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采用共沉淀法制备CO_3~(2–)为层间阴离子的Zn–M–Cr–CO_3–HTLCS(类水滑石)三元类水滑石样品,Zn~(2+)、M~(2+)、Cr~(3+)摩尔比为1.5︰1.5︰1.0,M=Mg、Mn、Co、Ni、Cu。用X射线衍射、红外光谱、热重–差热分析和紫外–可见漫反射光谱等分析技术对三元类水滑石的结构和性质进行表征。结果表明:不同二价金属阳离子取代的5种三元类水滑石都具有水滑石的典型层状结构。取代二价金属阳离子半径越小,晶胞参数a值也越小,三元水滑石热稳定性越好。考察了光照时间和催化剂种类、用量等因素对三元类水滑石光催化降解罗丹明B(RhB)溶液的影响,讨论了光催化降解RhB的反应机理。结果表明:Zn–Ni–Cr–CO_3–HTLCS的光催化性能最好,其用量为0.1 g/50 mL条件下,光照120 min,RhB的降解率达到90.72%,循环使用4次后,对RhB的降解率保持在90%左右,且催化剂晶体结构不变。
The Zn-M-Cr-CO_3-HTLCS (hydrotalcite-like) ternary hydrotalcite samples with CO_3 ~ (2-) intercalated anion were prepared by coprecipitation method. , Cr ~ (3+) molar ratio of 1.5: 1.5: 1.0, M = Mg, Mn, Co, Ni, Cu. The structure and properties of ternary hydrotalcites were characterized by X-ray diffraction, FTIR, TG-DTA and UV-Vis diffuse reflectance spectroscopy. The results show that the five ternary hydrotalcites substituted by different divalent metal cations have the typical layered structure of hydrotalcite. The smaller the radius of the substituted divalent metal cation, the smaller the value of the unit cell a, the better the thermal stability of the ternary hydrotalcite. The effect of photocatalytic degradation of RhB solution on the photocatalytic degradation of RhB was investigated with the illumination time, type of catalyst, dosage and other factors. The results showed that the best photocatalytic activity of Zn-Ni-Cr-CO_3-HTLCS was 0.1 g / 50 mL for 120 min, the degradation rate of RhB was 90.72%, and the degradation rate of RhB The degradation rate remained at 90%, and the catalyst crystal structure unchanged.