Cobalt Nanoparticles Modified Single-Walled Titanium Carbonitride Nanotube Derived from Solid-Solid Separation for Oxygen Reduction Reaction in Alkaline Solution
Cobalt Nanoparticles Modified Single-Walled Titanium Carbonitride Nanotube Derived from Solid-Solid Separation for Oxygen Reduction Reaction in Alkaline Solution
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DOI：
10.1007/s12678-020-00614-x
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发表时间：
2020-07
期刊：
影响因子：
3.1
通讯作者：
Sefiu A. Rasaki;Zhangwei Chen;Hangjia Shen;Haichuan Guo;Tiju Thomas;Minghui Yang
中科院分区：
文献类型：
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作者：
Sefiu A. Rasaki;Zhangwei Chen;Hangjia Shen;Haichuan Guo;Tiju Thomas;Minghui Yang
碳氮化钛对于氧还原反应（ORR）具有良好的催化性能。然而，其合成通常需要高温（1200–1800°C），因此限制了对其进行的研究。迄今为止，碳氮化物的催化性能已通过合成后部分表面氧化得到了改善。这使得制备所需催化剂的整个过程变得繁琐和复杂。在这项工作中，通过溶剂热法和固-固分离过程合成了钴修饰的单壁碳氮化钛纳米管（Co@TiC0.25N0.75）。成功克服了TiCN合成所需的高温问题，并采用Co掺杂策略提高了其催化性能。 TiC0.25N0.75上负载不同质量比的Co纳米粒子。研究发现，由于溶解度极限约为 0.98%，只有一小部分 Co 溶解在 TiC0.25N0.75 晶格中。剩余部分的 Co 存在于 TiC0.25N0.75 的壁上。 TiC0.25N0.75wall 处的 Co 纳米粒子补充了催化活性，而其晶格中溶解的 Co 通过增加低价态 Ti 2p3/2 的比例充当活性位点改性剂。在碱性溶液中，10%Co@TiC0.25N0.75 显示出明显的 ORR 活性，起始电位和半波电位分别位于 0.85 和 0.73 V；性能高于TiN（0.69和0.55 V）和单相TiC0.25N0.75（0.74和0.62 V）。结果表明，由于强耦合效应，Co和TiC0.25N0.75之间发生了电荷转移。这使得催化剂具有显着的ORR活性和稳定性。图解摘要结构摘要通过固-固分离方法克服了碳氮化钛合成中的高温问题，并采用Co掺杂策略来提高其催化性能。在碱性溶液中进行 ORR 活动期间，Co@TiC0.25N0.75 给出 ~ 4.9 mA cm−2 的明显电流密度。起始电位和半波电位相对于 RHE 分别为 0.85 和 0.73 V。
Titanium carbonitrides have promising catalytic properties for oxygen reduction reaction (ORR). However, its synthesis normally requires high temperatures (1200–1800 °C), thus limiting research carried-out on them. The catalytic properties of the carbonitrides have so far been improved through post-synthesis partial surface oxidation. This makes the entire process of making the desired catalyst cumbersome and complex. In this work, cobalt-modified single-walled titanium carbonitride nanotube (Co@TiC0.25N0.75) is synthesized via solvothermal method followed by solid-solid separation process. The problem of high temperature required for TiCN synthesis is successfully overcome, and a Co doping strategy is used to improve its catalytic performance. Different mass ratios of Co nanoparticles are loaded onto TiC0.25N0.75. It discovers that only a fraction of the Co dissolves at TiC0.25N0.75lattice due to the solubility limit being ~ 0.98%. The remaining fraction of Co is found at the wall of the TiC0.25N0.75. The Co nanoparticles at the TiC0.25N0.75wall complement the catalytic activity, while the dissolved Co at its lattice acts as active site modifier by increasing the proportion of Ti 2p3/2in the low valence state. In alkaline solution, 10%Co@TiC0.25N0.75shows appreciable ORR activity with onset and half-wave potential located at 0.85 and 0.73 V respectively; the performance is higher than that of TiN (0.69 and 0.55 V) and single-phase TiC0.25N0.75(0.74 and 0.62 V). The results indicate that a charge transfer occurred between Co and TiC0.25N0.75due to strong coupling effect. This gives a catalyst with appreciable ORR activity and stability.Graphical AbstractTextural AbstractHigh temperature, a problem associated with titanium carbonitride synthesis, is overcome through solid-solid separation method, and Co doping strategy is used to improve its catalytic performance. During ORR activity in alkaline solution, Co@TiC0.25N0.75gives appreciable current density of ~ 4.9 mA cm−2. Onset and half-wave potential are found to be 0.85 and 0.73 V vs RHE respectively.