Li Chunmin, Zhao Jinsheng, Zhang Yusheng
College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252000, China.
CAS Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China.
Nanomaterials (Basel). 2021 Sep 6;11(9):2314. doi: 10.3390/nano11092314.
In this study, the composite of silica-based sandwich-layered zirconium-titanium phosphate was prepared by a layer-by-layer grafting method and its adsorption properties in a diluted solution of Ni ions were specifically researched by the bath experiment method. The field-emission scanning electron microscope (FESEM) results presented the smooth surface morphology of the pristine adsorbent and a rough surface morphology of the adsorbed adsorbent and the energy dispersive analysis (EDS) results ensured the presence of the original metal element (Si, O, Ti, P, Zr) and the captured nickel element on the adsorbent. The Fourier transformed infrared spectroscopy (FTIR) revealed the new band formation of -Si-Ti-O-, -Si-Ti-O-P-, and -Si-Ti-O-P-Zr-O-, which ensured the successful modification of the silica substrate by zirconium-titanium phosphate. The specific surface area and pore size distribution analysis indicated that the pore structure was changed from type-Ⅳ to H2-type and the specific surface area (BET) of the modified composite was 337.881 m/g. In the bath experiment, the optimal pH for adsorbing Ni ions on the composite was ~8 with the equilibrium time 30 min at room temperature and the maximum sorption amount was 50.1 mg/g. The adsorption kinetics of the sorption process were corresponded to the pseudo-second-order kinetic equation and the isothermal adsorption data were fitted well to the Redlich-Peterson Model. Thermodynamic simulation results revealed the species of Ni ions and provided a reasonable pH scope for better removal of the Ni element in wastewater.
在本研究中，采用层层接枝法制备了二氧化硅基夹心层状磷酸锆钛复合材料，并通过静态实验法专门研究了其在稀释镍离子溶液中的吸附性能。场发射扫描电子显微镜（FESEM）结果显示，原始吸附剂表面形态光滑，吸附后的吸附剂表面形态粗糙，能量色散分析（EDS）结果证实了吸附剂上存在原始金属元素（Si、O、Ti、P、Zr）以及捕获的镍元素。傅里叶变换红外光谱（FTIR）显示形成了新的-Si-Ti-O-、-Si-Ti-O-P-和-Si-Ti-O-P-Zr-O-谱带，这确保了磷酸锆钛对二氧化硅基底的成功改性。比表面积和孔径分布分析表明，孔结构从Ⅳ型转变为H2型，改性复合材料的比表面积（BET）为337.881 m²/g。在静态实验中，复合材料吸附镍离子的最佳pH值约为8，室温下平衡时间为30分钟，最大吸附量为50.1 mg/g。吸附过程的吸附动力学符合准二级动力学方程，等温吸附数据与Redlich-Peterson模型拟合良好。热力学模拟结果揭示了镍离子的种类，并为更好地去除废水中的镍元素提供了合理的pH范围。
