Surface Engineering on Palladium and Zinc Nanowires for Hydrogen Sensing Working at ≈190–388 K Temperature Range

Abstract

Reliable detection of hydrogen (H₂) leakage at low temperatures (e.g., < 273 K) is highly desired in those critical environments that may cause failure in detection, which needs further development. Herein, H₂ sensing that can work at ≈190–388 K temperature range has been developed by integrating palladium and zinc nanowires enwrapped with nanosheets (PdZn NWs) as the sensing materials, which have been prepared via combined anodic aluminum oxide (AAO) template-confined electrodeposition and surface engineering. Typically, as-synthesized PdZn NWs with a diameter of ≈50 nm present rough surfaces, along which abundant pores and fractures have been observed. Beneficially, the PdZn NWs show a lower critical temperature (≈190 K) of the “reverse sensing behavior” than that of pure Pd NWs (287 K), indicating the PdZn NWs are able to work at ≈190–388 K temperature range. Theoretically, such stable H₂ sensing can be attributed to the rough surfaces and chemical composition of PdZn NWs, which facilitates H atoms diffusion and accommodates the expansion of PdHx intermediates. The surface engineering of PdZn NWs may contribute to stable H₂ sensing at low temperatures, which can be applied to other gas-sensing materials working at low temperatures.