School of Chemical Engineering, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Gyeongbuk, 38541, South Korea.
Research Institute of Cell Culture, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Gyeongbuk, 38541, South Korea.
Sci Rep. 2022 Jun 15;12(1):10017. doi: 10.1038/s41598-022-14117-w.
Different approaches have been developed for the synthesis of various nanostructured materials with unique morphologies. This study demonstrated the photocatalytic and antimicrobial abilities of silver-loaded zinc oxide nanocomposites (Ag@ZnO NCs). Initially, ZnO with a unique mesoporous ellipsoidal morphology in the size range of 0.59 ± 0.11 × 0.33 ± 0.09 µm (length × width) was synthesized using aqueous precipitation in a mild hydrothermal condition (80 °C) with the aqueous fruit extract of goji berry (GB) (as an additive) and calcined in air at 200 °C/2 h and 250 °C/3 h. Powder X-ray diffraction (XRD) revealed the formation of a hexagonal phase of the wurtzite (WZ) structure. The average crystallite size of ZnO was 23.74 ± 4.9 nm as calculated using Debye-Scherrer's equation. It also possesses higher thermal stability with the surface area, pore volume, and pore size of 11.77 m/g, 0.027 cm/g, and 9.52 nm, respectively. Furthermore, different mesoporous Ag@ZnO NCs loaded with face-centered cubic (fcc) silver nanoparticles (Ag NPs) in the range of 90-160 nm were synthesized by GB extract as a reducing and capping agent on the surface of ZnO after calcination in air. The immobilization of Ag NPs was confirmed by XRD, X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), FE-transmission electron microscopy (FE-TEM), and energy-dispersive X-ray spectroscopy (EDS). It was found that Ag@ZnO NC (0.2 wt% of Ag) showed excellent photocatalytic degradation of both methylene blue (MB) (cationic) and congo red (CR) (anionic) dyes under simulated solar irradiation. The photocatalytic degradation of 99.3 ± 0.35% MB and 98.5 ± 1.3% CR occurred in 90 and 55 min, respectively, at room temperature by Ag@ZnO NC. Besides, these NCs also showed broad-spectrum antibacterial activity against both Gram-positive and Gram-negative bacteria. The mechanistic concept of generating reactive oxygen species (ROS) by electron and hole charge (e‾/h) carriers seems to be responsible for the photocatalytic degradation of commercial dyes and antibacterial activities by Ag@ZnO NCs. Thus, these silver-loaded mesoporous ellipsoidal ZnO NCs are promising candidates as photocatalysts for industrial/wastewater treatment as well as in antimicrobial therapeutics.
已经开发出了多种方法来合成具有独特形貌的各种纳米结构材料。本研究展示了负载银的氧化锌纳米复合材料（Ag@ZnO NCs）的光催化和抗菌能力。首先，使用水热法（80°C），在水溶液中添加枸杞（GB）的水果提取物，合成了具有独特介孔椭球形形貌的 ZnO，其尺寸范围为 0.59±0.11×0.33±0.09μm（长度×宽度），然后在空气中于 200°C/2 h 和 250°C/3 h 下煅烧。粉末 X 射线衍射（XRD）表明形成了六方相纤锌矿（WZ）结构。使用德拜-谢勒公式计算，ZnO 的平均晶粒尺寸为 23.74±4.9nm。它还具有更高的热稳定性，比表面积、孔体积和孔径分别为 11.77m/g、0.027cm/g 和 9.52nm。此外，通过 GB 提取物作为表面的还原剂和封端剂，在空气中煅烧后，负载有面心立方（fcc）银纳米颗粒（Ag NPs）的不同介孔 Ag@ZnO NCs 被合成，其尺寸范围为 90-160nm。Ag NPs 的固定化通过 XRD、X 射线光电子能谱（XPS）、场发射扫描电子显微镜（FE-SEM）、场发射透射电子显微镜（FE-TEM）和能谱（EDS）得到证实。结果发现，Ag@ZnO NC（Ag 含量为 0.2wt%）在模拟太阳光照射下对亚甲基蓝（MB）（阳离子）和刚果红（CR）（阴离子）染料表现出优异的光催化降解性能。在室温下，Ag@ZnO NC 分别在 90 和 55min 内使 99.3±0.35%的 MB 和 98.5±1.3%的 CR 完全降解。此外，这些 NCs 还对革兰氏阳性菌和革兰氏阴性菌表现出广谱的抗菌活性。电子和空穴载流子（e‾/h）产生活性氧物种（ROS）的机制概念似乎是 Ag@ZnO NC 光催化降解商用染料和抗菌活性的原因。因此，这些负载银的介孔椭球形 ZnO NC 有望成为工业/废水处理中的光催化剂，以及抗菌治疗中的候选材料。
