Facile Preparation of Ultrathin Co3O4/Nanocarbon Composites with Greatly Improved Surface Activity as a Highly Efficient Oxygen Evolution Reaction Catalyst
Facile Preparation of Ultrathin Co3O4/Nanocarbon Composites with Greatly Improved Surface Activity as a Highly Efficient Oxygen Evolution Reaction Catalyst
复制标题
轻松制备超薄 Co3O4/纳米碳复合材料，其表面活性大大提高，作为高效析氧反应催化剂
DOI：
10.1002/chem.201700225
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发表时间：
2017-03-01
影响因子：
4.3
通讯作者：
Song, Yu-Fei
中科院分区：
文献类型：
--
作者：
Chen, Yanyan;Hu, Jun;Song, Yu-Fei
水的高效催化氧化为分子氧在太阳能燃料和人工光合系统中起着重要作用。在温和条件下开发高活性、低成本的析氧反应催化剂仍然是极具挑战性的。在这里，一种新的复合材料的基础上，2D Co 3 O 4纳米片和还原氧化石墨烯（rGO）的一锅水热策略。在碱性条件下，Co 3 O 4/rGO纳米复合材料具有良好的上级稳定性，其过电位为290 mV，Tafel斜率为68 mAdec（-1），远小于裸Co 3 O 4催化剂的过电位。还使用0 D CS和1D CNT（CS=碳球，CNT =碳纳米管）代替2D rGO进行了广泛的实验。随着纳米碳尺寸的增加，复合材料的过电位逐渐降低，表明复合材料的电化学活性与碳基体的比表面积密切相关。此外，与Co2 +/Co 3+比为1.2的二维Co 3 O 4纳米片相比，Co2 +/Co 3+比为1.4的二维Co 3 O 4/rGO纳米复合材料具有更好的OER性能，因为在实验条件下可以在二维Co 3 O 4/rGO纳米复合材料中形成更多的氧空位。与目前报道的其他含Co 3 O 4的复合材料相比，Co 3 O 4/rGO纳米复合材料具有优异的OER性能。
The efficient catalytic oxidation of water to dioxygen plays a significant role in solar fuel and artificial photosynthetic systems. It remains highly challenging to develop oxygen evolution reaction (OER) catalysts with high activity and low cost under mild conditions. Here, a new composite material is reported based on ultrathin 2D Co3O4 nanosheets and reduced graphene oxides (rGO) by means of a one-pot hydrothermal strategy. The ultrathin Co3O4/rGO nanocomposite shows superior stability under alkaline conditions and exhibits an overpotential of 290mV with a Tafel slope of 68mAdec(-1), which is much smaller than that of bare Co3O4 catalyst. Extensive experiments were also carried out using 0D CS and 1D CNTs (CS=carbon spheres, CNTs=carbon nanotubes) in place of the 2D rGO. The overpotentials of as-prepared nanocomposites decrease with the increase of the dimension of nanocarbons, suggesting the electrochemistry activity is closely related to the surface area of carbon substrates. In addition, compared with ultrathin 2D Co3O4 nanosheets with a Co2+/Co3+ ratio of 1.2, the as-prepared ultrathin Co3O4/rGO nanocomposite with a Co2+/Co3+ ratio of 1.4 contributes to the better OER performance as more oxygen vacancies can be formed in the ultrathin Co3O4/rGO nanocomposite under the experimental conditions. Compared with other Co3O4-containing composite materials reported so far, the ultrathin Co3O4/rGO nanocomposites show excellent OER performance.