Abstract:
Efficient catalytic reduction of 4-nitrophenol (4-NP) is one focus of industry and practical engineering, because 4-NP is one of the most important sources of pollution of the ecological environment and human health. Here, coassembled hybrid composites of pillar[5]arene (P5A) and gold nanoparticles (Au NPs) were successfully developed by a one-step synthetic method as a type of water-insoluble catalyst for the reduction of 4-NP. The geometric and topological structures, as well as physiochemical properties of Au NPs/P5A composite catalyst, were fully characterized and analyzed through various tests such as transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR), indicating that Au NPs were well dispersed on the surface of the two-dimensional film of assembled P5A. The influence factors of the catalytic reduction of 4-NP were further investigated and discussed, confirming that the content of Au NPs and the concentration of 4-NP were very significant during the catalysis. The catalytic reaction was carried out at the catalyst concentration of 100 mg·L-1 and an initial 4-NP concentration of 90 mg·L-1 under 30 °C. The calculated reaction rate constant was 0.3959 min-1 and the reduction rate of 4-NP was more than 95% in 20 min. In addition, the as-prepared catalyst can maintain a high catalytic efficiency after five cycles. Thus, the easily recyclable composite catalyst with poor aqueous solution can exhibit prospective application to the treatment of 4-NP in water.
摘要:
4-硝基苯酚(4-NP)的高效催化还原是工业和实际工程研究的热点之一。因为4-NP是生态环境和人类健康最重要的污染源之一。这里,通过一步合成方法成功开发了柱[5]芳烃(P5A)和金纳米颗粒(AuNPs)的共组装混合复合材料,作为一种用于还原4-NP的水不溶性催化剂。几何和拓扑结构,以及AuNPs/P5A复合催化剂的理化性质,通过透射电子显微镜(TEM)等各种测试进行了充分的表征和分析,X射线衍射(XRD)和傅里叶变换红外光谱(FTIR),这表明AuNP很好地分散在组装的P5A的二维膜的表面上。对4-NP催化还原的影响因素进行了进一步的研究和讨论,证实了在催化过程中AuNP的含量和4-NP的浓度非常显著。在30°C下,在100mg·L-1的催化剂浓度和90mg·L-1的初始4-NP浓度下进行催化反应。计算的反应速率常数为0.3959min-1,4-NP在20min内的还原率大于95%。此外,所制备的催化剂在5次循环后仍能保持较高的催化效率。因此,易回收的复合催化剂水溶液较差,可用于水中4-NP的处理。