Dept. Chem, Kyungpook National University, Daegu, 41566, South Korea.
Dept. Chem, Kyungpook National University, Daegu, 41566, South Korea.
Chemosphere. 2022 Sep;303(Pt 1):134890. doi: 10.1016/j.chemosphere.2022.134890. Epub 2022 May 11.
Elimination of organic dyes from wastewater is very important for our safe environment and sound health. In this work, adsorptive removal of cationic dyes, especially small ones, was investigated with carbonaceous materials to develop a competitive adsorption technology. To improve the performance of metal-organic framework (MOF)-derived carbons (MDCs) in dye adsorption, an MDC, derived from a MOF (MAF-6), was oxidatively functionalized with ammonium persulfate solutions (APSs). Although the porosity of pristine MDC decreased with functionalization via oxidation, functionalized MDCs (FMDCs), especially FMDC(1.0) that was obtained via treating MDC with APS (1.0 M), showed remarkable performances in the adsorption of small cationic dyes like methylene blue (MB) and azure B. For example, FMDC(1.0) had the maximum adsorption capacity (Q) of 625.0 mg/g (for MB) which is larger than any reported value with carbonaceous materials. Moreover, the obtained Q was around 4 and 2 times that of activated carbon with Q of 160 mg/g and MDC with Q of 298 mg/g, respectively. On the contrary, oxidative treatment of MDC was negative in adsorption of an anionic dye such as methyl orange. Moreover, the functionalized MDC was not very effective in the adsorption of cationic dyes with large sizes (like brilliant green, crystal violet, Janus green B, and rhodamine B) because of the limited pore size of the studied adsorbent FMDC(1.0). The remarkable adsorption of MB over FMDC(1.0) could be explained by electrostatic and π-π interactions. Finally, the facile recyclability of the FMDC(1.0) in MB adsorption was confirmed via successive adsorptions, FT-IR, and nitrogen adsorption; therefore, FMDC(1.0) can be suggested as a potential adsorbent to remove cationic dyes, especially with small molecular sizes.
从废水中去除有机染料对于我们安全的环境和健康的身体非常重要。在这项工作中，我们研究了用碳质材料去除阳离子染料（特别是小分子染料）的吸附去除方法，以开发一种具有竞争力的吸附技术。为了提高金属有机骨架（MOF）衍生碳（MDC）在染料吸附中的性能，我们用过硫酸铵溶液（APS）对一种 MOF（MAF-6）衍生的 MDC 进行了氧化功能化。虽然原始 MDC 的孔隙率通过氧化功能化而降低，但功能化 MDC（FMDC），特别是用 APS（1.0 M）处理 MDC 得到的 FMDC(1.0)，在吸附小阳离子染料（如亚甲蓝和 azure B）方面表现出显著的性能。例如，FMDC(1.0)对 MB 的最大吸附容量（Q）为 625.0 mg/g，这比任何用碳质材料报道的值都要大。此外，得到的 Q 值大约是用 Q 值为 160 mg/g 的活性炭和 Q 值为 298 mg/g 的 MDC 进行吸附的 Q 值的 4 倍和 2 倍。相反，用 MDC 进行氧化处理在吸附阴离子染料（如甲基橙）方面是不利的。此外，由于研究的吸附剂 FMDC(1.0)的孔径有限，功能化 MDC 对尺寸较大的阳离子染料（如亮绿、结晶紫、Janus 绿 B 和罗丹明 B）的吸附效果并不显著。FMDC(1.0)对 MB 的显著吸附可以用静电和π-π相互作用来解释。最后，通过连续吸附、FT-IR 和氮气吸附证实了 FMDC(1.0)在 MB 吸附中的可重复使用性；因此，FMDC(1.0)可以作为一种潜在的吸附剂来去除阳离子染料，特别是具有小分子量的阳离子染料。
