ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Variant solvothermal synthesis of N-GQD for colour tuning emissions and naked eye reversible shade tweaking pH sensing ability

S. Saisree, J. S. Arya Nair, and K. Y. Sandhya

Department of Chemistry, Indian Institute of Space Science and Technology Valiyamala, Thiruvananthapuram, India

E-mail: sandhya@iist.ac.in

Received: 26 April 2022  Accepted: 14 July 2022

Abstract:

In the present work, nitrogen-doped graphene quantum dots (N-GQD) with tailored colour emissions were synthesized through a solvothermal route using different solvents: N-Methyl-2-pyrrolidone (NMP), water (H₂O) and dimethylformamide (DMF), and polyaniline (PANI) as the precursor material. The N-GQD exhibited a noticeable red-shifted emission from blue to yellow with varying solvents from NMP, H₂O, and DMF. The N-GQD/NMP is blue emissive, whereas N-GQD/H₂O and N-GQD/DMF are green and yellow emissive. The N-GQD/DMF and N-GQD/NMP exhibited a naked eye detectable reversible colour tweaking property with varying pH. The N-GQD/NMP changed from light green to violet; the N-GQD/DMF changed from pink to light brown when the pH was adjusted from 1 to 11.

Keywords: Nitrogen-doped graphene quantum dots; pH sensing; Colour tweaking; Red-shifted emission

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02376-w

Chemical Papers 76 (11) 6953–6962 (2022)