Sonkusare Vaishali N, Chaudhary Ratiram Gomaji, Bhusari Ganesh S, Mondal Aniruddha, Potbhare Ajay K, Mishra Raghvendra Kumar, Juneja Harjeet D, Abdala Ahmed A
Post Graduate Teaching Department of Chemistry, Rashtrasant Tukdoji Maharaj Nagpur University, Nagpur 440033 (Maharashtra), India.
Post Graduate Department of Chemistry, Seth Kesarimal Porwal College of Arts, Science and Commerce, Kamptee 441001 (Maharashtra), India.
ACS Omega. 2020 Apr 1;5(14):7823-7835. doi: 10.1021/acsomega.9b03998. eCollection 2020 Apr 14.
The present article reports a facile approach to fabrication of mesoporous octahedron-shaped tricobalt tetroxide nanoparticles (CoO NPs) with a very narrow size distribution for eco-friendly remediation of toxic dyes. CoO NPs were fabricated by a solgel process using cobalt chloride hexahydrate (CoCl·6HO) and monosodium succinate (CHONa) as a chelating/structure-directing agent and sodium dodecyl sulfate as a surfactant. Moreover, the phase structure, elemental composition, and thermal and morphological facets of CoO NPs were investigated using XRD, FT-IR, EDS, Raman, XPS, TGA, SEM, and TEM techniques. The face-centered cubic spinel crystalline structure of the CoO NPs was confirmed by XRD and SEM, and TEM analysis revealed their octahedron morphology with a smooth surface. Moreover, the narrow pore size distribution and the mesoporous nature of the CoO NPs were confirmed by Brunauer-Emmett-Teller measurements. The photocatalytic activity of CoO NPs for degradation of methyl red (MR), Eriochrome Black-T (EBT), bromophenol blue (BPB), and malachite green (MG) was examined under visible light irradiation, and the kinetics of the dye degradation was pseudo-zero-order with the rate constant in the order of MR > EBT > MG > BPB. Furthermore, the mechanism of photo-disintegration mechanism of the dye was examined by a scavenging test using liquid chromatography-mass chromatography, and its excellent photodegradation activities were attributed to the photogenerated holes (h), superoxide (O ) anions, and hydroxyl (OH) radicals. Finally, the synergistic effect of the nano-interconnected channels with octahedron geometry, mesoporous nature, and charge transfer properties along with photogenerated charge separations leads to an enhanced CoO photocatalytic activity.
本文报道了一种简便的方法来制备介孔八面体形状的四氧化三钴纳米颗粒（CoO NPs），其尺寸分布非常窄，用于对有毒染料进行环保修复。通过溶胶 - 凝胶法，使用六水合氯化钴（CoCl·6H₂O）和丁二酸钠（C₄H₄Na₂O₄）作为螯合/结构导向剂，以及十二烷基硫酸钠作为表面活性剂来制备CoO NPs。此外，使用XRD、FT - IR、EDS、拉曼光谱、XPS、TGA、SEM和TEM技术研究了CoO NPs的相结构、元素组成以及热学和形态学方面。XRD和SEM证实了CoO NPs的面心立方尖晶石晶体结构，TEM分析揭示了它们具有光滑表面的八面体形态。此外，Brunauer - Emmett - Teller测量证实了CoO NPs的窄孔径分布和介孔性质。在可见光照射下考察了CoO NPs对甲基红（MR）、铬黑T（EBT）、溴酚蓝（BPB）和孔雀石绿（MG）的光催化降解活性，染料降解动力学为准零级，速率常数顺序为MR > EBT > MG > BPB。此外，通过液相色谱 - 质谱联用的清除试验研究了染料的光分解机理，其优异的光降解活性归因于光生空穴（h⁺）、超氧（O₂⁻）阴离子和羟基（OH）自由基。最后，纳米互连通道的八面体几何形状、介孔性质和电荷转移特性以及光生电荷分离的协同效应导致CoO光催化活性增强。
