Synthesis and optimization of barium manganate nanofibers by electrospinning

doi:10.1016/j.ceramint.2011.09.026

Ceramics International

Volume 38, Issue 2, March 2012, Pages 1441-1445

https://doi.org/10.1016/j.ceramint.2011.09.026 Get rights and content

Abstract

Barium manganate nanofibers were successfully synthesized for the first time after heat treatment of composite nanofibers of polyvinyl pyrrolidone (PVP), barium acetate and manganese acetate using electrospinning technique. Different PVP concentrations were used and the results show that PVP concentration had played important role in the formation, uniformity, homogeneity and particularly in the reduction of nanofibers diameter. Crystal structure, microstructure, elemental analysis and surface morphology were studied using X-ray diffraction analysis, scanning electron microscopy, energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. X-ray diffraction results show that at low temperature there is no crystallinity in the fibers sample and at ∼400 °C formations of barium manganate crystalline phase starts and finally at 700 °C all the nanofibers became single phase. The first two high intensity peaks (1 0 1) and (1 1 0) give an average crystallite size of about 20 nm. The scanning electron micrographs show that the morphology of the fibers is smooth and uniform at low temperature and become slightly porous at intermediate temperature and finally at high temperature of 700 °C the fibers become highly porous, shrank and their average diameter reduced from ∼400 nm to about 100 nm. These fibers are made of grains with sizes ranging from 15 to 30 nm. Energy dispersive X-ray spectroscopy and Fourier transform infra-red results are also in good agreement with XRD and SEM results.

Introduction

Ceramic materials have high corrosive resistance and high chemical erosion which makes them useful in many fields of technology [1]. In recent years, one-dimensional ceramic materials such as nanorods, nanotubes, nanowhiskers, and nanofibers, etc., have attracted great interest because of their superior electrical, magnetic, optical, thermal, gas sensing and catalytic properties that arise from the difference in surface morphology and size effect as compared to their bulk counterparts [2]. Among these nanostructures, nanofibers have many potential applications owing to their high porous structure, low density and high surface to volume ratio [3], [4]. Electrospinning is one of the simplest, versatile, time and cost effective technique used for the synthesis of ultrafine, continuous and uniform diameter nanofibers of polymers, composites and ceramics [5], [6]. An important feature of this technique is that the electrospun nanofibers mats are suggested for membrane-based applications in environmental science, catalysis, and energy technology [1]. Shao et al. [7] have reported for first time the formation of ceramic nanofibers by electrospinning technique in 2002. The technique has been used successfully by many research groups for the synthesis of varieties of ultrafine ceramic nanofibers, e.g., BaTiO₃, LaMnO₃, LaFeO₃, ZnFe₂O₄, Pb(Zr_0.5Ti_0.5)O₃, etc., [5], [8], [9], [10], [11].

To the best of our knowledge synthesis of BaMnO₃ nanofibers has not been reported. In this paper, we report the successful synthesis of continuous, porous, and uniform diameter nanofibers of BaMnO₃ with the effect of temperature and PVP concentration using electrospinning technique.

Section snippets

Experimental

Barium acetate and manganese acetate were used as the starting materials for the synthesis of BaMnO₃ nanofibers. We dissolved 1.2772 g of Ba(CH₃COO)₂ and 1.2254 g of Mn(CH₃COO)₂·4H₂O in 6 ml acetic acid and stirred for 10–15 min. Polyvinyl pyrrolidone (PVP, M_w ≈ 1,300,000) of 0.1, 0.5, 1.0, 1.5 and 2.0 g each was dissolved in 13.5 ml ethanol and stirred for 10–15 min. After stirring, both solutions were mixed and the final mixture was thoroughly stirred at room temperature for 16 h to get a homogeneous

XRD analysis

The XRD patterns of barium manganate nanofibers after annealing at 100, 400 and 700 °C were shown in Fig. 1(a), (b) and (c), respectively. Fig. 1(d) shows the standard XRD pattern of single phase 2H-BaMnO₃, JCPDS card no. 26-0168. In Fig. 1(a) the XRD pattern is amorphous type which means that barium manganate phase is not formed at 100 °C. However, at 400 °C the high intensity peaks of BaMnO₃ crystalline phase appeared and became more prominent and clear at 700 °C without any impurity peak which

Conclusions

Barium manganate porous nanofibers of diameter about 100 nm were successfully synthesized from the heat treatment of PVP/Ba(CH₃COO)₂/Mn(CH₃COO)₂ composite nanofibers using electrospinning technique. Results show that PVP concentration had played an important role in the formation, uniformity, homogeneity and particularly in the reduction of diameter of nanofibers when other parameters were kept constant. The effect of temperature on crystal structure and morphology of nanofibers was also studied

Acknowledgments

The authors highly acknowledge the financial support from the Higher Education Commission (HEC), Pakistan.

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Synthesis and optimization of barium manganate nanofibers by electrospinning

Abstract

Introduction

Section snippets

Experimental

XRD analysis

Conclusions

Acknowledgments

Sensors and Actuators B: Chemical

Materials Letters

Materials Research Bulletin

Materials Letters

Solid State Communications

Ceramic nanofibers fabricated by electrospinning and their applications in catalysis-environmental science and energy technology

Polymers Advanced Technologies