This document summarizes a study that synthesized nanocrystalline bismuth phosphate materials using the hot injection method. The study found that a concentration of 2-4M HCl produced single-phase bismuth phosphate materials with particle sizes of 5-7 nm. Different acid types produced similar materials but with different particle shapes. Further research is needed to improve crystallinity, control the phosphorus precursor, and optimize synthesis parameters such as temperature, precursor ratios, and solvents.

1. NANOCRYSTALLINE BISMUTH PHOSPHATE MATERIALS SYNTESIZED VIA HOT INJECTION METHOD By: HartinibintiKhairiOsman Supervised by: Dr. Lee Siew Ling

2. INTRODUCTION

4. varies in its applications and useful in both industry and laboratory scale

5. Various types of nanomaterial have been synthesized

7. eg. BiPO4, BiVO4 etc.

8. various applications, eg. ionic conductor, catalyst etc.

9. Bismuth phosphate material - synthesized via several methods

10. Different ratios of Bi:Poffer different applications

11. Bi:P = 5:1 - 7:1 ionic conductor

12. Bi:P = 10:1 - 16:1  capacitor

13. Hot injection method

14. had synthesized several materials (InP, CdSe, CdS)

15. produced good quality of nanosized and homogenous material

17. Objectives of the Study To synthesize nanocrystalline bismuth phosphate material via hot injection method. To characterize nanocrystalline bismuth phosphate material. To study the effect of parameters in synthesis condition in hot injection method.

18. Significance of the Study Feasibility of synthesizing bismuth phosphate material via hot injection method was studied. Parameters in synthesis condition was tailored in order to obtain good quality nanocrystalline bismuth phosphate material.

19. RESEARCH METHODOLOGY

20. Research Design

21. Experimental Set-up

22. Synthesis of Bismuth Phosphate 8. Filter mixture A and rinse with cold ethanol. 7. Flow argon gas (30 minutes) 6. Inject HCl Ag 9. Dry product at 100˚C for 2 days. 60°C 130°C 4. Insert Ca3P2 190°C 5. Flow argon gas 1. Dissolve MA in ODE at 60°C 2. Add BiAc3 at 130°C (30 minutes) 3. Increase temperature to 190°C (10 minutes)

23. REACTIONS INVOLVED  Based on two-step reactions

24. First-step : In-situ generation of PH3 gas PH3 P2O5 HCl Ag Ca3P2 + 6HCl  2PH3 + 3CaCl2 Ca3P2

25. Second-step : Reaction of PH3 gas with BiAc3 PH3 PH3 + Bi---MA  BiP UnreactedPH3 BiP PH3 BiAc3 BiAc3 + MA + ODE CuSO4

26. Overall reactions involved Ag BiP Generation of PH3 gas Growth of nanocrsytalline BiP

27. RESULTS & DISCUSSION Effect of HCl Concentration Effect of Acid Types

28. Effect of HCl Concentration Physical appearance Bismuth phosphate material using: 2M and 4M HCl – off-white powder 6M, 8M and 10M HCl – beige powder

29. Lin (Cps ) 10 20 30 40 50 60 70 80 90 2 - Theta - Scale XRD Pattern -Bismuth phosphate material using 2M and 4M HClproduced single-phase material of Bi3.69PO.31O6.31 which matched PDF 2000 file number 43-0455. -The Bi:P ratio was 11.9:1. -It was in cubic phase with A=5.47160Ȧ. -This material could be a potential capacitor. 4M HCl Lin (Cps) 2M HCl 2-Tetha-Scale

31. FESEM Micrographs 2M HCl 4M HCl Surface morphology – homogenized Particles shape – spherical

32. FESEM Micrographs 6M HCl 8M HCl 10M HCl Surface morphology – homogenized Particles shape – flower-like Surface morphology – inhomogeneous

33. EDX Analysis Good agreement with XRD analysis (11.9:1) Presence of Cl Minor impurity of P PureBiOCl

34. TEM Images 2M HCl 4M HCl Dispersed bismuth phosphate material after undergone ultrasonic for 15 minutes in toluene solution

35. TEM Images 5.464 nm 6.646 nm 5.941 nm 6.447 nm 7.080 nm 5 nm 5 nm 2M HCl 4M HCl Nanoscale bismuth phosphate material ranging from 5 – 7 nm

36. FTIR Spectra 844.88 3444.18 499.05 1016.83 1384.51 %T 508.04 3444.49 843.00 1016.83 1384.71 4000.0 1400 1000 800 350.0 P-P stretch P-O stretch 4M HCl 2M HCl Wavenumber/cm-1

39. FESEM Micrographs 4M H2SO4 4M HNO3 Surface morphology – homogenized Particles shape – spherical Surface morphology – homogenized Particles shape – flower-like

40. EDX Analysis Not so agree with XRD analysis (11.9:1)

41. FTIR Spectra 1013.9 845.8 3444.5 547.0 %T 844.9 3444.2 1016.8 467.1 1387.0 1385.2 4000.0 1400 1000 800 350. P-P stretch P-O stretch 4 M HNO3 4 M H2SO4 Wavenumber/cm-1

42. CONCLUSION Bismuth phosphate material of Bi3.69PO.31O6.31 (Bi:P ratio = 11.9:1) has been successfully synthesized via hot injection method. This material was crystallinedin cubic phase (A = 5.4716 Ȧ) with the particles size of 5-7 nm. The optimum concentration of HCl that used was 2-4 M. By using different types of acid, similar single phase material of Bi3.69PO.31O6.31 was obtained. However, they were observed in different particle shapes.

43. FUTHER RESEARCH FOR MSc DEGREE

44. Low crystallinity of the bismuth phosphate material was produced. Phosphorus precursor – not sure how much it was produced as gas and reacted with bismuth precursor. Problems to be Solved

45. Gas source – difficult to control, it has its own limitation. Phosphorus in gas form – very dangerous and toxic. Solution: try phosphorus precursor in liquid form.

46. To synthesize bismuth phosphate nanocrystalvia hot injection method. To investigate more parameters in synthesis condition to further optimize the quality of the synthesized bismuth phosphate materials. Objectives of Study

47.  The parameters involved includes: a. Heating temperature b. Ratio of precursor c. Types of reaction solvent d. Types of bismuth source e. Ratio of myristic acid used To study the ionic conductivity of the synthesized nanocrystalline(or nanocrystal?)bismuth phosphate materials.

48. ~ Thank you ~

49. Two-step Reaction In-situ generation of PH3 gas from the Ca3P2 precursor: Reaction of the PH3 gas with the bismuth precursor :

50. Injection of excess HCl towards Ca3P2: Formation of BiCl3: