In situ Cobalt-Cobalt Oxide/N-Doped Carbon Hybrids As Superior Bifunctional Electrocatalysts for Hydrogen and Oxygen Evolution
In situ Cobalt-Cobalt Oxide/N-Doped Carbon Hybrids As Superior Bifunctional Electrocatalysts for Hydrogen and Oxygen Evolution
复制标题
原位钴-氧化钴/氮掺杂碳杂化物作为优异的析氢和析氧双功能电催化剂
DOI：
10.1021/ja5127165
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发表时间：
2015-02-25
影响因子：
15
通讯作者：
Wang, Yong
中科院分区：
文献类型：
--
作者：
Jin, Haiyan;Wang, Jing;Wang, Yong
显着的析氢反应（HER）或上级析氧反应（OER）催化剂已被应用于水裂解中，然而，利用双功能催化剂同时产生H-2和O-2仍然是一个具有挑战性的问题，这对于提高水电解的整体效率至关重要。本文受碳导电性的优越性、金属钴良好的H原子结合能和氧化钴较好的OER活性的启发，采用简单的一锅热处理法合成了由Co-0、CoO、Co 3 O 4组成的用于HER和OER的Co-Co氧化物/N掺杂碳杂化材料（CoOx@CN）。CoOx@CN的起始电位为85 mV，电荷转移电阻低（41 Ω），对HER具有较好的稳定性。电催化实验进一步表明，CoOx@CN对HER具有较好的催化性能，这与碳的高导电性、金属钴和钴氧化物的协同效应、碳包覆Co纳米颗粒的稳定性以及富电子氮的引入有关。此外，当用作OER的催化剂时，CoOx@CN杂化物在10 mA cm（-2）的电流密度下需要0.26 V的过电位，这与许多其他非贵金属催化剂相当甚至上级。更重要的是，通过应用CoOx@CN作为阴极和阳极电催化剂，制备了在1.55 V电压下接近20 mA cm（-2）的碱性电解槽，这为探索整体水裂解催化剂开辟了新的可能性。
Remarkable hydrogen evolution reaction (HER) or superior oxygen evolution reaction (OER) catalyst has been applied in water splitting, however, utilizing a bifunctional catalyst for simultaneously generating H-2 and O-2 is still a challenging issue, which is crucial for improving the overall efficiency of water electrolysis. Herein, inspired by the superiority of carbon conductivity, the propitious H atom binding energy of metallic cobalt, and better OER activity of cobalt oxide, we synthesized cobalt-cobalt oxide/N-doped carbon hybrids (CoOx@CN) composed of Co-0, CoO, Co3O4 applied to HER and OER by simple one-pot thermal treatment method. CoOx@CN exhibited a small onset potential of 85 mV, low charge-transfer resistance (41 Omega), and considerable stability for HER. Electrocatalytic experiments further indicated the better performance of CoOx@CN for HER can be attributed to the high conductivity of carbon, the synergistic effect of metallic cobalt and cobalt oxide, the stability of carbon-encapsulated Co nanoparticles, and the introduction of electron-rich nitrogen. In addition, when used as catalysts of OER, the CoOx@CN hybrids required 0.26 V overpotential for a current density of 10 mA cm(-2), which is comparable even superior to many other non-noble metal catalysts. More importantly, an alkaline electrolyzer that approached similar to 20 mA cm(-2) at a voltage of 1.55 V was fabricated by applying CoOx@CN as cathode and anode electrocatalyst, which opened new possibilities for exploring overall water splitting catalysts.