Enhanced photocatalytic degradation of rhodamine B by bismuth-based three-layered nanomaterials co-doped with indium and tantalum under UV irradiation

Abstract

We have enhanced the photocatalytic activity of pure BTO surfaces through the introduction of tantalum and indium oxides. These dopants facilitate the decomposition of Rhodamine B, an organic pollutant. The compound Bi4Ti2.92 (Ta0.5, In0.5)0.08O12, also known as 8% (Ta/In)-BTO, was successfully produced through the molten salt synthesis technique. It is characterized as a three-layer Aurivillius phase with the mentioned chemical composition. The XRD analysis showed that tantalum and indium dopant ions had been successfully integrated into the perovskite B-site of the Aurivillius structure, as indicated by the orthorhombic crystal structure with B2ab space group. The refinement was analyzed using Rietveld method with the FullProof software program. The scanning electron microscope was utilized to examine the microstructure and morphology of 8% (Ta/In)-BTO sample. The results revealed an average grain size of 2.408 µm and an average thickness size of 0.325 µm. The FTIR analysis revealed the presence of Ti–O and Bi–O bands, and it was observed that 8% (Ta/In)-BTO possesses a greater surface area, resulting in enhanced photocatalytic performance. The Tauc method was employed to analyze the UV–vis absorbance spectra, resulting in the determination of band gap energy of 3.2 eV. This value closely aligns with the bandgap values typically observed in orthorhombically distorted materials. According to the BET analysis, the sample exhibited type VI isotherms, indicating a mesoporous structure with specific surface area and pore distribution values of 40.87 m2/g and 4.7 nm. This configuration led to excellent photocatalytic performance. Furthermore, the results related to the degradation of Rhodamine B (RhB) under UV light irradiation displayed a 98% performance (180 min), providing a convincing illustration of the material's potential for long-lasting and effective photocatalytic use.