SYNTHESIS OF TERNARY LAYERED DOUBLE HYDROXIDES AND THEIR COMPOSITES FOR ENVIRONMENTAL APPLICATIONS

Abstract

The thesis focuses on the synthesis of layered double hydroxides (LDH) and their composite materials under ambient conditions, with emphasis on environmental applications. The structure, morphology, thermal stability, optical and catalytic behaviour of the synthesized LDHs were studied using various instrumentation techniques. Further, the synthesized lattice was utilized for the elimination of toxic effluents i.e. nitroarene compounds (NACs) and anionic azo dyes from wastewater. In addition, ZnCuNi-LDO and ZnCuCe-LDO were used as photocatalysts for the degradation of Ciprofloxacin (CIF) drug and cationic/anionic azo dyes. Afterwards, a smartphone-based approach was opted for the determination of dye concentration. The results obtained were in agreement with those obtained from UV-Vis spectrophotometer. Upon the successful formation of layered structure, the structure regaining capability i.e. memory effect and anion exchange properties were investigated. The PXRD and FTIR results confirmed the structure regaining ability of the lattice i.e. memory effect as well as the exchange of anion in the interlayer region. Moreover, the synthesis of carbon nitride-based composite materials was also carried out with synthesized LDHs, and were later used for the degradation of p- NP and Congo Red (CR). Subsequently, the magnetically separable Fe3O4/SiO2/ZnCuNi- LDH composite was synthesized using electrostatic self-assembly method. The composite was utilized for the catalytic hydrogenation of p-NP and reduction of cationic dye Rhodamine B (RhB).