Fabrication of porous boron-doped diamond electrodes by catalytic etching under hydrogen-argon plasma
Fabrication of porous boron-doped diamond electrodes by catalytic etching under hydrogen-argon plasma
复制标题
氢-氩等离子体催化刻蚀制备多孔掺硼金刚石电极
DOI：
10.1016/j.apsusc.2015.11.028
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发表时间：
2016
影响因子：
6.7
通讯作者：
Baohe Yang
中科院分区：
文献类型：
--
作者：
Chao Shi;Cuiping Li;Mingji Li;Hongji Li;Wei Dai;Yongheng Wu;Baohe Yang
以电沉积Ni纳米颗粒为催化剂，采用氢-氩等离子体刻蚀法制备了多孔掺硼金刚石（BDD）。通过改变刻蚀时间（30 ~ 300 s），研究了多孔BDD的刻蚀过程和形成机理。由于Ni纳米颗粒周围的碳原子容易与氢等离子体反应生成甲烷，从而产生孔隙。随着刻蚀时间的增加，孔径增大，孔密度减小，孔深度先增大后保持不变。随着刻蚀时间的延长，BDD表面的sp2键合石墨碳增加，这是由于比表面积的增加。由于氩等离子体的高能量，没有观察到优先蚀刻。采用循环伏安法（CV）、恒流充放电（GCD）和电化学阻抗谱（EIS）对BDD电极的电化学行为进行了表征。结果表明，多孔BDD电极具有高的比电容，这归因于其高的电导率和大的比表面积。多孔BDD电极的最高比电容为9.55 mF cm-2，比原始BDD电极高22倍。多孔BDD电极的比电容保持率在500次循环后降低到初始电容的98.2%，然后在10，000次循环后增加到120.0%。对于前500个循环，电容的降低可以归因于附着在多孔BDD表面或埋在浅层中的Ni纳米颗粒的溶解。10，000次循环后的电容增加是由于随着循环次数的增加，电解液与残余Ni的接触更好。
Porous boron-doped diamond (BDD) was prepared by hydrogen–argon plasma etching using electrodeposited Ni nanoparticles as a catalyst. The etching process and formation mechanism of porous BDD were investigated by changing the etching time from 30 s to 300 s. Pores were produced due to the C atoms around Ni nanoparticles are easy to react with hydrogen plasma and form methane. With the increase of etching time, the pore size increased, the pore density decreased, and the pore depth first increased and then maintained unchanged. The sp2-bonded graphitic carbons existing on the surface of BDD increase with increasing etching time due to the increase of surface area. No preferential etching was observed due to the high energy of argon plasma. The electrochemical behaviors of the pristine and porous BDD electrodes were characterized by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy (EIS). The results showed that the porous BDD electrode exhibited high specific capacitance, which is attributed to its high electrical conductivity and large specific surface area. The highest specific capacitance of porous BDD electrode is 9.55 mF cm−2, which is 22 times higher than that of pristine BDD electrode. The specific capacitance retention of the porous BDD electrode reduced to 98.2% of the initial capacitance after 500 cycles and then increased to 120.0% after 10,000 cycles. For the first 500 cycles, the reduction of capacitance can be attributed to the dissolution of Ni nanoparticles that attached on the porous BDD surface or buried in the shallow layer. The capacitance increase after 10,000 cycles is due to the better contact of the electrolytic solution with the residual Ni with the increase of cycle number.