g-C3N4/Bi12O17Cl2复合物的制备及其光催化性能

以硝酸铋、氯化钠和氢氧化钠为原料用液相沉淀法制备g-C₃N₄/Bi₁₂O₁₇Cl₂复合光催化剂,并用X射线衍射(XRD)、傅里叶红外光谱(FT-IR)、扫描电子显微镜(SEM)、紫外-可见漫反射光谱(UV-Vis DRS)等手段表征其组成、微观形貌和性能,以罗丹明B为模拟污染物研究了在可见光照射下g-C₃N₄对g-C₃N₄/Bi₁₂O₁₇Cl₂复合光催化剂活性的影响及其光催化机理。结果表明,2% (质量分数) g-C₃N₄/Bi₁₂O₁₇Cl₂复合光催化剂的光催化性能最好,见光90 min后对罗丹明B的降解率达到98%。     

Preparation of CoFe2O4–P4VP@Ag NPs as effective and recyclable catalysts for the degradation of organic pollutants with NaBH4 in water

Novel magnetic nanocomposites were prepared successfully through the deposition of Ag nanoparticles onto the Poly(4-vinylpyridine)-functionalized CoFe₂O₄ (CoFe₂O₄–P4VP@Ag NPs) and applied as highly effective and recyclable catalysts. The resulting catalysts were characterized with SEM, TEM, AAS, FTIR, XRD, XPS, VSM and elemental analysis. The catalytic performances of CoFe₂O₄–P4VP@Ag NPs for the removal of rhodamine B (RhB) and ciprofloxacin (Cip) in water were studied as a function of initial pollutant concentration, ionic strength, solution pH, temperature and catalyst dosage. The results showed that nearly 99.4% of RhB (20 mg/L) was decolorized in 20 min with the addition of 0.2 g/L CoFe₂O₄–P4VP@Ag NPs under the help of 10 mM of NaBH₄. 81.5% of Cip (9 mg/L) was removed in 180 min under the same experimental conditions. Furthermore, CoFe₂O₄–P4VP@Ag NPs could be reused for six recycles and easily separated from water. Finally, possible mechanism for the degradation of Cip as a representative of organic pollutants by CoFe₂O₄–P4VP@Ag NPs was proposed.     

纳米化处理对g-C3N4物理性质和光催化性能的影响

采用高压微射流均质处理方法,分别在水和异丙醇介质中对以三聚氰胺为前驱体通过热聚合法制备的本征g-C₃N₄材料进行纳米化处理。通过在紫外光和可见光下降解罗丹明B(RhB)和亚甲基蓝(MB),对纳米片的光催化活性进行研究。结果表明:高压微射流均质纳米化处理不会破坏g-C₃N₄层内结构,却能够有效减小g-C₃N₄的颗粒尺寸、增大其比表面积、暴露更多的活性反应位点以及延长载流子的寿命,从而提高g-C₃N₄材料的光催化活性。此外,纳米化处理能够有效调控g-C₃N₄表面官能团,使水相和异丙醇相氮化碳纳米片表面带相反的电荷,可见光照射下,当纳米化处理次数为8次时,异丙醇相氮化碳在210min内对MB的降解率为49%,水相氮化碳在210min内对RhB的降解率为100%。