Palladium/Bismuth/Copper Hierarchical Nano-Architectures for Efficient Hydrogen Evolution and Stable Hydrogen Detection.

Efficient, stable electrode catalysts and advanced hydrogen sensing materials are the core of the hydrogen production and hydrogen detection for guaranteeing the safe issues. Although a universal material to achieve the above missions is highly desirable, it remains challenging. Here, we report palladium/bismuth/copper hierarchical nanoarchitectures (Pd/Bi/Cu HNAs) for advanced dual-applications toward hydrogen evolution reaction (HER) and hydrogen detection, via first electrodeposition of cylindrical nanowires and subsequent wet-chemical etching art. For HER, the Pd/Bi/Cu HNAs present the overpotential (79 mV at 10 mA-2) and tafel slope (61 mV dec-1) closing to those of Pt/C. For hydrogen detection, the Pd/Bi/Cu HNAs was able to work at a wide-temperature range (∼156-418 K), and remarkably, their critical temperature (∼156 K) of the "reversing sensing behavior" is much lower than that of pure Pd nanowires (278 K). These excellent performances are ascribed to the synergic effect of hierarchical morphology induced more exposure of Pd, and the Pd d-band modification via Cu and Bi dopants. It is feasible that Pd/Bi/Cu HNAs serve as universal materials for both efficient catalysts toward hydrogen evolution via water electrolysis and wide-temperature adapted hydrogen detection.