不同基底BDD电极对模拟染料废水的降解脱色试验

Experiment of Degradation and Decolouration for Simulated Dye Wastewater Treatment with Different Kinds of Substrates Based Boron Doped Diamond (BDD) Thin-Film Electrode

在Si、Ta、SiC、Ti四种不同的基底上通过热丝化学气相沉积法分别生长了掺硼金刚石(BDD)薄膜。试验对BDD膜层的微观形貌、电极的电化学性能进行了研究。四种基底的BDD电极均具有较宽的电位窗口;Ta-BDD和SiC-BDD晶体形貌完整;Ta-BDD和Ti-BDD具有较好的膜基附着力,具有较长的寿命。试验表明,使用12 h后,Ta-BDD与Ti-BDD仍具有良好的电解性能,微观形貌完整,而Si-BDD和SiC-BDD分别使用4h和6 h后,膜层便开始脱落。试验测定了Ta-BDD电极对活性艳红X-3B模拟染料废水的降解脱色效果,考察了不同条件(槽电压、电解质浓度、电解质种类及pH)对脱色效果的影响。结果表明:在酸性介质中,当硫酸钠浓度为2.5 g/L时,经过120 min电解,模拟废水中的染料可脱除至1%以下。NaCl作为支持电解质时,相比于Na2SO4对废水色度的脱除具有更强的作用。

Boron doped diamond （BDD） thin-film is deposited on 4 kinds of substrates （Si／Ta^SiC／Ti） using hot-filament chemical vapor deposition method. They were characterized by scanning electrical microscopy for properties of microstructure, and cyclic voltammetry for electrochemical properties, respectively. The results show that all four BDD thin-film electrodes have wide potential windows than graphite electrode and RuO2 electrode. Ta based BDD and SiC based BDD have fine morphological features. Ta based BDD and Ti based BDD have firm adhesion properties to the substrates and have long life-time. After electrolysis for 12 h, the film on each electrode still has a good electrolysis performance. However, the films Si based BDD and SiC based BDD started to break af- ter 4 and 6 h, respectively. Simulated Reactive Brilliant Red X-3B wastewater was further treated using Ta based BDD thin-film electrode. Different treatment parameters, for example, voltages, concentrations of electrolyte, types of electrolyte, and pH, have been optimized. The color removal efficiency of 99 % was obtained by electrolysis after 120 min with 2.5 g/L Na2SO4 in acid condition. Comparing with traditional Na2SO4, NaCI is a better electrolyte.