State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, People's Republic of China. University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
Nanotechnology. 2019 Feb 15;30(7):075402. doi: 10.1088/1361-6528/aaf457. Epub 2018 Nov 27.
The design of high-efficient and durable bi-functional oxygen electrocatalysts is still a great challenge. In this work, novel CoS nanoparticles/N,S-codoped defect-rich carbon nanotubes (CoS/N,S-CNTs) were fabricated by an ingenious template method. CdS nanowires, as a sacrificial template, can be removed simultaneously during the carbonization process without additional post-treatments. The large BET surface area (661.2 m g) and pore volume (1.49 cm g) of CoS/N,S-CNTs could largely enhance the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activities by facilitating the mass transportation and exposing more active sites. The abundant defects produced by the evaporation of Cd and S doping could provide more active sites for ORR and OER. Coupling with CoS, CoS/N,S-CNTs possesses more defects in the carbon skeleton, better electron conductivity, and larger effective electrochemical area. CoS/N,S-CNTs not only performs excellent ORR activity with a half-wave potential of 0.821 V but also owns RuO-like OER activity in alkaline solution. The potential difference (ΔE) between ORR and OER is as low as 0.78 V in 0.10 M KOH. The excellent bi-functional performance enables the potential to be utilized in fuel cells and metal-air batteries.
设计高效且耐用的双功能氧电催化剂仍然是一个巨大的挑战。在这项工作中，通过巧妙的模板法制备了新型 CoS 纳米粒子/N，S 共掺杂富缺陷碳纳米管（CoS/N，S-CNTs）。CdS 纳米线作为牺牲模板，在碳化过程中可以同时去除，无需额外的后处理。CoS/N，S-CNTs 的大 BET 表面积（661.2 m g）和孔体积（1.49 cm g）可通过促进质量传输和暴露更多的活性位点，极大地提高氧还原反应（ORR）和氧析出反应（OER）活性。Cd 的蒸发和 S 掺杂产生的丰富缺陷可为 ORR 和 OER 提供更多的活性位点。与 CoS 结合，CoS/N，S-CNTs 在碳骨架中具有更多的缺陷、更好的电子导电性和更大的有效电化学面积。CoS/N，S-CNTs 不仅在碱性溶液中具有优异的 ORR 活性，半波电位为 0.821 V，而且具有类似 RuO 的 OER 活性。在 0.10 M KOH 中，ORR 和 OER 之间的电位差（ΔE）低至 0.78 V。优异的双功能性能使其有望应用于燃料电池和金属空气电池。
