The increase in the environmental pollution witnesses globally today has become a threat to humanity and the ecosystem at large. As a result, a lot of concerns have been raised as far as environmental protection and conservation is concerned. Water pollution, for example, leads to carcinogenic effects, therefore, affecting the aquatic life. Dye effluents have been considered as the main contributor towards water pollution. To minimize its effects, various treatments techniques have been developed. They include biological degradation, chemical oxidation, and adsorption among others. However, adsorption is seen by most of the industrialists and researchers as the best method for the organic dye removal. It is much, more efficient, stable, simple to handle and also does not lead to secondary pollution when used.
MgO based composites can be used to enhance the sorption capacity for the dye removal. Although there are various approaches for composites synthesis, carbon-based hierarchical structure approach is preferred due to its unique chemical and physical properties. The nanoparticles are made more stable through dispersion in sandwiched carbon sheets hence leading to sandwich-like nanocomposite. Hence, sandwiched-like nanocomposite is expected to enhance the sorption capacity of dye removal.
A group of researchers at Neijiang Normal University, College of Chemistry and Chemical Engineering in China: Dr. Xiaogang Zheng, Ming Huang, Dr. Yaohui You, Dr. Xiaojing Fu and Professor Yong Liu in collaboration with Professor Jing Wen from Qinghai Institute of Salts Lakes in China devised an organic dye removal technique through one-pot synthesis of sandwich-like [email protected] nanocomposites using a one-pot hydrothermal route. This was in a bid to enhance the adsorption performance of the nanocomposites for efficient removal of the organic dyes. They further investigated the adsorption behaviors of the as-obtained samples and the effects of the other factors such as pH value, inorganic ions among others on the sorption capacity of the [email protected] Their research work is published in the research journal, Chemical Engineering Journal.
From the experimental results obtained, the authors observed a high sorption capacity for methyl orange in the as-obtained sandwiched-like [email protected] as compared to the carbon bulk and MgO nanoparticles methods. Furthermore, increase in the pore volume and specific area led to an increase in the sorption capacity. Also, [email protected] reached the maximum sorption capacity at a carbon thickness of 5nm.
According to the authors, sandwiched-like [email protected] exhibit high sorption capacity because of the increase in the electrostatic interaction experienced between the positively charged sandwiched-like [email protected] nanocomposites and the anionic dye molecules. Furthermore, the efficiency of the as-obtained sandwich-like samples was confirmed by the Langmuir isotherm and the pseudo-second-order models. For instance, the kinetic adsorption behaviors of the sample investigated fitted well with the pseudo-second-order model while on the other hand, the authors confirmed that the one-pot synthesized [email protected] system was indeed mono-layered adsorption by using the Langmuir isotherm model. Additionally, sorption process of the methyl orange was an endothermic process which was controlled by the intraparticle diffusion and the external mass transfer.
Zheng, X., Huang, M., You, Y., Fu, X., Liu, Y., & Wen, J. (2018). One-pot synthesis of sandwich-like [email protected] with enhanced sorption capacity of organic dye. Chemical Engineering Journal, 334, 1399-1409.Go To Chemical Engineering Journal