ZnO nanotetrapods have been synthesized by carbothermal method. The structure, phase, morphology of the synthesized sample were investigated by X-ray diffraction and X-ray photoelectron spectroscopy, Scanning electron microscopy, Transmission electron microscopy and Selected area electron diffraction. The gas-sensing characteristics of thick films of pure and CuO-functionalized ZnO Nanotetrapods have been compared. Pure ZnO nanotetrapod films were found to be sensitive to both H₂S and NO with similar sensitivities, at a temperature of 250-300 °C. It is demonstrated that functionalization of ZnO nanotetrapods with CuO, results in selectivity towards H₂S at a lower temperature of 50 °C.