Department of Chemistry, Federal University of Technology, PMB 65, Minna, Niger State, Nigeria.
Nanotechnology Research Group, Centre for Genetic Engineering and Biotechnology (CGEB), Federal University of Technology, PMB 65, Bosso, Minna, Niger State, Nigeria.
Environ Sci Pollut Res Int. 2019 Jul;26(19):19942-19967. doi: 10.1007/s11356-019-05124-y. Epub 2019 May 16.
In this work, AgO/BO/TiO ternary nanocomposite was synthesized by a combination of green and precipitation method involving mixing of different concentrations of silver nitrate, boric acid, and titanium (IV) isopropoxide precursor with Plumeria acuminate leaf extract. The extract was obtained by boiling the mixture of distilled water and the powdered leaves in a beaker for few minutes followed by filtration. The microstructure, morphology, chemical composition, surface area, phase structure, and optical properties of the various prepared nanomaterials were determined by HRTEM, HRSEM, UV-Vis/DRS, BET, XRD, and XPS. The photocatalytic potential of TiO nanoparticles and AgO/BO/TiO nanocomposites to degrade local dyeing wastewater under artificial and natural sunlight irradiation was investigated. The extent of degradation of the organic pollutants was measured using chemical oxygen demand (COD) and total organic carbon (TOC) as indicator parameters. The XRD pattern of AgO/BO/TiO nanocomposites revealed that the formation of pure anatase TiO phase and the addition of both silver and boron precursors did not influenced the phase structure of the nanocomposites. The oxidation states of +1 and +3 for both Ag and B on the surface of AgO/BO/TiO nanocomposites were confirmed by XPS. Optical characterization of the sample revealed reduction of band gap energy from 2.6 to 2.0 eV for TiO and AgO/BO/TiO, respectively. The AgO/BOTiO nanocomposites demonstrated excellent photocatalytic activity under natural sunlight and artificial light than mono and binary oxide systems with TOC and COD degradation efficiencies of 86.11% and 75.69%, respectively. The kinetics of degradation of organic dyes in the wastewater followed the order of Langmuir-Hinshelwood pseudo-first-order > Freundlich > Zero > Parabolic diffusion model. The coupling effect of AgO and BO onto TiO framework was responsible for the enhanced photochemical stability of the nanocomposites even after five repeated cycles.
在这项工作中，通过绿色和沉淀法的结合合成了 AgO/BO/TiO 三元纳米复合材料，该方法涉及将不同浓度的硝酸银、硼酸和钛（IV）异丙醇前体与鸡蛋花叶提取物混合。提取物是通过将蒸馏水和粉末状叶子的混合物在烧杯中煮沸几分钟，然后过滤得到的。通过 HRTEM、HRSEM、UV-Vis/DRS、BET、XRD 和 XPS 确定了各种制备的纳米材料的微观结构、形貌、化学成分、比表面积、相结构和光学性质。研究了 TiO 纳米粒子和 AgO/BO/TiO 纳米复合材料在人工和自然光照射下降解当地染料废水的光催化潜力。使用化学需氧量（COD）和总有机碳（TOC）作为指示参数来测量有机污染物的降解程度。AgO/BO/TiO 纳米复合材料的 XRD 图谱表明，形成了纯锐钛矿 TiO 相，并且添加银和硼前体都不会影响纳米复合材料的相结构。XPS 证实了 AgO/BO/TiO 纳米复合材料表面上 Ag 和 B 的氧化态分别为+1 和+3。样品的光学特性表明，TiO 和 AgO/BO/TiO 的带隙能分别从 2.6 降低到 2.0 eV。AgO/BOTiO 纳米复合材料在自然光和人工光下表现出优异的光催化活性，TOC 和 COD 降解效率分别为 86.11%和 75.69%。废水有机染料的降解动力学遵循 Langmuir-Hinshelwood 拟一级动力学>Freundlich>零>抛物线扩散模型的顺序。AgO 和 BO 偶联到 TiO 骨架上的耦合效应是纳米复合材料即使经过五次重复循环后仍具有增强的光化学稳定性的原因。
