A photoluminescence study of nitrogen-doped carbon quantum dots/hydroxyapatite (NCQDs/HAp) nanocomposites

ABSTRACT

The objective of the present investigation is to functionalise nitrogen-doped carbon quantum dots (NCQDs) with hydroxyapatite (HAp) and study photoluminescence of the composites under ultraviolet radiation. NCQDs were prepared from microwave irradiation of 3:1 molar ratio of urea and citric acid mixture at 750 W for ~5 min. HAp was obtained via wet-chemical process from reacting 1 mol of calcium nitrate with 0.6 mol of ammonium dihydrogen phosphate at ~37°C for 15 h under basic pH (<8). NCQDs/HAp was synthesised from the hydrothermal method by mixing 5–15 mL aqueous solution of NCQDs with 1 g of HAp and autoclaving the mixtures at 100°C for 1 hour. The samples were characterised using diffraction, spectroscopic and microscopic techniques. Pure and nanoscale crystalline NCQDs/HAp composites, with an average particle size of 45 nm, were observed. The NCQDs/HAp resulted in higher photoluminescence than the HAp.

KEYWORDS:

• Nitrogen-doped carbon quantum dots (NCQDs)
• hydroxyapatite (HAp)
• nanocomposites
• photoluminescence
• biomaterials

Acknowledgments

The authors would like to thank the Department of Materials Science and the common instrumentation facility at the Central University of Tamil Nadu (CUTN) for providing the access to the necessary equipment during the project period.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

No external financial support was received for carrying out the current research project.