Pyrolyzing Co/Zn bimetallic organic framework to form p-n heterojunction of Co3O4/ZnO for detection of formaldehyde

he Co3O4/ZnO composites with porous and high specific surface were prepared by calcination of Co and Zn-based bimetallic organic framework (MOFs). The influence of the calcination temperature on structure and morphology of composite has been discussed by means of the analysis of XRD, FESEM, HRTEM and XPS spectra. Gas-sensing experiment reveals that the response of composite (Co/ Zn = 4: 1 At.) is 5 times higher than that of pristine Co3O4 to 10 ppm HCHO at 120 degrees C and exhibits a rapid response, good selectivity, and stability. Such excellent performance is attributed to the large specific surface area and porous structure resulting from pyrolyzing of MOFs framework, which is beneficial to gas adsorption, diffusion and surface reaction. This MOF-driven strategy is expected to be a promising method for preparation of other metal oxide composites and application in detecting toxic gas.