Boateng Emmanuel, McGuire Cameron, Xu Ruzhen, Jiang De-Tong, Chen Aicheng
Electrochemical Technology Center, Department of Chemistry, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada.
Department of Physics, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada.
ACS Appl Mater Interfaces. 2024 Sep 11;16(36):47703-47712. doi: 10.1021/acsami.4c10351. Epub 2024 Aug 27.
Heteroatom doping has been widely recognized as a key strategy for improving the electrochemical properties of graphene-based materials for hydrogen storage. However, a precise understanding of how heteroatom doping influences catalytic performance, specifically regarding the intricate effects of doping-induced electron redistribution, has been lacking. Here, we report on a comprehensive exploration of the electrochemical performance enhancement in Pd-decorated reduced graphene oxide (rGO) nanocomposites through fluorine (F) or nitrogen (N) doping. Various analytical techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) spectroscopy, Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge structure (XANES), and extended X-ray absorption fine structure (EXAFS) were employed to thoroughly characterize the synthesized nanocomposites. The findings revealed that either F or N doping effectively addressed clustering issues of Pd nanoparticles formed on the rGO surface, resulting in improved homogeneity of Pd distribution. Electrochemical studies provided crucial insights into hydrogen adsorption-desorption behaviors. The heteroatom doped nanocomposites, Pd/N-rGO and Pd/F-rGO, exhibited superior electrochemical performance, which can be attributed to the increase of the active sites due to the N-/F-doping, respectively. The hydrogen discharge capacities of Pd/N-rGO (80.9 mAh g) and Pd/F-rGO (25.0 mAh g) nanocomposites were determined to be over 4.0 and 1.2 times higher than that of the Pd/rGO (20.1 mAh g), respectively. The distinctive electrochemical performances observed between the two types of heteroatom-containing nanocomposites highlight the subtle structural modifications of Pd nanoparticles as the key factor influencing performance. This research contributes essential knowledge to the evolving field of hydrogen storage materials, emphasizing the promising potential of heteroatom-doped Pd-decorated rGO nanocomposites for advancing clean and sustainable energy solutions.
杂原子掺杂已被广泛认为是改善用于储氢的石墨烯基材料电化学性能的关键策略。然而，目前仍缺乏对杂原子掺杂如何影响催化性能的精确理解，特别是关于掺杂诱导的电子重新分布的复杂影响。在此，我们报告了通过氟（F）或氮（N）掺杂对钯修饰的还原氧化石墨烯（rGO）纳米复合材料电化学性能增强的全面探索。采用了各种分析技术，如扫描电子显微镜（SEM）、透射电子显微镜（TEM）、能量色散X射线（EDX）光谱、拉曼光谱、X射线衍射（XRD）、X射线光电子能谱（XPS）、X射线吸收近边结构（XANES）和扩展X射线吸收精细结构（EXAFS），对合成的纳米复合材料进行了全面表征。研究结果表明，F或N掺杂有效地解决了在rGO表面形成的钯纳米颗粒的团聚问题，从而改善了钯分布的均匀性。电化学研究为氢吸附 - 解吸行为提供了关键见解。杂原子掺杂的纳米复合材料Pd/N - rGO和Pd/F - rGO表现出优异的电化学性能，这分别归因于N - /F - 掺杂导致的活性位点增加。Pd/N - rGO（80.9 mAh g）和Pd/F - rGO（25.0 mAh g）纳米复合材料的氢放电容量分别被确定为比Pd/rGO（20.1 mAh g）高出4.0倍和1.2倍以上。两种含杂原子的纳米复合材料之间观察到的独特电化学性能突出了钯纳米颗粒的细微结构修饰是影响性能的关键因素。这项研究为不断发展的储氢材料领域贡献了重要知识，强调了杂原子掺杂的钯修饰rGO纳米复合材料在推进清洁和可持续能源解决方案方面的广阔潜力。
