AbstractThe ZnO−SnO2 nanocomposite has been synthesized using the simple and low‐cost co‐precipitation method. The physicochemical characterization of the prepared nanocomposites was carried out by using X‐ray diffraction (XRD), Field Emission Scanning Electron Microscope (FE‐SEM), High‐resolution Transmission Electron Microscopy (HR‐TEM), Energy Dispersive X‐ray analysis (EDAX) and UV‐visible spectroscopy techniques. In XRD confirmed that, hexagonal wurtzite phase of ZnO with the tetragonal rutile phase of SnO2 was found to be in the pure form. The particle size of the ZnO−SnO2 nanocomposite was fund to be ~23 nm in size. The nano cubes like surface morphology of the ZnO−SnO2 nanocomposite has been investigated using FESEM. Based on this various characterization, the ZnO−SnO2 nanocomposite has been used for the development of the chemiresistive gas sensor application. The gas sensitivity is found to be 29.30 % for 100 ppm NO2 gas at 200 °C operating temperature. This work has been used for the development of gas sensor devices for practical application.