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

Facile preparation of g-C₃N₄/ZnO S-scheme heterojunction for photocatalysis: insights from the DFT studies and radical scavenging experiments

C. P. Prathibha, Srinivas Mallapur, Sumanjali Kota, B. M. Rajesh, Sumit B. Bubanale, Sanjeev P. Maradur, R. Shyamala, and S. Girish Kumar

Department of Chemistry and Centre for Nano and Functional Materials, REVA University, Bengaluru, India

E-mail: srinivas.m@reva.edu.in

Received: 28 April 2025  Accepted: 7 August 2025

Abstract:

Heterojunctions comprising wide and narrow gap materials with distinct band edge potentials always remain an ideal choice to operate under wide spectrum of solar light for the photocatalytic reactions. In this context, integrating ZnO and g-C₃N₄ gains prominent interest from the prospect of easy preparation and suitable band edge positions to form the heterojunctions. In the current work, the ZnO/g-C₃N₄ is obtained by annealing the pre-crystallized materials (550 °C) and characterized by using various analytical techniques. The X-ray diffraction results confirmed the composite formation, while the optical response measurements revealed the light absorption ability in the visible region. The ZnO/g-C₃N₄ enabled the faster degradation of indigo carmine dye compared to individual phase counterparts under the light illuminated conditions. This was attributed to the formation of S-scheme heterojunction which allowed energetic charge carriers to participate in the reactions and was later supported with radical scavenging experiments. Furthermore, the density functional theory calculations indicated the formation of interfacial bonds such as Zn–N and Zn–C which played a vital role in boosting the charge carrier separation process.

Keywords: g-C3N4; ZnO; Heterojunction; Interfacial bonds; Photocatalysis; Environmental remediation

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04337-5

Chemical Papers 79 (12) 8595–8604 (2025)