Zinc Oxide Gas Sensor Enhanced with Nano Beta Zeolite Catalyst for High-Sensitive Freon Detection

For the first time, nano beta zeolite (n-BEA) is used as catalyst to enhance the sensing performance of ZnO-based gas sensor for sub-ppm level Freon R22 detection. As a frequently used refrigerant, Freon R22 is hazardous to environment and needs to be detected. However, the conventional metal oxide sensor cannot be used to detect the inert Freon R22 molecules. Herein, n-BEA with great catalytic performance to Freon R22 is directly coated onto the surface of ZnO sensing material to form a novel dual- layer sensing material. The inert Freon R22 is firstly transformed into some active molecules in the n-BEA top- layer. Thereafter, the generated molecules can be sensed by the bottom ZnO material.