Atomic layer deposition of Rh/ZnO nanostructures for anti-humidity detection of trimethylamine

The design of metal/semiconductor hybrid nanostructures is an important strategy for the development of efficient chemical gas sensors. In this paper, a highly sensitive gas-sensing material for trimethylamine (TMA) detection was designed by atomic layer deposition (ALD) of Rh onto ZnO flower-like nanostructures. The ZnO nanostructures consisted of porous nanosheets prepared by a hydrothermal method, and then functionalized with Rh catalysts to explore the sensing properties to TMA. The gas sensing investigations show that the loading of Rh has a remarkable influence on the performance of the sensors. The Rh/ZnO sensor with 10 cycles of Rh ALD showed the best response to TMA at 180 °C. A very high response of 11.3 was recorded when exposed to 10 ppm TMA, which is 3-times higher than that of pristine ZnO. Furthermore, the sensor also has a fast response-recovery and an excellent humidity resistance, as well as a low detection limit of 55 ppb, which suggest high potential for reliable detection of sub-ppm TMA. • ZnO flower-like nanostructures assembled by porous nanosheets were grown by hydrothermal method. • Rhodium (Rh) nanoparticles loaded on the surface of ZnO nanosheets were deposited by atomic layer deposition (ALD). • ALD of Rh leads to high detection sensitivity and good selectivity of TMA at low temperature. • ALD of Rh leads to high immunity to moisture of the sensor to detect TMA.