Template-free synthesis of Co3O4 nanorings and their catalytic application
Template-free synthesis of Co3O4 nanorings and their catalytic application
复制标题
Co3O4纳米环的无模板合成及其催化应用
DOI：
10.1039/c7ce01916e
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发表时间：
2018-02-07
期刊：
影响因子：
3.1
通讯作者：
Chen, Guangwen
中科院分区：
文献类型：
--
作者：
Chen, Huihui;Yang, Mei;Chen, Guangwen
本论文发展了一种简便、无模板、易于规模化的Co 3 O 4纳米环的制备方法，该方法可分为两个阶段：（1）CoOOH纳米环的形成和（2）CoOOH纳米环在空气中的高温煅烧。合成Co 3 O 4纳米环的关键步骤是形成CoOOH纳米环，该纳米环是通过在强碱性条件下用H2 O2氧化β-Co（OH）（2）纳米片制备的。CoOOH纳米环形成的合理生长机制与Ostwald熟化有关。结果表明，H_2O_2的用量对CoOOH纳米环的形成起着至关重要的作用。在很大程度上，其他实验变量包括H2 O2浓度，Co2+浓度，Co2+与OH-的摩尔比和反应温度没有影响CoOOH纳米环的制备。此外，所制备的Co 3 O 4纳米环表现出优越的上级活性相比，Co 3 O 4纳米片和商业Co 3 O 4对H2 O2的催化分解。所得Co 3 O 4纳米环的表观速率常数为0.38 min（-1），是Co 3 O 4纳米片的2.2倍。
A facile, template-free and easily scalable approach has been developed for the preparation of Co3O4 nanorings, which can be divided into two stages: (1) formation of CoOOH nanorings and (2) high-temperature calcination of CoOOH nanorings in air. The key step for the synthesis of Co3O4 nanorings is the formation of CoOOH nanorings, prepared by the oxidation of beta-Co(OH)(2) nanoplates with H2O2 under strong basic conditions. The plausible growth mechanism governing the formation of CoOOH nanorings was correlated with Ostwald ripening. It was found that the dosage of H2O2 played a vital role in the formation of CoOOH nanorings. To a large extent, other experimental variables including the H2O2 concentration, Co2+ concentration, the molar ratio of Co2+ to OH-and the reaction temperature did not affect the preparation of the CoOOH nanorings. Furthermore, the as-prepared Co3O4 nanorings exhibited superior activity in comparison with Co3O4 nanoplates and commercial Co3O4 towards the catalytic decomposition of H2O2. The apparent rate constant of the as-prepared Co3O4 nanorings was 0.38 min(-1), which is 2.2 times the value of Co3O4 nanoplates.