On the investigation of acid and surfactant modification of natural clay for photocatalytic water remediation

• Published in: Journal of materials science Vol. 53; no. 14; pp. 10095 - 10110
• Main Authors: Soni, Vineet Kumar, Roy, Toran, Dhara, Suman, Choudhary, Ganpat, Sharma, Pragati R., Sharma, Rakesh K.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.07.2018; Springer; Springer Nature B.V
• Subjects: Acids; Catalysis; Characterization and Evaluation of Materials; Chemical composition; Chemistry and Materials Science; Classical Mechanics; Clay; Clay minerals; Composites; Crystallography and Scattering Methods; Infrared analysis; Interlayers; Investigations; Materials Science; Micelles; Morphology; Organic acids; Organic chemistry; Polymer Sciences; Porosity; Solid Mechanics; Surface active agents; Surface area; Surfactants; Thermal stability; Eriochrome Black; Respective Critical Micelle Concentration; Surfactant Modification; Natural Clay; Clay Modification
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-018-2308-2

In this study, a series of mineral and organic acids are introduced to natural clay modification. Several analytical techniques are employed to identify the physical and chemical changes in clay. The effect of surfactants on these properties is also investigated. The samples are prepared using simple acid treatment without filtration. The alteration in surface morphology is proportional to the acid strength as evident from SEM and XRD analyses. Therefore, the treatment with mineral acid and organic acid/HNO 3 results in the formation of new layers by surface modification as depicted in SEM images, and a higher degree of suppression in characteristic XRD reflections of clay is noticed. However, the treatment with organic acids modifies the existing interlayer spacing of clay, and therefore, the XRD characteristic reflections of clay are less affected. These observations are also supported by FT-IR analysis. The surface area of modified clay is dependent on the acid strength, composition and size of counter-anion of acid. An increase in surface area and porosity is noticed after surfactant modification of HNO 3 -treated clay, where the change is more prominent at the concentration higher than their respective critical micelle concentration. Thermal stability is dependent on the chemical composition and surface area of clay materials. A relatively higher absorbance is observed for modified clay materials compared with untreated clay during DRS analysis. The catalytic efficiency of modified clay materials in Eriochrome Black T degradation has been demonstrated.