School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China.
School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China; Guangxi Key Laboratory of Processing for Non-ferrous Metallic and Featured Materials, Guangxi Zhuang Autonomous Region, Nanning 530004, China.
J Hazard Mater. 2020 Jul 15;394:122566. doi: 10.1016/j.jhazmat.2020.122566. Epub 2020 Mar 19.
In this work, using industrial waste red mud (RM) as main starting material, a simple method of mechanochemical synthesis (MCS) was introduced as a green approach to synthesize heterogeneous FeO/Zn-Al layered double hydroxide (F/ZA-LDH), which could be used as a new low-cost catalyst for photo-Fenton reaction. The optimum preparation conditions of F/ZA-LDH were as follows: mass ratio of Zn(NO)·6HO to RM (m:m) 2:1, dry milling time 6 h, HO dosage 2 mL, ball-to-powder mass ratio 50:1, and milling speed 250 rpm. The effects of the synthesis conditions on the crystal structure and catalytic activity of F/ZA-LDH were analyzed. The F/ZA-LDH was characterized by XRD, TG, XPS, SEM, (HR)TEM. The characterization results showed the composite had a crystallized hydrotalcite-like structure, and the crystalline phases in the optimum F/ZA-LDH were FeO and Zn-Al LDH. A hetero-interfaces between FeO and Zn-Al LDH existed in the synthesized FeO/Zn-Al LDH composite. Furthermore, the possible mechanism for F/ZA-LDH formation in the MCS process was proposed. Overall, our results provide a systematic understanding of the preparation of LDH composite through MCS using RM as main material, and our findings help to develop green technology for reusing RM.
在这项工作中，我们使用工业废料赤泥（RM）作为主要起始材料，引入了一种简单的机械化学合成（MCS）方法，作为合成非均相 FeO/Zn-Al 层状双氢氧化物（F/ZA-LDH）的绿色方法，F/ZA-LDH 可用作光芬顿反应的新型低成本催化剂。F/ZA-LDH 的最佳制备条件如下：Zn(NO)·6HO 与 RM 的质量比（m:m）为 2:1，干磨时间为 6 h，HO 用量为 2 mL，球磨比为 50:1，研磨速度为 250 rpm。分析了合成条件对 F/ZA-LDH 晶体结构和催化活性的影响。采用 XRD、TG、XPS、SEM、（HR）TEM 对 F/ZA-LDH 进行了表征。表征结果表明，该复合材料具有结晶水滑石结构，最佳 F/ZA-LDH 中的晶相为 FeO 和 Zn-Al LDH。在合成的 FeO/Zn-Al LDH 复合材料中存在 FeO 和 Zn-Al LDH 之间的异质界面。此外，还提出了 MCS 过程中 F/ZA-LDH 形成的可能机理。总之，我们的研究结果为通过以 RM 为主要原料的 MCS 制备 LDH 复合材料提供了系统的认识，我们的研究结果有助于开发 RM 的绿色再利用技术。
