Saleem Hamza, Park Hyunwoong, Park Yiseul
Department of Chemical Engineering, Pukyong National University, Busan 48513, Republic of Korea.
School of Energy Engineering, Kyungpook National University, Daegu 41566, Republic of Korea.
ACS Appl Mater Interfaces. 2025 Jul 9;17(27):39022-39031. doi: 10.1021/acsami.5c05060. Epub 2025 Jun 26.
In this study, we report a strategy to enhance the HER performance by exploiting the effective utilization of repurposed silver (Ag) to form bimetallic Pt-Ag alloy nanoparticles on silicon nanowires (SiNWs). Vertically aligned SiNWs were synthesized via metal-assisted chemical etching (MACE) on p-type silicon wafers during which Ag nanoparticles were intentionally retained at the nanowire base (rAg-SiNWs) to serve as nucleation sites for subsequent Pt photodeposition. Comprehensive characterizations using SEM, EDS, XRD, XPS, TEM, HRTEM, and HAADF-STEM confirmed the successful deposition of both Ag and Pt, as well as the formation of a uniform Pt-Ag alloy, as evidenced by distinct binding energy shifts in the deconvoluted Pt 4f spectra. Electrochemical measurements reveal that the Pt-decorated repurposed Ag-SiNWs (Pt-rAg-SiNWs) exhibit significantly enhanced HER performance compared with Pt-decorated SiNWs without repurposed Ag (Pt-SiNWs). Notably, the Pt-rAg-SiNWs contain a significantly lower Pt loading (0.18%) compared with Pt-SiNWs (0.75%). Despite this, they exhibit markedly higher current densities, lower overpotentials, and reduced Tafel slopes, highlighting the performance benefits associated with Pt-Ag alloy formation. The improved performance is attributed to the synergistic interaction between Pt and Ag, which enhances electron transfer, increases the electrochemically active surface area, and stabilizes the Pt active sites. These results provide valuable insights into the critical role of Ag positioning in facilitating effective Pt utilization via alloy formation and offer a cost-effective pathway for the design of advanced electrocatalysts for renewable energy applications.
在本研究中，我们报告了一种策略，即通过有效利用重新利用的银（Ag）在硅纳米线（SiNWs）上形成双金属Pt-Ag合金纳米颗粒来提高HER性能。通过金属辅助化学蚀刻（MACE）在p型硅片上合成垂直排列的SiNWs，在此过程中，Ag纳米颗粒被有意保留在纳米线基部（rAg-SiNWs），作为后续Pt光沉积的成核位点。使用SEM、EDS、XRD、XPS、TEM、HRTEM和HAADF-STEM进行的综合表征证实了Ag和Pt的成功沉积以及均匀Pt-Ag合金的形成，这在去卷积的Pt 4f光谱中明显的结合能位移得到了证明。电化学测量表明，与没有重新利用Ag的Pt修饰的SiNWs（Pt-SiNWs）相比，Pt修饰的重新利用的Ag-SiNWs（Pt-rAg-SiNWs）表现出显著增强的HER性能。值得注意的是，与Pt-SiNWs（0.75%）相比，Pt-rAg-SiNWs的Pt负载量显著更低（0.18%）。尽管如此，它们表现出明显更高的电流密度、更低的过电位和更小的塔菲尔斜率，突出了与Pt-Ag合金形成相关的性能优势。性能的提高归因于Pt和Ag之间的协同相互作用，这增强了电子转移，增加了电化学活性表面积，并稳定了Pt活性位点。这些结果为Ag定位在通过合金形成促进有效Pt利用中的关键作用提供了有价值的见解，并为设计用于可再生能源应用的先进电催化剂提供了一条具有成本效益的途径。
