Wang Yita, Lin Youchen
Department of Mechanical and Electro-Mechanical Engineering, Ilan University, Yilan City 26047, Taiwan.
Nanomaterials (Basel). 2018 Jul 5;8(7):494. doi: 10.3390/nano8070494.
The electro-Fenton (EF) process is a type of electrochemical oxidation process; ·OH radicals are generated on the cathode using electricity and decolorize dye wastewaters. Most studies on EF systems in the past have focused on the operating parameters of this process. In recent years, the influence of electrode performance on the EF process has begun to receive more attention. In this study, direct nitridation was used to prepare titanium nitride powders, which were thereafter coated on an SUS304 stainless steel substrate. The performance of this system in the treatment of rhodamine B dye wastewaters via the EF process was investigated. The experimental methods used in this work include: (1) scanning electron microscopy (SEM); (2) X-ray diffraction (XRD); (3) electrochemical Tafel curves; (4) linear sweep voltammetry (LSV); (5) and cyclic voltammetry (CV). It was shown that high-purity TiN can be formed at nitriding temperatures above 900 °C, and the strength of the (111) crystal plane increases with the increase in nitriding temperature; the TiN coating effectively activates the reactive surface of the electrode owing to its porous structure. In terms of corrosion resistance, the corrosion potential and corrosion current of the TiN 1000 °C/SUS304 electrode were 116.94 mV and 205 nA/cm², respectively, and the coating had a coating porosity of 0.89 × 10. As compared with SUS304 stainless steel, the TiN 1000 °C/SUS304 composite electrode had a significantly greater degree of corrosion resistance and exhibited higher redox activity in LSV tests. This composite electrode could achieve a decolorization rate of 49.86% after 30 min, and 94.46% after 120 min. In summary, the TiN 1000 °C/SUS304 composite electrode is very stable and has excellent decolorization efficacy in the EF process. Our findings will serve as a useful reference for future studies on EF electrodes.
电芬顿（EF）工艺是一种电化学氧化工艺；利用电能在阴极上产生·OH自由基，从而使染料废水脱色。过去大多数关于EF系统的研究都集中在该工艺的运行参数上。近年来，电极性能对EF工艺的影响开始受到更多关注。在本研究中，采用直接氮化法制备氮化钛粉末，然后将其涂覆在SUS304不锈钢基底上。研究了该系统通过EF工艺处理罗丹明B染料废水的性能。本工作中使用的实验方法包括：（1）扫描电子显微镜（SEM）；（2）X射线衍射（XRD）；（3）电化学塔菲尔曲线；（4）线性扫描伏安法（LSV）；（5）循环伏安法（CV）。结果表明，在900℃以上的氮化温度下可形成高纯度TiN，且（111）晶面的强度随氮化温度的升高而增加；TiN涂层因其多孔结构有效地激活了电极的反应表面。在耐腐蚀性方面，TiN 1000℃/SUS304电极的腐蚀电位和腐蚀电流分别为116.94 mV和205 nA/cm²，涂层的孔隙率为0.89×10。与SUS304不锈钢相比，TiN 1000℃/SUS304复合电极具有显著更高的耐腐蚀性，并且在LSV测试中表现出更高的氧化还原活性。该复合电极在30分钟后可实现49.86%的脱色率，120分钟后可实现94.46%的脱色率。总之，TiN 1000℃/SUS304复合电极非常稳定，并且在EF工艺中具有优异的脱色效果。我们的研究结果将为未来EF电极的研究提供有用的参考。
