The nucleation of single hydrogen (H2) nanobubbles is explored in Ag nanoelectrodes (NEs, radius is 5–65 nm), where H2 is produced through proton electroreduction in H2SO4 solution. Moreover, Ag NEs covered by MoS2 quantum dots (denoted as Ag@MoS2 QD NEs) show a more positive bubble formation potential than pure Ag NEs. Furthermore, the kinetic parameters of rate-determining steps for the hydrogen evolution reaction (HER) were calculated at Ag NEs and Ag@MoS2 QD NEs by microkinetic analyses. The average value of the standard rate constant (k 0) of Ag@MoS2 QD NEs is ∼10-fold of that at Ag NEs, as well as the positive shift of nanobubble formation potential, indicating the higher HER activity of Ag@MoS2 QDs. Our work will provide a new insight to design and evaluate HER catalysts based on the nanobubble formation.

Silver nanowires (AgNWs) have been extensively studied as promising nanomaterials in optics, next‐generation flexible electronics, and energy‐related fields, but the stability and the properties at single‐nanowire level still need to be investigated carefully. We have successfully prepared single palladium@silver nanowire electrodes (Pd@AgNWEs) by using a laser‐assisted pulling method, followed by a galvanic replacement reaction (GRR). The results show that the chemical stability of AgNWs can be improved greatly by coating a small amount of Pd, and the Pd@AgNWEs exhibit superior electrocatalytic performance in methanol oxidation. This work can give us a new insight to investigate the performance of devices/catalysts at the single‐particle/nanowire level that will benefit research in flexible electronics and energy‐related fields.

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