Diamond@carbon-onion hybrid nanostructure as a highly promising electrocatalyst for the oxygen reduction reaction

Abstract

The sp3-hybridized diamond structure was deliberately preserved at the core to retain stability, while modifying the sp2-hybridized surface carbon layers to enhance the ORR activity.

Heterogeneous NiO2-to-Pd Epitaxial Structure Performs Outstanding Oxygen Reduction Reaction Activity

“…These structures identified ligand effects and strain as levers to tune the surface electronic structure and the adsorption behavior of oxygenated intermediates during ORR. Along with Pt-based NCs, efforts for the development of Pt-free catalysts via various binary and ternary combinations of Pd, Au, Ag, with 3d transition metal, − carbon complexes, , metal oxides, − and nitrides are also underway. These studies provide opportunities to tune the electronic and chemical properties of metallic surface and laid the indispensable foundation for further research of Pt-free electrocatalysts.…”

Recent Progress in Diamond-based Electrocatalysts for Fuel Cells

“…Liu 等 [52] 利用光刻及等离子腐蚀技术, 首先制 [53] 采取滴落涂布法 将酞菁铜微晶修饰到氢终止和氧终止的 BDD 薄膜 表面,通过电化学测试分析发现酞菁铜微晶修饰氢 终止 BDD 对 ORR 的催化活性优于氧终止 BDD, 不 过催化的 ORR 主要是以 2 电子形式进行。 Koh 等 [54] 以 5 nm 的 ND 为基础材料, 利用真空热处理技术使 其表面碳化 , 形成石墨烯层 , 然后 , 使用改进的 Hummer 法腐蚀石墨烯层使其破裂, 并与三聚氰胺 混 合 热 处 理 , 对 破 裂 的 石 墨 烯 层 实 现 掺 氮 (N-exhND)。N-exhND 比 Pt/C 催化 ORR 的半坡电 位仅差 51 mV, 同时 N-exhND 具有明显的抗甲醇能 力。通过 5000 圈 ADT 以后, N-exhND 催化 ORR 的 半坡电位只左移 31 mV, 而 Pt/C 却左移 133 mV, N-exhND 的稳定性优势明显。 Dong 等 [55] 利用浓 H 2 SO 4 和浓 HNO 3 对石墨化 ND 表面的石墨烯层进行腐蚀处理, 使石墨结构中 出现更多缺陷, 然后引入三聚氰胺进行热处理, 最 终得到氮掺杂的石墨化 ND(N-C/ND)。ADT 结果证 明 N-C/ND 的高稳定性十分优异, ND 为核芯应该是 保证催化剂稳定性的关键因素。在 ND 的石墨化过 程中可以尝试掺杂 N、B，只是 ND 的石墨化温度 较高(高于 1200℃), B-C、C-N 键在高温环境下不稳 定(1000℃)。Liu 等 [56] 采用 FeCl 3 为催化剂, 降低了 ND 的石墨化温度, 并在其石墨化过程引入 B、 N 源, 实现 B、N 共掺杂, 即一步法对石墨化 ND 完成了 掺杂。 B、 N 双掺杂石墨化 ND 在碱性环境中对 ORR 催化活性较高, 且稳定性出色。Wu 等 [57] 则制备了…”

Promotional Effects of Nanodiamond‐Derived Onion‐Like Carbons on the Electrocatalytic Properties of Pd‐MnO2 for the Oxidation of Glycerol in Alkaline Medium

“…These advantages suggest extensive potential applications in nanoscale engineering and technologies. Indeed, OLC has been reported for several potential applications such as in supercapacitors,„ lithium‐ion battery, environmental remediation, ORR and catalysis …”