Hussain Shabbir, Aslam Ammara, Tajammal Affifa, Othman Fezah, Mustafa Zeeshan, Alsuhaibani Amnah Mohammed, Refat Moamen Salaheldeen, Shahid Muhammad, Sagir Muhammad, Zakaria Zainul Amiruddin
Institute of Chemistry, Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan 64200, Pakistan.
Department of Chemistry, Lahore Garrison University, DHA Phase VI, Lahore 54792, Pakistan.
ACS Omega. 2024 Aug 5;9(33):35408-35419. doi: 10.1021/acsomega.4c01328. eCollection 2024 Aug 20.
MnO nanoparticles (NPs) find diverse applications in the fields of medicine, biomedicine, biosensors, water treatment and purification, electronics, electrochemistry, and photoelectronics. The production of MnO NPs was reported earlier through various physical, chemical, and green routes, but no studies have still been performed on their biosynthesis from . We synthesized manganese oxide NPs, i.e., (MnO) and (MnO) NPs, by utilizing leaves and petals, respectively, of as reducing and stabilizing agents. The investigated green path is eco-friendly and does not involve any hazardous raw materials. The structural properties of NPs were determined by X-ray diffraction (XRD) analysis, spectroscopies (Fourier transform infrared (FTIR), Raman, and UV-visible), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The NPs were also evaluated for their electrochemical properties by cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD). XRD analysis was performed to verify their tetragonal geometry, and the crystallite size (19.24 nm) of (MnO) was smaller than that (20.84 nm) of (MnO) NPs. SEM images displayed a porous and spherical morphology with a diameter of 14-35 nm. FTIR spectra of (MnO) and (MnO) displayed Mn-O vibrations at 605.69 and 616.87 cm, respectively, and the hydrous nature of the material. Raman spectroscopy revealed the existence of tetrahedral and octahedral units along with A, T, and E active modes of MnO and 2TO mode. UV-visible analyses of (MnO) and (MnO) NPs showed absorption peaks at 272.3 and 268.8 nm, along with band gaps of 4.83 and 5.49 eV, respectively. TGA curves displayed good thermal stabilities up to 600 °C and a loss of moisture content. DSC curves exhibited exothermic/endothermic peaks with glass transition temperatures of 258.9 and 308.7 °C for (MnO) and (MnO), respectively. The CV curves showed redox peaks and confirmed that the electrochemical reaction takes place in the MnO material. GCD scans revealed the capacitive behavior of NPs and their suitability as electrodes in energy storage devices. However, (MnO) will act as a good material for energy storage applications as compared to (MnO) NPs. The synthesized NPs were also tested for their antibacterial efficacy by biofilm inhibition and agar well diffusion methods. The NPs showed higher activities against (Gram-positive) than against (Gram-negative), and (MnO) was more bioactive than (MnO).
二氧化锰纳米颗粒（NPs）在医学、生物医学、生物传感器、水处理与净化、电子学、电化学和光电子学等领域有多种应用。此前已有通过各种物理、化学和绿色途径制备二氧化锰纳米颗粒的报道，但尚未有关于从……进行生物合成的研究。我们分别利用……的叶子和花瓣作为还原剂和稳定剂，合成了氧化锰纳米颗粒，即（MnO）和（MnO）纳米颗粒。所研究的绿色途径是环保的，不涉及任何危险原料。通过X射线衍射（XRD）分析、光谱学（傅里叶变换红外（FTIR）、拉曼和紫外可见）、扫描电子显微镜（SEM）、热重分析（TGA）和差示扫描量热法（DSC）来确定纳米颗粒的结构性质。还通过循环伏安法（CV）和恒电流充放电（GCD）对纳米颗粒的电化学性质进行了评估。进行XRD分析以验证其四方几何结构，（MnO）的微晶尺寸（19.24 nm）小于（MnO）纳米颗粒的微晶尺寸（20.84 nm）。SEM图像显示出直径为14 - 35 nm的多孔球形形态。（MnO）和（MnO）的FTIR光谱分别在605.69和616.87 cm处显示出Mn - O振动以及材料的含水性质。拉曼光谱揭示了四面体和八面体单元的存在以及MnO的A、T和E活性模式和2TO模式。（MnO）和（MnO）纳米颗粒的紫外可见分析显示在272.3和268.8 nm处有吸收峰，带隙分别为4.83和5.49 eV。TGA曲线显示在高达600°C时具有良好的热稳定性以及水分含量的损失。DSC曲线分别显示（MnO）和（MnO）的玻璃化转变温度为258.9和308.7°C时的放热/吸热峰。CV曲线显示出氧化还原峰，并证实了MnO材料中发生了电化学反应。GCD扫描揭示了纳米颗粒的电容行为及其作为储能器件电极的适用性。然而，与（MnO）纳米颗粒相比，（MnO）将作为储能应用的良好材料。还通过生物膜抑制和琼脂孔扩散法测试了合成的纳米颗粒的抗菌功效。纳米颗粒对（革兰氏阳性）的活性高于对（革兰氏阴性）的活性，并且（MnO）比（MnO）具有更高的生物活性。
