开发具有高光催化活性的纳米复合光催化剂,成本效益,一个简单的制备过程,和可扩展性的实际应用是非常感兴趣的。在这项研究中,以不同的质量比(4:1)制备了TiO2DegussaP25纳米颗粒/活性炭(TiO2/AC)纳米复合材料,(3:2),(2:3),和(1:4)通过涉及手动机械撞击的简单过程,超声波辅助混合在乙醇溶液中,纸过滤,和温和的热退火。表征方法包括XRD、SEM-EDS,拉曼,FTIR,XPS,和紫外可见光谱。TiO2/AC质量比对结构的影响,形态学,并与裸TiO2和裸AC进行了比较,系统地研究了光催化性能。TiO2纳米颗粒表现出主要的锐钛矿相和次要的金红石相,微晶尺寸约为21nm,而AC具有石墨和碳的XRD峰,微晶尺寸为49nm。复合材料在微米/亚微米AC颗粒上表现出TiO2纳米颗粒的紧密装饰,得到均匀的TiO2/AC复合材料,正如Ti的均匀分布所证明的那样,O,和C在EDS映射中。此外,拉曼光谱显示了锐钛矿TiO2的典型振动模式(例如,E1g(1),B1g(1),Eg(3))和具有D和G带的碳材料。TiO2/AC与(4:1),(3:2),和(2:3)在光催化降解亚甲基蓝(MB)中具有比TiO2或AC更高的反应速率常数(k)。在调查的材料中,TiO2/AC=4:1在UV-Vis辐照(120mW/cm2)下处理30分钟后,达到了最高的光催化活性,高k为55.2×10-3min-1,MB去除效率为96.6%。TiO2/AC的光催化活性增强是由于AC的高吸附能力和TiO2的高光催化活性的协同作用。此外,TiO2/AC促进光激发电子/空穴(e-/h)对的分离,以降低它们的复合速率,从而增强光催化活性。建议使用质量比为4/1的最佳TiO2/AC复合材料处理具有有机污染物的工业或家庭废水。
The development of nanocomposite photocatalysts with high photocatalytic activity, cost-effectiveness, a simple preparation process, and scalability for practical applications is of great interest. In this study, nanocomposites of TiO2 Degussa P25 nanoparticles/activated carbon (TiO2/AC) were prepared at various mass ratios of (4:1), (3:2), (2:3), and (1:4) by a facile process involving manual mechanical pounding, ultrasonic-assisted mixing in an ethanol solution, paper filtration, and mild thermal annealing. The characterization methods included XRD, SEM-EDS, Raman, FTIR, XPS, and UV-Vis spectroscopies. The effects of TiO2/AC mass ratios on the structural, morphological, and photocatalytic properties were systematically studied in comparison with bare TiO2 and bare AC. TiO2 nanoparticles exhibited dominant anatase and minor rutile phases and a crystallite size of approximately 21 nm, while AC had XRD peaks of graphite and carbon and a crystallite size of 49 nm. The composites exhibited tight decoration of TiO2 nanoparticles on micron-/submicron AC particles, and uniform TiO2/AC composites were obtained, as evidenced by the uniform distribution of Ti, O, and C in an EDS mapping. Moreover, Raman spectra show the typical vibration modes of anatase TiO2 (e.g., E1g(1), B1g(1), Eg(3)) and carbon materials with D and G bands. The TiO2/AC with (4:1), (3:2), and (2:3) possessed higher reaction rate constants (k) in photocatalytic degradation of methylene blue (MB) than that of either TiO2 or AC. Among the investigated materials, TiO2/AC = 4:1 achieved the highest photocatalytic activity with a high k of 55.2 × 10-3 min-1 and an MB removal efficiency of 96.6% after 30 min of treatment under UV-Vis irradiation (120 mW/cm2). The enhanced photocatalytic activity for TiO2/AC is due to the synergistic effect of the high adsorption capability of AC and the high photocatalytic activity of TiO2. Furthermore, TiO2/AC promotes the separation of photoexcited electron/hole (e-/h+) pairs to reduce their recombination rate and thus enhance photocatalytic activity. The optimal TiO2/AC composite with a mass ratio of 4/1 is suggested for treating industrial or household wastewater with organic pollutants.