Exploring the optical limiting, photocatalytic and antibacterial properties of the BiFeO3-NaNbO3 nanocomposite system.

Rehana P Ummer,Sabu Thomas,Pramod Gopinath,Sreekanth Perumbilavil,Jiya Jose,Nandakumar Kalarikkal

doi:10.1039/d0ra09776d

Abstract

Thin films of BiFeO3–NaNbO3 composites were fabricated in a PMMA matrix. XRD and HRTEM were used for structural investigations. The grain size and surface morphology of samples were analysed through HRTEM images. The self-cleaning property of any material accelerates its industrial applications. Hence, along with the optical limiting performance, the photocatalytic and antibacterial activity of BiFeO3–NaNbO3 composite samples were also studied. BiFeO3–NaNbO3 films fabricated in the PMMA matrix exhibit strong optical nonlinearity when excited by 5 ns laser pulses at 532 nm. The origin and magnitude of the observed optical nonlinearity were explained on the basis of the weak absorption saturation and strong excited state absorption. The photocatalytic performance of samples was analysed by dye degradation method using Methyl Orange dye. The dye degradation rate in the presence of the catalyst is heeded in a particular time interval, which exhibits the photocatalytic performance of the samples. The destruction of microbial organisms that are in contact with the material was contemplated, which could prove its antibacterial activity. The effect of the particle size on the photocatalytic activity was also investigated.

Highlights

The results indicate that the catalyst could exalt the rate of degradation, as the degradation efficiencies of the dyes are higher with the presence of the catalyst in the given time
The particle size was found to have an impact on the photocatalytic activity of the material
The enhanced photocatalytic activity of the samples could be attributed to the nano size of the material

Summary

Introduction

The BiFeO3–NaNbO3 composite material is a well known multiferroic, which has found wide applications in storage devices and sensors, among others.[1,2,3,4,5,6,7,8,9,10] The energy storing and optical limiting property of this material has been examined previously.[12,13] In our previous article, we have scrutinized the electric, magnetic, and optical limiting properties of the BiFeO3– NaNbO3 composite in its powdered form[12] and thin lm in a PVDF-TrFE matrix.[13]. Clinically nontoxic,[37] and reports show that they are active against bacteria, such as E. coli and H. pylori.[28] The photocatalytic and antibacterial activity of semiconductor nanomaterials were found to be excellent.[12,13,27] Various organic pollutants can be degraded completely through photocatalysis using metal oxide semiconductor nanostructures under UV light irradiation.[30,36,39] They have been used widely in many investigations because of their application for the destruction of chemical contaminants and water splitting Conventional semiconductor photocatalysts, such as TiO2 and ZnO, are costeffective, non-toxic, and serve as antimicrobial agents.[50,51,52] As they have a wide band gap (3.2 eV), they are UV absorbers and consist only 4% solar light irradiation, which is one of their practical application hindrances.[27,30,31,32] research on developing a metal oxide nanoparticle with a narrow band gap is of current interest.[30,31,32]. Activity of the powder samples was assessed using the well diffusion method

Results and discussion

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Conclusion