Scalable and controlled creation of nanoholes in graphene by microwave-assisted chemical etching for improved electrochemical properties
Scalable and controlled creation of nanoholes in graphene by microwave-assisted chemical etching for improved electrochemical properties
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DOI：
10.1016/j.carbon.2020.01.076
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发表时间：
2020-05
期刊：
影响因子：
10.9
通讯作者：
Dini Wang;Rui Dai;Xing Zhang;Lei Liu;H. Zhuang;Y. Lu;Yan Wang;Y. Liao;Qiong Nian
中科院分区：
文献类型：
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作者：
Dini Wang;Rui Dai;Xing Zhang;Lei Liu;H. Zhuang;Y. Lu;Yan Wang;Y. Liao;Qiong Nian
石墨烯基面上的纳米孔可以提供丰富的质量传递通道和化学活性位点，从而提高石墨烯的电化学性能。然而，由于传统的体加热策略缺乏促进刻蚀反应的能力，目前用于制造这些纳米孔的热化学刻蚀工艺普遍存在工艺效率、可扩展性和可控性不足的问题。为了解决这一问题，开发了一种利用微波辐射促进和控制石墨烯化学蚀刻的新工艺。在此过程中，微波可以诱导石墨烯在液体溶液中选择性加热，从而促进石墨烯-蚀刻剂界面上发生的蚀刻反应。应用该策略，与传统方法相比，通过控制石墨烯基面上纳米孔的数量和面积百分比，可以显著减少从小时尺度到分钟尺度的处理时间。密度泛函理论和分子动力学模拟表明，纳米孔的形成源于石墨烯基面上预处理空位周围边缘位置原子的循环腐蚀氧化过程。由于可达表面积、离子扩散和非均质电荷转移的改善，所获得的多孔氧化石墨烯片具有优异的电容性能和电化学催化活性。
Nanoholes on the basal plane of graphene can provide abundant mass transport channels and chemically active sites for enhancing the electrochemical performance. However, current thermal chemical etching processes to manufacture these nanoholes commonly suffer from insufficient process efficiency, scalability and controllability, due to the conventional bulk heating strategy lacks capability to promote the etching reactions. To address this issue, a novel process is developed using microwave irradiation to promote and control the chemical etching of graphene. In this process, the microwave can induce a selective heating of graphene in the liquid solution and then facilitate the etching reactions occurring on the graphene-etchant interface. Applying this strategy, a remarkable reduction of processing time from hour-scale to minute-scale compared to the conventional approaches have been achieved with the control of the population and area percentage of nanoholes on the graphene basal plane. Density functional theory and molecular dynamics simulations revealed that the formation of nanoholes originated from the cyclic etchant oxidation process occurring at the edge-sites atoms around pretreated vacancies on graphene basal plane. The obtained holey graphene oxide sheets exhibit excellent capacitive performance and electrochemical catalytic activity due to the improvements in the accessible surface area, ion diffusion, and heterogeneous charge transfer.