Substrate-free synthesis of WO3 nanorod arrays and their superb NH3-sensing performance.

Nanorod arrays possess a large surface area due to the orderly arrangement of monomers, and thus are considered as an ideal microstructure to be utilized in the interface-related process such as the gas-sensing reaction. But their adoption is plagued by the complicated synthesis route in which the substrate is usually necessary. Here we propose a substrate-free fabrication of WO 3 nanorod arrays through the facile hydrothermal method. Subsequent measurements testify the superior NH 3 -sensing property of WO 3 nanorod arrays. The corresponding response is as high as 8.3 at a concentration of 50 ppm and a temperature of 200 °C, surpassing other WO 3 -based NH 3 sensors reported. [ABSTRACT FROM AUTHOR]