摘要：

利用阳极氧化法在钛片基底上制得TiO₂电极，采用此电极在紫外光的照射下对光电催化降解化学毒剂模拟剂甲基磷酸二甲酯（DMMP）的效果进行了研究。通过场发射扫描电子显微镜、电化学工作站和UV-Vis漫反射光谱仪分别对电极进行了形貌、光电性能和光学性质表征，发现钛片基底上整齐均匀排布着管口直径约为60~80 nm的纳米管阵列，且该电极在紫外光下的光电性能优于可见光下，在200~300 nm的紫外波段下有更强的光学性能。此外，对比了该电极在光催化（PC）、电催化（EC）和光电催化（PEC）3种作用下对DMMP的降解效果，并在PEC作用下初步探索了外加偏压和电解质浓度分别对DMMP降解效果的影响。结果表明，PEC作用下DMMP的降解率高于PC和EC作用下的降解率。原因是在光电协同作用下，外加偏压促进了紫外光催生的电子和空穴分离，使得电极表面的O₂ ^·-和·OH数量增多，极大地提高了催化反应速率。在初步探索实验中得出，外加偏压1.5 V、电解液中Na₂SO₄浓度为0.3 mol/L的条件下，TiO₂电极在光电催化作用下对DMMP的降解效果最佳，降解率达到91.7%。

关键词: TiO₂电极, 光电催化, 化学毒剂模拟剂

Abstract:

TiO₂ electrode prepared on titanium substrate by anodic oxidation method was used to study the photocatalytic degradation of chemical warfare agent simulant dimethyl methphosphate（DMMP） under UV irradiation. The morphology，photoelectric properties and optical properties of the electrode were characterized by field emission scanning electron microscope，electrochemical workstation and UV-Vis diffuse reflectance spectrometer，respectively. It was found that the titanium substrate was neatly and uniformly arranged with a tube diameter of about 60-80 nm，and the photoelectric performance of the electrode under ultraviolet light was better than that under visible light. It had stronger optical properties in the ultraviolet band of 200-300 nm. In addition，the degradation effects of the electrode on DMMP under photocatalytic（PC），electrocatalytic（EC） and photoelectrocatalytic（PEC） were compared，and the effects of external bias voltage and electrolyte concentration on DMMP degradation under the action of PEC were preliminarily explored. The results showed that the degradation rate of DMMP by PEC was higher than that by PC and EC. The reason was that under the photoelectric synergy，the additional bias promoted the separation of electrons and holes induced by ultraviolet light，which increased the amount of O₂ ^·- and ·OH on the electrode surface and greatly improved the catalytic reaction rate. In the preliminary exploratory experiment，it was concluded that under the condition of 1.5 V bias voltage and 0.3 mol/L Na₂SO₄，the degradation effect of DMMP by TiO₂ electrode under the photoelectric catalysis was the best，and the degradation rate reached 91.7%.

Key words: TiO₂ electrode, photoelectrocatalytic, chemical warfare agent simulant

中图分类号: 

• X703

• O643.36