NS-CQDs/TiO2 hybrid nanocomposites incorporated with nutshell derived NS-CQDs as photocatalyst for environmental/biological applications and cytotoxicity effect

Koç Keşir M., AYAZOĞLU DEMİR E., Yılmaz M. D.

Journal of Environmental Chemical Engineering, vol.13, no.2, 2025 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 13 Issue: 2
  • Publication Date: 2025
  • Doi Number: 10.1016/j.jece.2025.116001
  • Journal Name: Journal of Environmental Chemical Engineering
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, CAB Abstracts, Chemical Abstracts Core, Compendex, INSPEC, Veterinary Science Database
  • Keywords: Cytotoxicity, wet impregnation method, E. coli / A. niger, Fix-bed pyrolysis reactor, Methylene blue (MB) / Cr (VI), Nutshell carbon quantum dot, TiO2 nanorods
  • Karadeniz Technical University Affiliated: Yes

Abstract

Being a class of carbon nanoparticles, carbon quantum dots (CQDs) have been used as a precursor in modification of semiconductor photocatalysts. The efficient utilization of natural resources ‘‘biomass’’ for the synthesis of CQDs which are important for reducing environmental pollution, and also creates a field of application area such as water treatment. In this work, fix-bed pyrolysis reactor was used to synthesis the bright fluorescence NS-CQDs using nutshell (NS) without any chemicals. One-dimensional TiO2 nanorods (TNRs) fabricated via hydrothermal route was decorated with low-cost and eco-friendly (NS-CQDs) by wet impregnation method to produce hybrid NS-CQDs/TNRs nanocomposite. Various characterization techniques such as TGA, XRD, XPS, FE-SEM/EDS, HRTEM, FTIR, fluorescence and UV–vis spectroscopy have been employed to confirm the structural and optical properties. The photocatalytic activity of as-prepared NS-CQDs/TNRs were investigated for methylene blue (MB), hexavalent chromium Cr (VI), Escherichia coli (E. coli) and Aspergillus niger (A. niger) under UV-A. Subsequently, MTT assay was carried out using ARPE-19 (Epithelium) and MCF-7 (Breast Cancer) cell lines as the model system so as to designate whether produced NS-CQDs and hybrid NS-CQDs/TNRs composite was cytotoxic or not. The obtained results suggest that the photocatalytic activity of NS-CQDs/TNRs composites was slightly enhanced as compared to that of TNRs while not only NS-CQDs but also NS-CQDs/TNRs composites show no significant change in terms of cytotoxicity.