a lower detection limit and good selectivity, humidity resistance, and stability.