Hydrothermal synthesis of well crystallized C-8 and diamond nanocrystals and pH-controlled C-8 diamond phase transition
Hydrothermal synthesis of well crystallized C-8 and diamond nanocrystals and pH-controlled C-8 diamond phase transition
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水热合成结晶良好的 C-8 和金刚石纳米晶体以及 pH 控制的 C-8 金刚石相变
DOI：
10.1039/c6ce02635d
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发表时间：
2017
期刊：
影响因子：
3.1
通讯作者：
Fan Jiyang
中科院分区：
文献类型：
--
作者：
Zhang Wenxia;Fan Baolu;Zhang Yumeng;Fan Jiyang
金刚石是一种主要的碳同素异形体，而C8是一种罕见而神秘的碳同素异形体，具有超立方晶体结构，甚至比金刚石密度更大（15%）。关于C8纳米晶体（NC）的性质知之甚少，因为在通常条件下合成的碳NC具有石墨或金刚石晶体结构。我们发展了一种水热法来合成结晶良好的C8（~ 6.1 nm）和金刚石（~ 4.7 nm）纳米碳。合成的碳NC的晶相由初始前体溶液的pH决定：酸性溶液产生金刚石NC，而碱性溶液产生C8 NC。碳NC的这两相可以通过在热条件下将pH从酸性改变为碱性或反之亦然而可逆地彼此转化。
Diamond is a major carbon allotrope, whereas C8 is a rare and mysterious carbon allotrope with a super-cubic crystal structure that is even denser than diamond (by 15%). Little is known about the properties of C8 nanocrystals (NCs) because carbon NCs synthesized under usual conditions have either a graphitic or diamond crystal structure. We develop a hydrothermal method to synthesize well-crystallized C8 (∼6.1 nm) and diamond (∼4.7 nm) NCs. The crystal phase of the synthesized carbon NCs is determined by the pH of the initial precursor solution: acid solution results in diamond NCs while basic solution results in C8 NCs. These two phases of carbon NCs can be reversibly converted to each other by changing the pH from acidic to basic or vice versa under thermal conditions.