Removal of rhodamine B from aqueous solution using SrCo_xBi₄Ti_4-xO₁₅ aurivillius phase ceramics

Abstract

The contamination of aquatic environments by colored and toxic dyes such as rhodamine-B causes many problems for the human health. Their high stability is a major problem for the removal of dyes. The adsorption technique can be used for the treatment of dyes efficiently. In this study, SrCo_xBi₄Ti_4-xO₁₅ nanostructures with different cobalt ions ratios (x = 0.0, 0.01, 0.03 and 0.05) are synthesized and characterized by XRD, XRF, FT-IR, Uv-vis, Uv-DRS, PL and TEM measurements. Ethanolamine is used as a precipitating agent. All samples crystallized in an orthorhombic crystalline system according to the XRD patterns and have layered morphology as determined by the TEM analysis. Compared with SrBi₄Ti₄O₁₅, samples doped with cobalt (II) ions show a shift toward lower angles in their XRD patterns, a shift toward lower wavelength side, and higher bond gap energy. In addition, the luminescence intensity is decreased with the increase in the Co²⁺ concentration. The adsorption capacity of SrCo_xBi₄Ti_4-xO₁₅ nanostructures on the removal of rhodamine B (RB) from the aqueous medium was investigated under ambient temperature. The effective parameters on the adsorption such as catalyst dosage, dye concentration, pH and time are optimized. In comparison with the pure SrBi₄Ti₄O₁₅, compounds doped with Co²⁺ have better adsorption capacity for RB.

Keywords:

• SrCoxBi₄Ti₄-xO₁₅ nanostructures
• cobalt doped SrBi₄Ti₄O₁₅
• adsorption
• rhodamine B (RB)
• XRD measurement
• Kinetic and isotherm investigations

Acknowledgment

The authors acknowledge the financial support of the Iran National Science Foundation; INSF (97013839).