Masters of Science (M.Sc.)

Thesis Group

Department of Applied Chemistry and Chemical Engineering

University of Rajshahi, Bangladesh

CGPA: 3.81 out of 4.00

Thesis title: “Synthesis and Characterization of Carbon Quantum Dots based nanocomposite and Its Application” 

Major Courses: Biomass Conversion Engineering, Physical Metallurgy, Polymer Technology, Medicinal Chemistry and Pharmaceutical Marketing, Pharmaceutical Technology and Management, Organic Pharmaceuticals and Nano Pharmaceutics, Process Design, Minerals Processing Engineering, Textile: Wet and Finishing, Food Science and Nutrition, Ceramic Engineering, and Pollution Control Engineering. 

Thesis title: “Synthesis and Characterization of Carbon Quantum Dots based nanocomposite and Its Application” 

Abstract

The removal of dye pollutants from aquatic environments has long been a challenge in the area of water management. Modern research has focused a great deal on the various treatment strategies for dye remediation from wastewater. In this awareness of industrial dye wastewater, carbon quantum dots (CQDs) and cobalt zinc ferrite (CZF) nanocomposites were synthesised for the making of carbon quantum dots coated cobalt zinc ferrite (CZF@CQDs) nanophotocatalysts. The photocatalysis process is one of the most efficient methods for heavy metal removal because of its simplicity and great effectiveness. The results of transmission electron microscopy (TEM), zeta potential value, and Fourier-transform infrared spectroscopy (FTIR) confirm highly dispersed 1-4 nm particles with the -45.7mV carboxylic functionalized surface of CQDs. The results of the synthesised CZF@CQDs photocatalyst showed an average particle size of ~15 nm according to TEM, scanning electron microscopy (SEM), and X-ray diffraction (XRD). The photocatalyst showed a 1.20 eV band gap, which followed the perfect visible light irradiation. TGA and DTA revealed the good thermal stability of the nanophotocatalyst. Vibrating-sample magnetometry (VSM) was carried out, and the saturation magnetisations for CZF and CZF@CQDs were 42.44 and 36.14 emu/g, respectively. A multipoint study determined the Brunauer-Emmett-Teller (BET) specific surface area of the CZF@CQDs photocatalyst to be 149.87 m2/g. Under visible light irradiation, the final CZF@CQDs nanophotocatalyst demonstrated remarkable efficiency (95% within 25 min) in the photocatalytic destruction of Reactive Blue 222 (RB 222) and Reactive Yellow 145 (RY 145) dyes, as well as mechanical stability and recyclability. Even after seven cycles of degradation, the nanophotocatalyst's efficiency (82 %, 7th cycle) was predominantly maintained. The effects of several parameters were also investigated, including initial dye concentration, nanophotocatalyst concentration, CQD content, initial pH of the dye solution, and reaction kinetics. Degradation study data follow the first-order reaction rate (R2 > 0.93). Finally, a simple and low-cost synthesis approach, rapid degradation, and outstanding stability of the CQD-coated CZF nanophotocatalyst should make it a potential photocatalyst for dye wastewater treatment.

Thesis Presentation