Construction of ZnO-SnO2 n-n junction for dual-sensing of nitrogen dioxide and ethanol

As inspired by the recent reports that many unique properties can be achieved by using two dissimilar components to form hetemstmctures, especially for materials in nano-size. In this letter, one-dimensional ZnO-SnO2 heterostructures were constructed by uniformly growing SnO2 nanoparticles on the surfaces of ZnO nanowires. Compared with pure ZnO nanowires, ZnO-SnO2 heterostructures exhibited significant enhancement in response and selectivity to NO2 and ethanol. The excellent response/recovery characteristics and stability of ZnO-SnO2 heterostructures demonstrate that the hetemstmcture construction is promising for dual sensing of NO2 and ethanol using one sensor. The possible enhancement sensing mechanisms were discussed based on the depletion control and potential barrier control models.