Data publication: Dual wetting electrode surfaces for alkaline water electrolysis

Tuning the electrode surfaces for better bubble management is a promising approach to increase the efficiency of alkaline water electrolysis. Therefore, Direct Laser Writing was used to structure Nickel electrodes with a dual wetting surface. The applied pillar-like structure combines superhydrophilic behavior and strong spreading of the liquid across the electrode with hydrophobic bubble nucleation sites. In addition, the electrochemically active surface area is increased by a factor of 9. As a result, the overpotential has been significantly reduced, while the size of the detached bubble has increased. The present data set compares three different electrodes, a non-structured reference electrode and two laser structured electrodes with different depths of the structure, at applied current densities of<strong> <em>j</em> = -20, -50 and -100 mA/cm²</strong> in terms of electrode potential, detached bubble size and number of nucleation sites. As electrolyte <strong>1 M KOH</strong> was used. All experiments were carried out under ambient conditions (<strong><em>T</em> = 293 K,<em>p</em> = 1 bar</strong>).

<strong>Description of <em>Data.zip</em>:</strong>

An overview of all performed experiments is given in the file <strong><em>Summary.csv</em></strong>. The data is analyzed as described in the corresponding journal publication <strong><em>Dual wetting electrode surfaces for alkaline water electrolysis</em></strong>. Each data set is stored in a .hdf5-file, with the relevant metadata incorporated into the attributes assigned to the groups/datasets within the .hdf5-file. The data files are structured in groups as follows:

Electrochemical Measurement Data

Galvanostatic Measurement Data
CV double-layer capacitance
LSV onset potential

Results

Detected Bubbles Sideview

<em>Sideview Raw Images (only for <strong>SH2_LS_Pil_01.hdf5</strong>)</em>

With the exception of a single comprehensive data set comprising unprocessed images (<strong>SH2_LS_Pil_01.hdf5</strong>), the remaining raw images from all performed measurements can be made available upon request.

通过调控电极表面以实现更优异的气泡管理，是提升碱性水电解效率的极具潜力的技术路径。为此，本研究采用直写激光加工（Direct Laser Writing）技术，对镍电极进行结构化处理，制备出兼具双重浸润特性的电极表面。所采用的柱状结构可使电极表面同时具备超亲水特性与电解液的充分铺展能力，同时为气泡提供疏水型形核位点。此外，该结构将电化学活性比表面积提升了9倍。实验结果显示，电极过电位显著降低，而脱离气泡的尺寸则有所增大。

本数据集对比了三类电极：一类为未结构化的参比电极，另外两类为具有不同结构深度的激光结构化电极。测试时施加的电流密度为$j = -20、-50和-100 mathrm{mA/cm^2}$，评估指标包括电极电位、脱离气泡尺寸以及形核位点数量。实验采用1 M氢氧化钾（KOH）溶液作为电解液，所有实验均在环境条件下开展（$T = 293 mathrm{K}，p = 1 mathrm{bar}$）。

### Data.zip 文件说明
所有已完成实验的总览信息收录于Summary.csv文件中。数据集的分析方法详见对应期刊论文《用于碱性水电解的双重浸润电极表面（Dual wetting electrode surfaces for alkaline water electrolysis）》。每份数据集均存储于.hdf5格式文件中，相关元数据已嵌入至.hdf5文件内各组/数据集对应的属性字段中。数据文件按以下分组结构组织：
1. 电化学测量数据
- 恒电流测量数据
- 循环伏安双电层电容
- 线性扫描伏安法起始电位
2. 检测气泡侧视图结果
- 侧视图原始图像（仅包含于SH2_LS_Pil_01.hdf5文件中）

除包含未处理图像的单份综合数据集SH2_LS_Pil_01.hdf5外，其余所有实验的原始图像可根据需求另行提供。