Design of chitosan nanocomposite hydrogel for sensitive detection and removal of organic pollutants

In this project, cerium oxide-cobalt oxide (CeO₂-Co₂O₃) nanocomposite-based material have been simply synthesized and intercalated to chitosan (CH) hydrogel to prepare CH/CeO₂-Co₂O₃ nanocomposite hydrogel. CH/CeO₂-Co₂O₃ nanocomposite was applied to nitrophenols reduction where it displayed perfect catalytic activity for 4-nitrophenol as compared to 2-nitrophenol and 2,6-dinitrophenol. Various factors were tested for optimization of catalytic removal approach. Farther, CH/CeO₂-Co₂O₃ nanocomposite catalyst was coated on cotton cloth (CC) as support, which provided high catalytic performance even after reusing three times. CeO₂-Co₂O₃ nanocomposites was also employed as electrochemical sensor where CeO₂-Co₂O₃ was coated on pencil-graphite lead electrode (PGLE) and glassy carbon electrode (GCE) and used as working electrodes to detect different nitrophenols electrochemically via cyclic voltammetry. CeO₂-Co₂O₃ was more selective toward 4-nitrophenol and the reduction peak of 4-nitrophenol was much more enhanced with increase in concentration ranging from 11.80 to 48.75 μM. The detection limit was found to be 0.46 μM (S/N = 5). Thus, the prepared materials were selective for detection and removal of 4-nitrophenol. Various factors were tested to optimize best conditions for developed nanocomposite materials in electrochemical sensing and catalytic removal approaches. Thus, it is expected that the designed nanocomposite will be able to employ as promising material for providing clean water.