Synthesis of Magnetic Cryptomelane-type

manganese oxide (OMS-2) nanotubes for the

removal of lead based compounds from water

samples

Submitted to

Amity Institute of Nanotechnology

Amity University, Noida

In partial fulfillment of the requirements for the degree of

B.TECH+M.TECH NANOTECHNOLOGY

By: Shubham Raina

ENROLLMENT NO.: A1223313003

Under the guidance of

Dr. Ranjit Kumar

AMITY INSTITUTE OF NANOTECHNOLOGY

PROJECT REPORT-2015

PROJECT TITLE : Synthesis of Magnetic Cryptomelane-type manganese oxide (OMS-2) nanotubes for the removal of lead based compounds from water

samples

PROGRAMME : B.tech + M.tech Nanotechnology

SEMESTER : 5

NAME of STUDENT : Shubham Raina

ENROLLMENT NO : A1223313003

BATCH : 2013-2018

DURATION : 30 days

NAME OF GUIDE : Dr. Ranjit Kumar

Internal Guide Student

DECLARATION BY THE CANDIADTE

I hereby declare that the matter in the project report entitled “Synthesis of Magnetic Cryptomelane-type manganese oxide (OMS-2) nanotubes for the removal of lead based compounds from water samples ” submitted to Dr. Ranjit Kumar , Assistant Professor, Amity Institute of Nanotechnology, Amity University, and Noida is a bonafide and genuine research project under the guidance of Dr. Ranjit Kumar. The work done in the report is original and has not been submitted earlier for the award of any degree, diploma, or fellowship of any other university or institution.

Date: July 15, 2015

NAME : Shubham Raina

Enrolment no. : A1223313003

CERTIFICATE BY THE GUIDE

This is to certify that the report entitled “Synthesis of Magnetic Cryptomelane-type manganese oxide (OMS-2) nanotubes for the removal of lead based compounds from water samples ” is a bonafide research work carried out by Shubham Raina, which is submitted in partial fulfillment for the award of the degree of “B.tech + M.tech Nanotechnology” in the Amity University, Noida .

Date: Prof. Dr. Ranjit Kumar

Place: Noida, Uttar Pradesh

ACKNOWLEDGEMENT

I would like to thank Dr. Ranjit Kumar for giving me such

interesting and challenging topic to carry out my experimental

research project .

I would also like to thank sir for helping me , guiding me by

providing relevant and important concepts and other important

data regarding my experimental work .

Table of contents

S.No. Topic Page no.

1. ABSTRACT PAGE 8

2. INTRODUCTION Page 8

3. EXPERIMENTAL PROTOCOL

Page 9

4. SAMPLE CHARACTERIZATION

Page 10

5.

RESULTS AND

DISCUSSION

Page 11

6. FUTURE WORK Page 12

7.. CONCLUSION Page 12

8. REFERENCES Page 13

Abstract

Magnetic cryptomelane-type manganese oxide nanotubes were successfully prepared by depositing Iron(II) oxide (magnetite/ Fe3O4) nanoparticles onto the nanotubes. The synthesized material exhibits excellent magnetic and catalytic properties for the degradation of lead based compounds from water samples and can be magnetically separated from the solution with ease leaving clear water behind .

Introduction

Manganese oxide is a type of microporous transition metal oxide that can formmixed-valent semiconducting octahedral molecular sieves (OMS) with tunnel likestructures of various sizes [2]. OMS materials have extensive applications and advantages such as low cost, high adsorption activity, and non-toxicity [3–10]. Among these, α-MnO2 (cryptomelane, OMS-2), having an ordered tunnel structure shared with MnO6 octahedral chains, has been extensively used as a cathode material [11],adsorbents [8,13], and catalysts [14–17].OMS-2 nanotubes can be easily prepared by hydrothermal treatment of KMnO4 in the HCl solution [5, 8, 17] and has been recently revealed to possess high adsorption capability for dye degradation and heavy metal ion removal in wastewaters [13, 16].In most research reports it remains a challenge to develop a simplistic and economic rout to separation or recovery of these nano- materials from heterogeneous systems. To solve this problem magnetic separation is being considered an ideal alternative to the removal of in situ nanomaterials via magnetic induction [13]. In this report the successful synthesis of ferromagnetic cryptomelane-type nanotubes have been carried out by a combination of hydrothermal and precipitation techniques, and the prepared Fe3O4-OMS-2 nanotube composite exhibited excellent adsorption efficiency for the degradation of lead based compounds from water samples .

Experimental Protocol

Preparation of OMS-2 Nanotubes

To synthesize MnO2 nanotubes, a hydrothermal method was carried out [17]. 0.9 g of KMnO4 and 2.0 mL of HCl (37 wt%) were added to 40 mL of deionized water under magnetic stirring to form the precursor solution.After stirring the solution for about 20 min, it was transferred into an autoclave with a capacity of 100 mL. The autoclave was sealed and heated in an oven at 110 °C for 24 hrs . The product was filtered, washed with distilled water and ethanol, dried at 80 °C.Preparation of Fe3O4/OMS-2 Nanotubes

To fabricate the magnetic manganese oxide nanotubes, nanoparticles of Fe3O4 weredeposited onto OMS-2 nanotubes using a chemical co-precipitation method [13]. 0.1 M urea extract was added to an equimolar solution of ferric chloride (FeCl3) . The resulting solution was left for stirring for 2 hours at 85-90°C . 0.1 M solution of ferrous sulphate heptahydrate (FeSo4.7H2O) was added to the solution with continuous stirring for 10-15 minutes. For the formation of magnetic Fe3O4 pH of the solution was increased to maximum by addition of 0.3 M NaOH solution with continuous stirring. After 20 minutes of continuous stirring , 0.5g of the OMS-2 precursor (powder) was added to the solution. The final solution so obtained was sonicated for 15 minutes. The solution was then left for overnight aging. The product was then washed several times with distilled water till pH became neutral ( before being separated using a magnet – for magnetic separation test ). The product was then dried in an oven at 80°C for 1 hour in a petridish. The dried product was scraped of with the help of a spatula , ground into a fine powder using a pestle and mortar and stored in a cellophane pouch .

Adsorption Property Measurement

The reaction was carried out in 3 boiling tubes , which contained varying concentrations of lead acetate solution (0.1 M ,0.01 M ,0.05 M) prepared by dissolving appropriate quantity of lead acetated powder (analytical reagent) in distilled water, and 100 mg of composite . The mixture was allowed to react at

room temperature with continuous stirring. The solutions were kept on stirring for about 20 minutes and then left undisturbed .After about 30-60 minutes of keeping the boiling tubes undisturbed , it was observed that that the composite completely adsorbs lead acetate , settles down at the bottom of each tube leaving clear water above .

Sample CharacterizationThe changes of absorptions at 221 nm were applied to identify the concentrations of lead acetate in each tube , using a LabindiaT60 UV/VIS Spectrophotometer .

Plot showing concentration vs absorbance at 221nm UV radiation

UV-Visible spectroscopy is used to study the interaction of the Fe3O4/OMS-2 with the lead ions. Absorption spectra recorded in the region of 200-300 nm for 0.1 M and 0.05 M lead acetate and composite-lead acetate solution are shown in above Figure. The absorption spectrum of lead acetate90.1 M, 0.05 M) shows the characteristic peaks at 221 nm. The spectra of lead adsorbed in both cases ( original

lead acetate solution and clear water obtained after composite-lead acetate reaction) show difference absortion peaks signifying significant reduction of lead ions from the solution leaving clear water

Result and Discussion

It takes about 30 mins for all suspended particulates in the aqueous phase tobe attracted and accumulated at the magnetic region (Fig. 4), indicating that theas-prepared Fe3O4/OMS-2 nanotubes exhibited remarkable magnetic separability.The sorptive degradation of heavy metals for clear water is one important wastewater treatment method nowadays. Herein, the as-prepared Fe3O4/OMS-2 nanotubes were tested for their adsorptive efficiency in the adsorption of lead acetate under controlled conditions (Fig. ). The prepared Fe3O4/OMS-2 nanotubes showed complete stability during the reaction, and 98.45 % and 99.91%(0.1 M and 0.05 M respectively) of the lead acetate was decomposed .  lead acetate in 3 varying concentrations (0.1 M, 0.01 M, 0.05 M)

Solutions after addition of Fe3O4-MnO2 nanotube composite (image after sedimentation of composite and lead acetate

Samples after magnetic separation of sediment(composite-lead acetate mixtures)

Future workDue to unavailability of X-Ray diffractometer , SEM and due to shortage of time - the characterization( XRD, SEM , DLS) of the Fe3O4-MnO2 nanotube composite and UV analysis of clear water obtained after reaction between the Fe3O4-MnO2 nanotube composite and 0.01 M lead acetate solution was not completed . I plan to follow up on these tasks in the current semester or in the semester break before next semester whenever time permits .

Conclusion

In conclusion, Fe3O4-MnO2 nanotube composite was successfully prepared by grafting Fe3O4 nanoparticles onto the OMS-2 MnO2 nanotubes. The nanotube composite showed excellent adsorption activity for the degradation of lead based compounds from water samples , showed 98.45% and 99.91% reduction in the concentration of lead ions from solution . The residues left at the bottom of the boiling tubes were then magnetically separated from the solution with ease leaving clear water behind . Because of its simple manipulation, the prepared composite may have potential applications in water purification technology.

References

1. Synthesis and Catalytic Activity of Magnetic Cryptomelane-Type Manganese Oxide Nanotubes Hao-Jie Cui • Jian-Wen Shi • Ming-Lai Fu

2. S. L. Suib (2008). Acc. Chem. Res. 41, 479.

3. X. Wang and Y. Li (2002). J. Am. Chem. Soc. 124, 2880.

4. X. F. Shen, Y. S. Ding, J. Liu, J. Cai, K. Laubernds, R. P. Zerger, A. Vasiliev, M. Aindow, and

5. S. L. Suib (2005). Adv. Mater. 17, 805.6. J. Luo, H. T. Zhu, H. M. Fan, J. K. Liang, H. L. Shi, G. H. Rao, J. B.

Li, Z. M. Du, and Z. X. Shen7. (2008). J. Phys. Chem. C 112, 12594.8. H. Huang, C. H. Chen, L. Xu, H. Genuino, J. Garcia-Martinez, H. F.

Garces, L. Jin, C. K. O.9. Kithongo, and S. L. Suib (2010). Chem. Commun. 46, 5945.10. H. J. Cui, X. H. Feng, W. F. Tan, W. Zhao, M. K. Wang, T.

M. Tsao, and F. Liu (2010). Cryst.11. Growth Des. 10, 3355.12. M. Zhou, X. Zhang, J. Wei, S. Zhao, L. Wang, and B. Feng

(2011). J. Phys. Chem. C 115, 1398.13. H.-J. Cui, J.-W. Shi, F. Liu, and M.-L. Fu (2011). J. Mater.

Chem. 21, 18527.14. H.-J. Cui, H.-Z. Huang, M.-L. Fu, B.-L. Yuan, and W. Pearl

(2011). Catal. Commun. 12, 1339.15. B. Li, G. Rong, Y. Xie, L. Huang, and C. Feng (2006). Inorg.

Chem. 45, 6404.16. S. Chen, J. Zhu, Q. Han, Z. Zheng, Y. Yang, and X. Wang

(2009). Cryst. Growth Des. 9, 4356.

17. T. Zhang, X. Zhang, J. Ng, H. Yang, J. Liu, and D. D. Sun (2011). Chem. Commun. 47, 1890.

18. L. Li and D. L. King (2005). Chem. Mater. 17, 4335.19. J. Chen, X. Tang, J. Liu, E. Zhan, J. Li, X. Huang, and W.

Shen (2007). Chem. Mater. 19, 4292.20. S. T. Sriskandakumar, N. Opembe, C. H. Chen, A. Morey, C.

King’ondu, and S. L. Suib (2009).21. J. Phys. Chem. A 113, 1523.22. W. Xiao, D. Wang, and X. W. Lou (2010). J. Phys. Chem. C

114, 1694.23. C. Burda, X. Chen, R. Narayanan, and M. A. EI-Sayed

(2005). Chem. Rev. 105, 1025.24. C. Wu and Y. Xie (2009). Chem. Commun. 40, 5943.25. R. Wang and J. Li (2010). Environ. Sci. Technol. 11, 4282.26. J. H. Pan, X. W. Zhang, A. J. Du, D. D. Sun, and J. O. Leckie

(2008). J. Am. Chem. Soc. 130, 11256.