Enhanced NO 2 Sensing Performance of ZnO-SnO 2 Heterojunction Derived from Metal-Organic Frameworks.

Nitrogen dioxide (NO 2 ) is the major reason for acid rain and respiratory illness in humans. Therefore, rapid, portable, and effective detection of NO 2 is essential. Herein, a novel and simple method to construct a ZnO-SnO 2 heterojunction is fabricated by pyrolysis of bimetallic metal organic frameworks. The sensitivity of ZnO-SnO 2 heterojunction towards 0.2 ppm NO 2 under 180 °C is 37, which is 3 times that of pure ZnO and SnO 2 . The construction of heterojunction speeds up the response-recovery process, and this kind of material exhibits lower detection limit. The construction of heterojunction can significantly improve the NO 2 sensitivity. The selectivity, stability, and moisture resistance of ZnO-SnO 2 heterojunction are carried out. This could enable the realization of highly selective and sensitive portable detection of NO 2 .