Enhanced ammonia sensing performance of Au nanoparticle-functionalized ZnSnO3 cubes at low temperature

摘要

The low-temperature detection of ammonia gas (NH3) is essential in daily life and environment protection. In this work, Au nanoparticle-functionalized ZnSnO3 cubes have been synthesized by a simple solution-based chemical method. Surface morphology characterization and chemical state analysis were combined to indicate that the Au nanoparticles (NPs) were well contacted with ZnSnO3 cubes to form the Schottky barrier-type junctions from characterization results. Based on the chemical catalysis and the Schottky barrier, the sensor based on Au-ZnSnO3 cubes demonstrated excellent response (94.3 to 100 ppm) and better selectivity to ammonia gas at low temperature (80 degrees C) with the fast response/recovery time of 8/5 s. Meanwhile, the sensor exhibited good repeatability stability and high selectivity towards ammonia among other test gases. The sensing mechanism was proposed in terms of the combination of ZnSnO3 cube structure and catalytic activity of Au nanoparticles loaded. This work provides an efficient strategy for the fabrication of NH3 sensors at low temperature.