Thamer Badr M, Abdul Hameed Meera Moydeen, El-Newehy Mohamed H
Department of Chemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
Department of Chemistry, Faculty of Science, Tanta University, Tanta 31527, Egypt.
Gels. 2023 Mar 17;9(3):238. doi: 10.3390/gels9030238.
The preparation of metallic nanostructures supported on porous carbon materials that are facile, green, efficient, and low-cost is desirable to reduce the cost of electrocatalysts, as well as reduce environmental pollutants. In this study, a series of bimetallic nickel-iron sheets supported on porous carbon nanosheet (NiFe@PCNs) electrocatalysts were synthesized by molten salt synthesis without using any organic solvent or surfactant through controlled metal precursors. The as-prepared NiFe@PCNs were characterized by scanning and transmission electron microscopy (SEM and TEM), X-ray diffraction, and photoelectron spectroscopy (XRD and XPS). The TEM results indicated the growth of NiFe sheets on porous carbon nanosheets. The XRD analysis confirmed that the NiFe alloy had a face-centered polycrystalline (fcc) structure with particle sizes ranging from 15.5 to 30.6 nm. The electrochemical tests showed that the catalytic activity and stability were highly dependent on the iron content. The electrocatalytic activity of catalysts for methanol oxidation demonstrated a nonlinear relationship with the iron ratio. The catalyst doped with 10% iron showed a higher activity compared to the pure nickel catalyst. The maximum current density of NiFe@PCNs (Ni/Fe ratio 9:1) was 190 mA/cm at 1.0 M of methanol. In addition to the high electroactivity, the NiFe@PCNs showed great improvement in stability over 1000 s at 0.5 V with a retained activity of 97%. This method can be used to prepare various bimetallic sheets supported on porous carbon nanosheet electrocatalysts.
制备负载在多孔碳材料上的金属纳米结构，要求其简便、绿色、高效且低成本，以降低电催化剂成本，并减少环境污染物。在本研究中，通过熔盐合成法，在不使用任何有机溶剂或表面活性剂的情况下，通过控制金属前驱体，合成了一系列负载在多孔碳纳米片上的双金属镍铁薄片（NiFe@PCNs）电催化剂。通过扫描电子显微镜和透射电子显微镜（SEM和TEM）、X射线衍射和光电子能谱（XRD和XPS）对所制备的NiFe@PCNs进行了表征。TEM结果表明镍铁薄片生长在多孔碳纳米片上。XRD分析证实NiFe合金具有面心多晶（fcc）结构，粒径范围为15.5至30.6 nm。电化学测试表明，催化活性和稳定性高度依赖于铁含量。催化剂对甲醇氧化的电催化活性与铁比例呈非线性关系。与纯镍催化剂相比，掺杂10%铁的催化剂表现出更高的活性。在1.0 M甲醇浓度下，NiFe@PCNs（Ni/Fe比例为9:1）的最大电流密度为190 mA/cm²。除了高电活性外，NiFe@PCNs在0.5 V下1000 s内的稳定性有很大提高，活性保留率为97%。该方法可用于制备各种负载在多孔碳纳米片上的双金属薄片电催化剂。
