Characterization and gas sensing performances of noble metals decorated CuO nanorods

In this work, hydrogen and volatile organic compounds (VOCs) gas sensing properties of Pt/Pd decorated p-type CuO nanorods were investigated. CuO nanorods were hydrothermally grown on IDEs (interdigital electrodes) fabricated via photolithography and decorations of Pt/Pd on CuO nanorods were performed by RF magnetron sputtering with three decoration times (15 s, 30 s and 42 s). Morphological and structural characterizations were carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). Sensor characteristics of pristine and decorated nanorods were investigated for the detection of hydrogen and some VOCs. Sensing experiments show that optimum Pt and Pd decoration substantially enhanced ethanol and hydrogen sensitivity, respectively. Sensor response of optimum Pt decorated CuO nanorods to ethanol was about 60 fold higher than that of the pristine. Gas sensing mechanism highlighting the enhanced sensitivity to ethanol and hydrogen with Pt and Pd decoration is discussed in correlation with detailed XPS studies.