On the investigation of acid and surfactant modification of natural clay for photocatalytic water remediation
- 23 Downloads
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/HNO3 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 HNO3-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.
The authors acknowledge the DBT-PAN IIT center for bioenergy (BT/EB/PANIIT/2012) for financial assistance.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- 1.Bergaya F, Theng BKG, Lagaly G (eds) (2013) Developments in clay science, handbook of clay science. Elsevier, AmsterdamGoogle Scholar
- 2.Yuan P, Thill A, Bergaya F (eds) (2016) Developments in clay science, nanosized tubular clay minerals. Elsevier, AmsterdamGoogle Scholar
- 16.Siddiqui MHK (1968) Bleaching earths. Pergamon Press, LondonGoogle Scholar
- 27.Pinnavaia TJ, Beall GW (2001) Polymer-clay nanocomposites. Wiley, BerlinGoogle Scholar
- 28.Theng BKG (2012) Developments in clay science, formation and properties of clay-polymer complexes. Elsevier, AmsterdamGoogle Scholar
- 42.Murray HH (2007) Applied clay mineralogy. Occurrences, processing and application of kaolins, bentonites, palygorskite-sepiolite, and common clays. Elsevier, AmsterdamGoogle Scholar
- 51.Timofeevaa MN, Panchenkoa VN, Volcho KP, Zakusine SV, Krupskaya VV, Gil A, Mikhalchenko OS, Vicente MA (2016) Effect of acid modification of kaolin and metakaolin on Brønsted acidity and catalytic properties in the synthesis of octahydro-2H-chromen-4-ol from vanillin and isopulegol. J Mol Catal A: Chem 414:160–166CrossRefGoogle Scholar
- 55.Connolly GC (1943) Catalyst. US Patent 2330685Google Scholar
- 57.Siddiqui MKH (1968) Bleaching earths, 1st edn. Pergamon Press, LondonGoogle Scholar