Synthetic Principles of Spiky Au Nanoparticles

In this work, the synthetic principles of spiky Au nanoparticles (spiky Au NPs) with an average number of spikes of less than or equal to six and controlled core sizes by using Au nanorods as seeds (Au-NR seeds) are summarized on the basis of the results of a series of control experiments. In addition, one empirical equation that can roughly estimate the number of spiky Au NPs is proposed, demonstrated by the results of the products prepared from different aspect ratios of Au-NRs as seeds and non-Au-NR seeds. Moreover, the synthetic principles of spiky Au NPs are further demonstrated by taking the successful synthesis of a serials of spiky Au^21×7 NPs. Furthermore, the as-prepared spiky Au@Au_11.8Pd_88.2 NPs with ultrathin AuPd shells, which are derived from spiky Au^21×7 NPs with the smallest cores, can bear excellent catalytic activity (say, E_1/2 = 0.947 V) and durability toward the oxygen reduction reaction (ORR) in alkaline conditions, compared with commercial Pt/C catalysts (E_1/2 = 0.883 V).