The controlled synthesis of g-C3N4/Cd-doped ZnO nanocomposites as potential photocatalysts for the disinfection and degradation of organic pollutants under visible light irradiation

Mudassar Sher; Mohsin Javed; Sammia Shahid; Shahid Iqbal; Muhammad Azam Qamar; Ali Bahadur; Muhammad Abdul Qayyum

doi:10.1039/d0ra08573a

The controlled synthesis of g-C₃N₄/Cd-doped ZnO nanocomposites as potential photocatalysts for the disinfection and degradation of organic pollutants under visible light irradiation

RSC Adv. 2021 Jan 7;11(4):2025-2039. doi: 10.1039/d0ra08573a. eCollection 2021 Jan 6.

Authors

Mudassar Sher¹, Mohsin Javed¹, Sammia Shahid¹, Shahid Iqbal², Muhammad Azam Qamar¹, Ali Bahadur³, Muhammad Abdul Qayyum⁴

Affiliations

¹ Department of Chemistry, School of Science, University of Management and Technology Lahore 54770 Pakistan mohsin.javed@umt.edu.pk.
² Department of Chemistry, School of Natural Sciences (SNS), National University of Science and Technology (NUST) H-12 Islamabad 46000 Pakistan shahidiqbal.chem@sns.nust.edu.pk.
³ Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University Seoul 08826 South Korea alibahadur138@snu.ac.kr.
⁴ Department of Chemistry, Division of Science and Technology, University of Education Lahore Pakistan Lahore Pakistan.

Abstract

The in situ growth of well-dispersed Cd-doped ZnO nanoparticles (Cd-ZnO NPs) on graphitic carbon nitride (g-C₃N₄) nanosheets was successfully achieved through the co-precipitation method for the formation of Cd-doped ZnO nanocomposites with g-C₃N₄ (Cd-ZnO/g-C₃N₄ NCs). The effect of different compositions of ternary nanocomposites (Cd-ZnO/g-C₃N₄ NCs) on photocatalytic properties was investigated. Ternary NCs, in which 60% g-C₃N₄ hybridized with 7% Cd-doped ZnO (g-C₃N₄/Cd-ZnO) NCs were proven to be optimum visible-light-driven (VLD) photocatalysts for the degradation of methylene blue (MB) dye. The enhanced photodegradation of MB is mainly due to the increase in the generation of photogenerated charge carriers (reactive oxygen species (ROS), O^2-, and ˙OH radicals). The electron spin resonance (ESR) experiment revealed that the superoxide and hydroxyl radicals were the leading species responsible for the degradation of MB. Moreover, the NC exhibited tremendous stability with a consistently high MB degradation rate for 10 successive catalytic cycles. The structural and optical properties of CdO, ZnO NPs, Cd-ZnO NPs, g-C₃N₄ NSs, and g-C₃N₄/Cd-ZnO NCs were investigated via XRD, SEM, EDX, TEM, FTIR spectroscopy, UV-Vis spectroscopy, ESR spectroscopy, and PL spectroscopy techniques. The synthesized photocatalysts were also applied against Gram-positive and Gram-negative bacterial strains to evaluate their antibacterial activities.