SYNTHESIS OF Pb ALLOY AND CORE/SHELL NANOWIRES

• US 20110001096A1
• Filed: 11/08/2007
• Published: 01/06/2011
• Est. Priority Date: 11/08/2007
• Status: Active Grant

• Current Assignee: Toyota Motor Corporation, Regents of the University of California (University of California), University of California
• Original Assignee: Toyota Motor Corporation
• Inventors: Yang, Peidong, Zhang, Minjuan, Mokari, Taleb
• Granted Patent: US 8,003,021 B2
• Time in Patent Office: Days
• US Class Current: 252/519.14
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 19/007 Tellurides or selenides of metals C01B19/002 takes precedence
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2004/04 obtained by TEM, STEM, STM or AFM
• CPC Class Codes: C01P 2004/16 Nanowires or nanorods, i.e. solid nanofibres with two nearly equal dimensions between 1-100 nanometer
• CPC Class Codes: Y10S 977/762 Nanowire or quantum wire, i.e. axially elongated structure having two dimensions of 100 nm or less
• CPC Class Codes: Y10T 428/2929 Bicomponent, conjugate, composite or collateral fibers or filaments [i.e., coextruded sheath-core or side-by-side type]

Abstract

Embodiments of the present invention are directed to methods of producing PbSe_xY_1-x alloys and methods of producing PbSe/PbY core/shell nanowires. The method of producing PbSe_xY_1-x alloys comprise providing PbSe nanowires, producing a PbY solution where Y═S or Te, adding the PbSe nanowires to an growth solution, and producing PbSe_xY_1-x, nanowire alloys by adding the PbY solution to the heated growth solution comprising PbSe nanowires.

Claims

1. A method for producing PbSe_xY_1-x nanowire alloys where Y═

S or Te comprising;

providing PbSe nanowires;

producing a PbY solution where Y═

S or Te by mixing a Pb precursor solution with a Y precursor solution;

adding the PbSe nanowires to an growth solution at ambient temperature;

heating the growth solution after the addition of PbSe nanowires to a temperature of at least about 150°

C.; and

producing PbSe_xY_1-x nanowire alloys by adding the PbY solution to the heated growth solution comprising PbSe nanowires.

2. The method of claim 1 further comprising isolating the PbSe_xY_1-x nanowire alloys from the heated growth solution by centrifugation.

3. The method of claim 2 further comprising heating the growth solution, cooling the growth solution, adding hexane to the growth solution or combinations thereof prior to isolating the PbSeY nanowires by centrifugation.

4. The method of claim 1 wherein the growth solution, after the addition of PbSe nanowires, is heated to a temperature of from about 190°

C. to about 200°

C.

5. The method of claim 1 wherein the PbY is added dropwise at a rate to the growth solution.

6. The method of claim 1 wherein the growth solution comprises tri-octyl phosphine (TOP) and diphenyl ether (DPE).

7. The method of claim 1 wherein the Y precursor solution comprises sulfur (S) or telluride (Te), and trioctyl phosphine (TOP).

8. The method of claim 1 wherein the PbSe_xY_1-x nanowire alloys comprise a composition of PbSe_0.4S_0.6 and this could be controlled by controlling the amount of PbS that is added to the PbSe nanowires.

9. The method of claim 1 wherein the PbSe_xY_1-x nanowire alloys comprise a thickness of about 10 nm.

10. A method for producing nanowires comprising a PbSe core and a PbS shell comprising the steps of:

providing a core/shell growth solution comprising PbSe nanowires;

heating the core/shell growth solution to a temperature sufficient to produce a PbS shell over the PbSe nanowires;

adding a Pb precursor solution to the core/shell growth solution; and

adding an S precursor solution to the core/shell growth solution after the addition of the Pb precursor to produce nanowires comprising a PbSe core and a PbS shell.

11. The method of claim 10 wherein the core/shell growth solution comprises tri-octyl phosphine (TOP) and diphenyl ether (DPE).

12. The method of claim 10 wherein the S precursor solution comprises S and TOP.

13. The method of claim 10 wherein the core/shell growth solution was heated to a temperature of about 130°

C.

14. The method of claim 10 further comprising heating the core/shell growth solution after the addition of the PbSe nanowires to a temperature of about 130°

C.

15. The method of claim 10 wherein the nanowire comprising a PbSe core and a PbS shell comprise a thickness of about 11 nm.

16. A method for producing nanowires comprising a PbSe core and a PbTe shell comprising the steps of:

providing a Pb precursor solution;

adding a Te precursor solution to the Pb precursor solution to produce a PbTe solution;

providing a core/shell growth solution heated to a temperature of about 150°

C., wherein the core/shell growth solution comprises PbSe nanowires; and

adding the PbTe solution to the core/shell growth solution to form nanowires comprising a PbSe core and a PbTe shell.

17. The method of claim 16 further comprising the step of reheating the core/shell growth solution after the addition of the PbTe solution to a temperature of about 130°

C.

18. The method of claim 16 further comprising isolating the PbSe/PbTe core/shell nanowires from the core/shell growth solution by centrifugation in the presence of toluene or ethanol.

19. The method of claim 16 wherein the core/shell growth solution is heated to a temperature of about 190°

C. prior to the addition of the PbTe solution.

20. The method of claim 16 wherein the Te precursor comprises Te and TOP.

21. The method of claim 16 wherein the Te precursor is added dropwise to the Pb precursor solution.

22. The method of claim 16 wherein the core/shell growth solution comprises TOP and DPE.

23. The method of claim 16 wherein the PbTe shell comprises a thickness of about 5 to about 30 nm.

24. The method of claim 16 wherein the nanowire comprising the PbSe core and PbTe shell comprises a thickness of about 10 to about 45 nm.