基于蛋壳膜基碳点合成CDs/Fe3O4/Ag及其催化还原性能

Synthesis of CDs/Fe3O4/Ag composite based on carbon dot derived from eggshell membrane and its performance of catalytic reduction

摘要:

采用氯化铁、尿素、硝酸银为原料，以碳量子点为还原剂，通过水热和光催化两步法合成了Ag/E-CDs/Fe3O4复合物(ECIA)。用鸡蛋壳膜制备的碳量子点表面含有丰富的COOH、OH和NH2等水溶性基团，利用其表面活性基团，首先合成了E-CDs/Fe3O4，光照条件下Ag粒子进一步沉积于E-CDs/Fe3O4表面。采用XRD、FTIR、SEM、TEM和荧光光谱图(PL)等对产物进行表征。以水体中的对硝基苯酚(4-NP)为模拟污染物，研究了ECIA的催化还原性能。探讨了复合物中含银量、催化剂用量、4-NP初始浓度对催化还原反应的影响。结果表明，E-CDs/Fe3O4与Ag粒子复合后提高了催化剂的催化活性，但复合物含银量过高会降低催化剂催化活性，其中，硝酸银添加量为2 mg时所得样品ECIA-2活性最佳，对4-NP的催化还原反应符合一级动力学方程，该反应的ki为0.6441 min-1。

Abstract:

Ag/E-CDs/Fe3O4 compounds (ECIA) were synthesized by hydrothermal and photocatalytic two-step process using FeCl3, urea and AgNO3 as raw materials and carbon quantum dots as reducing agent. Carbon quantum dots derived from eggshell membrane (E-CDs) contained abundant water-soluble groups such as COOH, OH and NH2, E-CDs/Fe3O4 was firstly prepared by the rich functional groups of CDs. Ag particles were further deposited onto the surface of E-CDs/Fe3O4 under the light illumination. The products were characterized by XRD、FTIR、SEM、TEM and photoluminescence (PL). The catalytic reduction properties of the as-synthesized Ag/E-CDs/Fe3O4 compound (ECIA) were investigated using 4-nitrophenol as a probe pollutant in water. The effects of silver content, catalytic dose and concentration on 4-NP reduction were investigated. The results showed that the cooperation of E-CDs/Fe3O4 and Ag particles enhance the catalytic activity of catalyst and the excessive increase of silver content will lead to the decrease of reaction rate and material activity. ECIA-2 sample prepared using 2 mg of AgNO3 dosage was optimal, and the reduction and degradation of 4-nitrophenol (4-NP) was in accordance with the first-order kinetic reaction, and ki was 0.6441 min-1.