Carbon-Decorated Bismuth Ferrite Nanocomposite Stores Charge and Degrades Dye Under Visible Light

A bismuth ferrite nanocomposite decorated with activated carbon has shown strong performance in two roles at once: storing electrical charge as a supercapacitor electrode and breaking down methylene blue dye under visible light. The material, reported in the journal Ionics, was synthesized using the sol–gel technique, with varying amounts of activated carbon incorporated into bismuth ferrite (BFO) to study the effect of different carbon loadings.

Structural characterization confirmed the intended synthesis. High-resolution X-ray diffraction and Raman analysis verified the formation of the rhombohedral crystal structure and the successful incorporation of activated carbon into the BFO lattice. Crystallite sizes, calculated with the Scherrer equation, fell in the range of 21.65, 24.51, 29.94 and 35.04 nanometers across the studied compositions. Fourier-transform infrared spectroscopy identified distinct functional groups and vibrational modes, while field-emission scanning electron microscopy revealed particles that were spherical in shape and agglomerated in nature.

Further compositional checks supported the purity of the products. Energy-dispersive X-ray analysis and X-ray photoelectron spectroscopy indicated the formation of pure BFO and the BFO–activated carbon nanocomposite, with no other impurity peaks detected. These analyses together establish that the carbon was integrated into the ferrite structure rather than merely mixed alongside it.

The most consequential structural finding came from BET analysis, which revealed a mesoporous architecture in the BFO–AC nanocomposite with a specific surface area of 204.59 square meters per gram and pore sizes in the range of 2 to 18 nanometers. According to the study, this high surface area enhances electrochemical activity by providing more active sites for chemical reactions, improving charge storage capability, and it also supports dye adsorption during photocatalysis.

Electrochemical testing of the optimized BFO–AC nanocomposite electrode produced the study’s headline energy-storage figures. The electrode achieved a specific capacitance of 404.0 farads per gram at a discharge current of 1 ampere per gram. Long-term cycling tests showed the electrode retained 81.38 percent of its initial capacitance over 5000 continuous charge–discharge cycles, which the authors describe as indicating excellent electrochemical stability.

The photocatalytic results were equally prominent. Under visible-light illumination, the material demonstrated approximately 89.3 percent degradation of methylene blue, confirming high catalytic efficiency in the authors’ assessment. Methylene blue served as the model dye pollutant in these degradation experiments.

The authors frame the combined results as evidence that the optimized nanocomposite presents strong potential for practical energy storage and photocatalytic applications. The work demonstrates that adjusting the amount of activated carbon in the BFO matrix tunes both the structural properties and the functional performance of the resulting material.

As with any laboratory-scale study, the reported figures come from the controlled testing conditions described in the abstract, which does not include data on performance under variable real-world conditions or scaling to full devices. The published work presents the sol–gel synthesis route, the structural and surface characterization, and the measured electrochemical and photocatalytic performance of the optimized composition as its core evidence. The article was published in Ionics on 26 October 2026.

Subject of Research: Bismuth ferrite–activated carbon nanocomposites for electrochemical energy storage and photocatalytic dye degradation

Article Title: Activated carbon decorated BiFeO3 nanocomposites for high-efficiency electrochemical energy storage and photocatalytic dye degradation

Article References: Islam, M. U., Ansari, M. R., Paul, R., Peta, K. R., & Kossar, S. (2026). Activated carbon decorated BiFeO3 nanocomposites for high-efficiency electrochemical energy storage and photocatalytic dye degradation. Ionics. https://doi.org/10.1007/s11581-026-07613-w

Image Credits: AI Generated

DOI: 10.1007/s11581-026-07613-w

Keywords: bismuth ferrite, activated carbon, nanocomposite, sol–gel synthesis, supercapacitor, specific capacitance, photocatalysis, methylene blue, mesoporous, X-ray diffraction, BET surface area, Ionics