Pd functionalization on ZnO nanowires for enhanced sensitivity and selectivity to hydrogen gas

초록

The detection of hydrogen (H₂) gas is of importance owing to its increasing use in the modern society to achieve a cleaner life environment. In this study, bare and palladium (Pd)-functionalized ZnO nanowires (NWs) were synthesized for H₂ gas sensing. The ZnO NWs were fabricated by a vapor-liquid-solid technique and Pd functionalization was performed using an ultraviolet irradiation technique. Enhanced H₂ gas response of the ZnO NWs was observed after Pd functionalization. Additionally, the Pd-functionalized ZnO NW gas sensor exhibited high selectivity to H₂ gas. The superior hydrogen gas sensing of the Pd-functionalized ZnO NW sensor was related mainly to the sensitization of the Pd nanoparticles, metallization effect of ZnO at the sensing temperature (350 °C), and partial PdHx formation. This study demonstrates the effectiveness of the Pd functionalization on the ZnO NWs for the realization of practical hydrogen gas sensors.

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