Application of the synergism between eggshells and copper in nanotechnology

Abstract

Eggshells, the non-edible part of an egg, have immense uses in nanotechnology. Copper being an inexpensive metal has versatile applications in nanotechnology. However, its susceptibility to oxidation limits its practical applications. Eggshells are an efficient candidate to synthesize cap copper nanoparticles and copper nanoclusters, which are used in various arenas (dye degradation, antibacterial activity, nitrophenol adsorption, copper adsorption, and sensing). Reports on the edible part of an egg for passivating copper nanoparticles are rare. Usually, chicken eggshells are mostly used in this regard. Moreover, eggshells can be used for the adsorption of ionic copper. Thus, the synergism between eggshells and copper is a very pivotal aspect. The use of biological waste in association with copper in various applications may open a new pathway towards the circular economy. This review article summarizes applications that evolved from copper-eggshell synergism.

Fig. 1. Structure of nanoscale metal materials. This figure has been adapted/reproduced from ref. with permission from Nanoscale Adv., copyright 2021.

Fig. 2. Structure of an egg. This figure has been adapted/reproduced from ref. with permission from Frontiers in Bioscience, copyright 2012, and from ref. with permission from Sustainable Food Technol., copyright 2024.

Fig. 3. Morphology of the ES/ESM of a fertilized and unfertilized egg. This figure has been adapted/reproduced from ref. with permission from Front. Bioeng. Biotechnol, copyright 2021.

Fig. 4. Mechanism for the formation of (a) AgNPs and (b) Ag₂O₂NPs/AgONPs involving proline. This figure has been adapted/reproduced from ref. with permission from the Journal of Bioresources and Bioproducts, copyright 2020.

Fig. 5. SEM images of the eggshell (a and b) as-crushed and calcined at: (c and d) 600 and (e and f) 900 °C. This figure has been adapted/reproduced from ref. with permission from RSC Adv., copyright 2019.

Fig. 6. Effect of the adsorption rates of differently treated eggshells with (A) reaction time, (B) Cu ion concentration, and (C) adsorbent dose. This figure has been adapted/reproduced from ref. with permission from Scientific Reports, copyright 2020.

Fig. 7. Dependence of (A) temperature and (B) pH on adsorption behavior. This figure has been adapted/reproduced from ref. with permission from Scientific Reports, copyright 2020.

Fig. 8. (a) Nyquist plots; (b) cyclic voltammetric response of GCE and Cu²⁺–Cu⁺/biochar/GCE without (a and b) and with (c and d) of 1 mM sodium nitrite in pH-7 phosphate buffer at 50 mV s⁻¹. This figure has been adapted/reproduced from ref. with permission from Science of the Total Environment, copyright 2020.

Fig. 9. Perspective view of the Cu(ii) adsorbed on the (001) HAp surface. This figure has been adapted/reproduced from ref. with permission from Environmental Nanotechnology, Monitoring & Management, copyright 2021.

Fig. 10. Elimination efficiencies with time of MO(aq) in the presence of CuCa HSD from calcined DES (a) and QES (b) and % COD elimination efficiency with time employing the CuCa HSD from calcined DES (c) and QES (d). This figure has been adapted/reproduced from ref. with permission from ACS Omega. Copyright 2023.

Fig. 11. (a) N₂ adsorption–desorption isotherms and (b) pore size distributions of different nanocomposites. This figure has been adapted/reproduced from ref. with permission from Chemical Engineering Journal, copyright 2019.

Fig. 12. (a) 4-NP reduction kinetics with ZC-EMS nanocomposites; (b) various catalysts for 4-NP reduction; (c) and (d) plots of C/C₀ and ln C/C₀vs. reaction time. This figure has been adapted/reproduced from ref. with permission from Chemical Engineering Journal, copyright 2021.

Fig. 13. Mechanism between copper and eggshells. This figure has been adapted/reproduced from ref. with permission from Molecular Catalysis, copyright 2021.

Fig. 14. Synergistic behaviour of eggshell–Cu for myriad applications.

Priyanka Sharma

Mainak Ganguly

Ankita Doi