School of Chemistry and Chemical Engineering, Queen's University Belfast, Belfast, BT9 5AG, Northern Ireland, UK.
Chemistry Department, Faculty of Science - Qena, South Valley University, Qena, 83523, Egypt.
Sci Rep. 2020 Feb 13;10(1):2563. doi: 10.1038/s41598-020-59481-7.
Herein, value-added materials such as activated carbon and carbon nanotubes were synthesized from low-value Miscanthus × giganteus lignocellulosic biomass. A significant drawback of using Miscanthus in an energy application is the melting during the combustion due to its high alkali silicate content. An application of an alternative approach was proposed herein for synthesis of activated carbon from Miscanthus × giganteus, where the produced activated carbon possessed a high surface area and pore volume of 0.92 cm.g after two activation steps using phosphoric acid and potassium hydroxide. The S of the raw biomass, after first activation and second activation methods showed 17, 1142 and 1368 m.g, respectively. Transforming this otherwise waste material into a useful product where its material properties can be utilized is an example of promoting the circular economy by valorising waste lignocellulosic biomass to widely sought-after high surface area activated carbon and subsequently, unconventional multi-walled carbon nanotubes. This was achieved when the activated carbon produced was mixed with nitrogen-based material and iron precursor, where it produced hydrophilic multi-wall carbon nanotubes with a contact angle of θ = 9.88°, compared to the raw biomass. synthesised materials were tested in heavy metal removal tests using a lead solution, where the maximum lead absorption was observed for sample AC-K, with a 90% removal capacity after the first hour of testing. The synthesis of these up-cycled materials can have potential opportunities in the areas of wastewater treatment or other activated carbon/carbon nanotube end uses with a rapid cycle time.
本文利用低价值的芒属木质纤维素生物质合成了增值材料，如活性炭和碳纳米管。芒草在能源应用中的一个显著缺点是由于其高碱硅含量，在燃烧过程中会熔化。本文提出了一种替代方法，用于从芒草中合成活性炭，经过两步磷酸和氢氧化钾活化后，所制备的活性炭具有 0.92cm3/g 的高比表面积和孔体积。原始生物质的 S 值，在第一次和第二次激活方法后分别显示为 17、1142 和 1368m2/g。将这种原本的废料转化为有用的产品，利用其材料特性，可以将废弃的木质纤维素生物质转化为广泛需求的高比表面积活性炭，随后再转化为非常规的多壁碳纳米管，从而实现循环经济。当用氮基材料和铁前体制备的活性炭进行混合时，就可以实现这一点，所制备的亲水多壁碳纳米管的接触角θ=9.88°，与原始生物质相比。所合成的材料在重金属去除测试中用铅溶液进行了测试，在第一个小时的测试后，AC-K 样品的最大铅吸收量达到了 90%。这些升级材料的合成在废水处理或其他具有快速循环时间的活性炭/碳纳米管最终用途领域可能具有潜在的机会。
