Khedr Alaa I, Ali Mohamed H H
National Institute of Oceanography and Fisheries, Cairo, Egypt.
Sci Rep. 2024 Nov 25;14(1):29156. doi: 10.1038/s41598-024-79589-4.
This study presents a simple, sustainable, eco-friendly approach for synthesizing copper oxide (CuO) nanoparticles using Citrus aurantium peel extract as a natural reducing and stabilizing agent. The synthesized CuO and CuO-OP were characterized using various techniques, including surface area measurement (S), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX), and high resolution transmission electron microscope (HRTEM). DRS analysis determines band gap energy (E) of 1.7 eV for CuO and 1.6 eV for CuO-OP. FTIR confirmed the presence of Cu-O bond groups. The XRD and HRTEM results revealed monoclinic and spherical nanostructures, with average particle sizes ranging from 53.25 to 68.02 nm, as determined via Scherer's equation. EDX analysis indicated incorporation of carbon (1.6%) and nitrogen (0.3%) from the peel extract. The synthesized CuO and CuO-OP NPs exhibited excellent photocatalytic efficiencies for methylene blue dye under UV irradiation, reaching 95.34 and 97.5%, respectively, under optimal conditions; the initial dye concentration was 100 mg/L, the pH was 10, the catalyst dosage was 1 g/L, and the contact time was 120 min. Isothermal studies showed that the adsorption of MB onto the nanoparticles followed the Freundlich isotherm model (R = 0.97 and 0.96). Kinetic studies indicated that the degradation followed pseudo-first-order kinetics, with rate constants (K) of 0.0255 min for CuO and 0.033 min for CuO-OP. The sorption capacities were calculated as 98.19 mg/g for CuO and 123.1 mg/g for CuO-OP. The energy values obtained from the Dubinin-Radushkevich isotherm were 707.11 and 912.87 KJ mol, suggesting that chemisorption was the dominant mechanism.
本研究提出了一种简单、可持续、环保的方法，以酸橙皮提取物作为天然还原剂和稳定剂来合成氧化铜（CuO）纳米颗粒。使用多种技术对合成的CuO和CuO-OP进行了表征，包括表面积测量（S）、X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、漫反射光谱（DRS）、扫描电子显微镜（SEM）结合能量色散X射线光谱（EDX）以及高分辨率透射电子显微镜（HRTEM）。DRS分析确定CuO的带隙能量（E）为1.7 eV，CuO-OP的带隙能量为1.6 eV。FTIR证实了Cu-O键基团的存在。XRD和HRTEM结果揭示了单斜和球形纳米结构，通过谢乐方程确定平均粒径范围为53.25至68.02 nm。EDX分析表明从皮提取物中引入了碳（1.6%）和氮（0.3%）。合成的CuO和CuO-OP纳米颗粒在紫外光照射下对亚甲基蓝染料表现出优异的光催化效率，在最佳条件下分别达到95.34%和97.5%；初始染料浓度为100 mg/L，pH为10，催化剂用量为1 g/L，接触时间为120分钟。等温研究表明，MB在纳米颗粒上的吸附遵循弗伦德利希等温模型（R = 0.97和0.96）。动力学研究表明，降解遵循准一级动力学，CuO的速率常数（K）为0.0255 min，CuO-OP的速率常数为0.033 min。计算得出CuO的吸附容量为98.19 mg/g，CuO-OP的吸附容量为123.1 mg/g。从杜比宁-拉杜什凯维奇等温线获得的能量值分别为707.11和912.87 KJ mol，表明化学吸附是主要机制。
