松香基表面活性剂调控制备NiO纳米微球及其吸附刚果红

通过天然产物松香制备松香基表面活性剂,利用该表面活性剂调控晶体生长制备出多级Ni(OH)2纳米结构,并进一步制备成NiO微球。通过FT-IR、NMR、XRD、SEM、TEM等表征确定了NiO的形貌及结构,通过BET等表征测试确定了其为多级多孔的结构。FT-IR、UV研究表明该多级纳米NiO对刚果红具有极高的吸附能力,其最大吸附量为657.89 mg/g,远优于商业NiO(337.18 mg/g)。研究结果表明:在pH值3,质量浓度为50 mg/L刚果红20 mL,吸附剂NiO适宜质量为16.8 mg时,吸附10 min达到平衡,平衡吸附量为50 mg/g。NiO对刚果红的吸附更符合Freundlich模型,吸附容易进行,吸附是吸热过程;吸附动力学符合准二级动力学方程,吸附过程以化学吸附为主。循环5次使用后吸附效率没有明显减弱,对刚果红去除率保持98%。

Preparation of NiO Nanospheres by Rosin-based Surfactants and Their Adsorption of Congo Red

Rosin-based surfactant was prepared from rosin and the surfactant was used to regulate the crystal growth and synthesis Ni(OH)₂ with hierarchical nanostructures.The NiO microspheres were further prepared by using Ni(OH)₂ as the precursor.The structure of NiO was characterized by FT-IR, NMR, XRD, SEM and TEM. The porosity of NiO microspheres was determined by BET. The characterization results of FT-IR and UV showed that the hierarchical structure of NiO microspheres showed very high adsorption capacity for Congo red (CR).The maximum adsorption amount was 657.89 mg/g, which was much better than that of commercial NiO(337.18 mg/g).The results showed that the adsorption reached equilibrium after 10 min and the equilibrium adsorption capacity was 50 mg/g at pH value of 3 when the concentration of Congo red was 50 mg/L and the amount of NiO was 16.8 mg. The NiO adsorption of Congo red was in accordance with the Freundlich model and the adsorption is an endothermic process. The adsorption kinetics conforms to the quasi-second-order kinetic equation. The adsorption process is dominated by chemical adsorption. The adsorption efficiency was not obviously reduced after several cycles. The removal rate of adsorption Congo red was maintained by 98% after recyceling for 5 times.