Synthesis and characterization of cerium bismuth oxide nanocomposite: Enhanced photocatalytic degradation of crystal violet dye

Key findings from this study

This research indicates that:

• The CBO (1:1) nanocomposite achieved the lowest bandgap energy of 2.4 eV and smallest crystallite size of 19 nm among composite formulations.
• Cerium bismuth oxide nanocomposites demonstrated superior photocatalytic activity under sunlight compared to individual Bi2O3 and CeO2 components.
• Composite formation reduced bandgap values substantially below both parent oxides, with CBO (1:1) showing particularly favorable optical properties for light-driven catalysis.

Overview

The study synthesized cerium bismuth oxide (CBO) nanocomposites via precipitation methodology and evaluated their photocatalytic performance in degrading crystal violet dye under sunlight. Bismuth and cerium oxides, alone and combined, were characterized through X-ray diffraction, UV-visible spectroscopy, infrared spectroscopy, and electron microscopy. The nanocomposite formulations demonstrated enhanced photocatalytic activity compared to single-component materials.

Methods and approach

Cerium bismuth oxide nanoparticles were synthesized using chemical precipitation. Structural characterization employed powder X-ray diffraction analysis. Optical properties were assessed via UV-visible spectroscopy with Kubelka-Munk plots determining bandgap values. Fourier transform infrared spectroscopy identified functional groups. Scanning electron microscopy visualized surface morphology. Photocatalytic testing occurred under natural sunlight with total organic carbon removal measurements validating degradation efficiency.

Results

X-ray diffraction revealed crystallite sizes of 43 nm for Bi2O3, 23 nm for CeO2, 19 nm for CBO (1:1 ratio), and 27 nm for CBO (2:1 ratio). Bandgap analysis using Kubelka-Munk plots established values of 2.9 eV for Bi2O3, 3.2 eV for CeO2, 2.4 eV for CBO (1:1), and 2.6 eV for CBO (2:1). The CBO (1:1) nanocomposite exhibited the lowest crystallite size among composite formulations, correlating with reduced bandgap energy.

Photocatalytic testing under sunlight demonstrated significantly higher degradation activity for the nanocomposite materials relative to individual oxide components. Total organic carbon removal data confirmed the enhanced photocatalytic efficiency of the composite formulations, validating the synergistic effect of combining cerium and bismuth oxides.

Implications

The reduced bandgap energies observed in CBO nanocomposites compared to single-component oxides suggest improved light absorption capacity across the visible spectrum. This enhancement enables more efficient photocatalytic degradation pathways for organic pollutants in aqueous systems. The bifunctional nature of cerium and bismuth oxides demonstrates potential for practical applications in water remediation and dye removal technologies operating under ambient solar irradiation.

The composition-dependent crystallite size variations influence the surface area available for photocatalytic reactions. Optimization of the cerium-to-bismuth ratio enables tuning of both structural and optical properties, providing a design strategy for enhancing catalytic performance. These findings suggest that nanocomposite approaches combining multiple metal oxides merit further investigation for large-scale environmental remediation applications.

Scope and limitations

This summary is based on the study abstract and available metadata. It does not include a full analysis of the complete paper, supplementary materials, or underlying datasets unless explicitly stated. Findings should be interpreted in the context of the original publication.