Metal oxide (MOX) semiconducting materials, such as ZnO, SnO₂, In₂O₃ and WO₃, are the main active materials for chemresistor gas sensor due to their low cost, portability, real-time operability and ease of use. MOX based gas sensor has been developed for many industrial and domestic applications on detecting volatile organic compounds (VOCs). However, several ways such as cross-sensitivity adjustment, electronic noses and gas pre-separation by other instrument have been developed to optimize its performances, but MOX gas sensor still need to overcome the poor selectivity and high working temperature for broader commercial applications.

Metal organic frameworks (MOFs) feature regular pores, ultra-large surface areas, tuneable framework structures and open-metal sites. These features make MOFs an ideal candidate to overcome the above mentioned long-term bottlenecks of chemiresistor gas sensor . Here, we demonstrate this possiblity by two strategies of material design to optimize the performances of gas sensor:1) high quality semi-conductive MOF thin film was prepared to act as sensing active layer directly; 2) MOX@MOF core-sheath structured nanowire array was design and prepared to act the sensing active layer. The chemiresistor gas sensors based on above materials have not only exhibited improved sensitivity, but also reduced the working temperature.[1,2] Given that MOF material has greatly variable and designable structure and properties, new material designed with MOFs is promising to simplify the structure and decrease the cost of gas sensor for its application on wearable devices, intelligent automobile, smart electrical home appliances and other precise detection fields in future.

Refences:

1. Ming-Shui Yao, Xiao-Jing Lv, Zhi-Hua Fu, Wen-Hua Li, Wei-Hua Deng, Guo-Dong Wu, and Gang Xu* Angew. Chem. Int. Ed. 2017, 56, 16510.

2. Ming-Shui Yao, Wen-Xiang Tang, Guan-E Wang, Bhaskar Nath, and Gang Xu* Adv. Mater. 2016, 28, 5229.