摘要：

通过溶胶-凝胶法制备了颗粒活性炭（GAC）负载过渡金属和氮元素共掺杂改性的TiO₂（X-N-TiO₂/GAC，X=Fe或Cu或Mn），以光电协同催化处理甲基橙废水。阳极为铱钽钛板，阴极为钛板，长弧氙灯作光源，以20 mg/L模拟甲基橙废水在180 min时的降解率为评价指标，优化材料的制备条件和反应电压，并进行SEM和XRD表征。结果表明，锐钛矿型改性TiO₂成功负载到GAC表面，溶胶-凝胶法的负载效果良好，掺杂均匀。在过渡金属离子掺杂方面，与Cu-N-TiO₂/AC和Mn-N-TiO₂/AC相比，Fe-N-TiO₂/AC表现出更高的催化效率。在Fe掺杂量为0.6%、N掺杂量为10%、反应电压为14 V、反应时间为180 min的条件下，甲基橙降解率可达到92.27%，高于光催化降解率（32.81%）和电催化降解率（55.79%），也优于P25光催化的处理效果。Fe和N的掺杂使TiO₂/GAC产生可见光波段的响应。GAC负载后的改性TiO₂虽然光催化效率有所下降，但具有易回收的优点，且可充当粒子电极，在光电协同催化体系中降解污染物，大幅提高降解效率。

关键词: 三维电极, 二氧化钛, 光电催化, 甲基橙, 离子掺杂

Abstract:

Granular activated carbon （GAC） loaded with transition metal and nitrogen co-doped modified TiO₂（X-N-TiO₂/GAC， X=Fe or Cu or Mn） was prepared by sol-gel method to treat methyl orange wastewater by photoelectric synergistic catalysis. The anode was an iridium-tantalum titanium plate， the cathode was a titanium plate， and a long-arc xenon lamp was used as the light source. The degradation rate of 20 mg/L simulated methyl orange wastewater at 180 min was evaluated， and the preparation conditions and reaction voltage of the materials were optimized and characterized by SEM and XRD. The results showed that the anatase type modified TiO₂ was successfully loaded onto the surface of GAC with good loading effect by sol-gel method and uniform doping. In terms of transition metal ion doping， Fe-N-TiO₂/AC exhibited higher catalytic efficiency compared with Cu-N-TiO₂/AC and Mn-N-TiO₂/AC. Under the conditions of 0.6% Fe doping， 10% N doping， 14 V at reaction voltage and 180 min reaction time， the degradation rate of methyl orange could reach 92.27%， which was higher than the photocatalytic degradation rate （32.81%） and electrocatalytic degradation rate （55.79%）， and also better than the treatment effect of P25 photocatalysis. The doping of Fe and N enabled visible wavelength response of TiO₂/GAC. The modified TiO₂ after GAC loading has the advantage of easy recovery although the photocatalytic efficiency decreases， and it can act as a particle electrode to degrade pollutants in the photoelectric synergistic catalytic system， which substantially improves the degradation efficiency.

Key words: three-dimensional electrode, TiO₂, photoelectrocatalytic, methyl orange, ion doping

中图分类号: 

• X703