疏水性光催化剂的制备及其催化动力学

采用十二烷基硫酸钠(SDS)为改性剂对TiO₂进行了疏水改性, FTIR表征表明催化剂表面具有CC和CH烷基疏水基团. 同时采用CuO对催化剂进行了可见光响应改性, UV-Vis表征表明催化剂具有良好的可见光响应性能, 吸收边红移至830nm以上. 三维荧光扫描发现随着CuO和SDS的加入，催化剂的空穴电子分离效果迅速提高. 以硝基苯为处理对象, 考察了体系pH值、污染物初始浓度、催化剂用量和光照强度对光催化反应过程的影响, 建立了动力学模型. 低浓度条件下, 通过模型计算的动力学常数相对误差范围为-16.5％～-4.5％; 高浓度条件下为-11.3％～4.6％.

Preparation and Catalytic Kinetic of Hydrophobic Photocatalytic Catalysts

Sodium dodecyl sulfate (SDS) and copper oxide both were used to modify titanium dioxide photocatalytic catalysts. SDS was used to prepare hydrophobic titanium dioxide. Copper oxide was used to modify the visible light absorption capacity of titanium dioxide. FTIR, UV-Vis and 3-D fluorescence spectra methods were used to characterize the modified titanium dioxide photocatalytic catalysts. The modified titanium dioxide catalysts were used to treat nitrobenzene wastewater. Four factors including pH, initial nitrobenzene concentration, catalysts dosage and light intensity, were researched in a nitrobenzene degradation system that was treated under visible light. FTIR characterization shows that CC and CHfunctional groups appear on the surface of the catalysts. UV-Vis characterization shows that the catalysts modified by copper oxide have excellent visible light response capacity and their absorption edges reach or exceed 830nm. 3-D fluorescence spectra shows that hole-electrons are separated well after copper oxide and/or SDS is added. The speed of nitrobenzene degradation is fastest when pH is 9, the initial nitrobenzene concentration is 500mg/L, the catalyst dosage is 0.2g/L, and light intensity exceeds 2000μW/cm~2. A kinetic model is established based on the results. The relative errors of the kinetic constants obtained by the model are between -16.5% and approximately -4.5% with low initial nitrobenzene concentrations, and between -11.3% and approximately 4.6% with high initial concentrations.