Structure and electrochemical characterization of carbon films formed by unbalanced magnetron (UBM) sputtering method
Structure and electrochemical characterization of carbon films formed by unbalanced magnetron (UBM) sputtering method
复制标题
DOI：
10.1016/j.diamond.2014.07.007
复制
发表时间：
2014-10-01
影响因子：
4.1
通讯作者：
Niwa, Osamu
中科院分区：
文献类型：
--
作者：
Kamata, Tomoyuki;Kato, Dai;Niwa, Osamu
我们以前报道过用电子回旋共振（ECR）溅射法制备纳米碳薄膜。薄膜含有由sp(3)和sp(2)键组成的纳米晶结构，表面非常平坦（Ra = 0.07 nm）。该薄膜还具有比玻碳更宽的电位窗口，并且对某些物种具有比硼掺杂金刚石更好的电化学活性。然而，ECR溅射设备比传统溅射设备昂贵得多，并且需要一个环形靶。因此，利用这种方法开发金属-碳杂化膜等新型电极材料比较困难。本文采用非平衡磁控（UBM）溅射设备制备了一种纳米碳膜电极，该电极具有与ECR纳米碳膜相当的电位窗口和电化学活性。该方法使用传统的设备，具有广泛可控的溅射条件，包括高溅射速率、大溅射面积和多材料共溅射能力。通过增加靶与衬底之间的偏置电压，薄膜可以包含最多53%的sp3键，并且具有与ECR纳米碳膜相当的电位窗口。然而，电极表面比ECR纳米碳膜粗糙约一个数量级，这是由于目标表面面对衬底表面而引起的Ar+离子反射的影响。通过透射电镜，我们可以观察到UBM纳米碳膜中石墨烯的纳米晶结构，这是传统类金刚石碳膜中难以观察到的。UBM纳米碳膜对Ru(NH3)(6)（3+）和Fe(CN)(6)（4-）的电子转移速率与ECR纳米碳膜相似，表明纳米晶体结构有助于实现相对较快的电子转移速率。UBM纳米碳薄膜成功地用于检测具有高氧化电位的牛尿酸，这是传统玻碳电极难以检测的。(C) 2014 Elsevier B.V.版权所有
We previously reported nanocarbon films formed by the electron cyclotron resonance (ECR) sputtering method. The films contain a nanocrystalline structure consisting of sp(3) and sp(2) bonds with an extremely flat surface (Ra = 0.07 nm). The film also has a wider potential window than glassy carbon and superior electrochemical activity to boron doped diamond for certain species. However, ECR sputtering equipment is much more expensive than that used for conventional sputtering and requires a ring-shaped target. Therefore, it is difficult to use this method to develop new electrode materials such as metal-carbon hybrid film. Here, we describe a nanocarbon film electrode that we developed with a potential window and electrochemical activity equivalent to those of ECR nanocarbon films by using unbalanced magnetron (UBM) sputtering equipment Our approach uses conventional equipment and has widely controllable sputtering conditions including a high sputtering rate, a large sputtering area and the capacity for co-sputtering multiple materials. The film can contain a maximum of 53% sp3 bonds by increasing the substrate bias voltage between the target and substrate, and also exhibits a potential window equivalent to that of the ECR nanocarbon film. However, the electrode surface is about one order of magnitude rougher than that of the ECR nanocarbon film due to the effect of reflected Ar+ ions caused by the fact that the target surface is facing the substrate surface. By employing transmission electron microscopy, we could observe nanocrystalline graphene structures in the UBM nanocarbon film, which are difficult to observe in conventional diamond-like carbon film. The electron transfer rate at the UBM nanocarbon film is similar to those of ECR nanocarbon film for Ru(NH3)(6)(3+) and Fe(CN)(6)(4-), suggesting that the nanocrystalline structure could contribute to a relatively fast electron transfer rate. The UBM nanocarbon films were successfully used for detecting kynurenic acid, which has a high oxidation potential and is difficult to detect with a conventional glassy carbon electrode. (C) 2014 Elsevier B.V. All rights reserved.