Polyelemental heterostructure nanoparticles and methods of making the same
Disclosed herein are method and design rules for making polyelemental systems with specific heterostructures, including tetra-phase nanopartides with as many as six junctions. In accordance with an embodiment, a method of making a tetra-phase polyelemental nanoparticle using tri-phase nanoparticle architectures can include selecting two or more triphase nanoparticle architectures, wherein the two or more tri-phase nanoparticle architectures are one or more striped tri-phase architectures, one or more pie-shaped tri-phase architectures, or combinations thereof; identifying from the selected two or more tri-phase nanoparticle architectures groups of metals for generating each of the two or more tri-phase nanoparticle architectures; contacting a tip coated with an ink to a substrate to form a nanoreactor, the ink comprising block copolymer and the metals from the groups of metals identified for generating each of the two or more tri-phase nanoparticle architectures; and annealing the nanoreactors under conditions sufficient to synthesize a tetra-phase polyelemental nanoparticle.
1. A method of making a polyelemental nanoparticle, comprising:
depositing a polymer ink solution on a substrate to form a printed indicia of the polymer ink solution, thereby forming a nanoreactor on the substrate, wherein the polymer ink solution comprises a block copolymer, Sn and/or a Sn-precursor, and two or more additional metals and/or additional metal precursors; and
performing a multistage annealing comprising:
a first stage annealing to aggregate metal atoms in the nanoreactor, the first stage annealing comprising exposing the nanoreactor to at least a first, first stage annealing step at a first temperature and a second, first stage annealing step at a second temperature, the first temperature being lower than the second temperature; and
a second stage annealing to reduce the aggregated metal atoms to form the polyelemental nanoparticles, the second stage annealing comprising exposing the nanoreactors to a second stage annealing temperature for a second stage annealing time, wherein the second stage annealing temperature is higher than the second temperature.
2. The method of claim 1 , wherein the two or more additional metals are selected from Au, Ag, Cu, Co, Ni, and Pd.
3. The method of claim 1 or 2 , further comprising making the polymer ink solution by admixing the block copolymer, the Sn and/or the Sn precursor, and the two or more additional metals and/or additional metal precursors in water; and adjusting the pH of the polymer ink solution to a pH of 1.
4. The method of claim 1 , wherein the polymer ink solution comprises the Sn-precursor, the Sn-precursor being selected from one or more of SnCl 4 , SnCl 2 , Na 2 SnO 3 , and K 2 SnO 3 .
5. The method of claim 1 , wherein the first temperature is about 100° C. to about 200° C., and the second temperature is about 200° C. to about 300° C.
6. The method of claim 1 , wherein the first, first stage annealing step comprises exposing the nanoreactor to the first temperature for about 2 hours to about 12 hours.
7. The method of claim 1 , wherein the second first stage annealing step comprises exposing the nanoreactor to the second temperature for about 2 hours to about 12 hours.
8. The method of claim 1 , wherein the second stage annealing temperature is about 500° C. to about 800° C.
9. The method of claim 1 , wherein in the second stage annealing comprises exposing the nanoreactor to the second stage annealing temperature for about 6 hours to about 20 hours.
10. The method of claim 1 , wherein the two or more additional metal precursors are selected from HAuCl 4 .3H 2 O, AgNO 3 , Cu(NO 3 ) 2 .xH 2 O, Co(NO 3 ) 2 .6H 2 O, Ni(NO 3 ) 2 .6H 2 O, and (NH 4 ) 2 PdCl 6 .
11. The method of claim 1 , wherein the block copolymer is present in the polymer ink solution in a concentration of about 1 to about 50 mg/ml.
12. The method of claim 1 , wherein the block copolymer is PEO-b-P2VP or PEO-b-P4VP.
13. The method of claim 12 , wherein the molar ratio of pyridyl groups to the total amount of the Sn and/or a Sn-precursor, and the two or more additional metals and/or additional metal precursors in the ink is between 4:1 and 512:1.
14. The method of claim 1 , wherein the pH of the polymer ink solution is acidic.
15. The method of claim 1 , wherein the pH of the polymer ink solution is 1.
16. The method of claim 1 , wherein the substrate is a TEM grid and/or the polymer ink solution is deposited with a tip, the tip is an AFM tip.
17. The method of claim 1 , wherein the first stage annealing comprises a third, first stage annealing step at a third temperature, the third temperature being higher than the first and second temperatures.
18. The method of claim 17 , wherein the third first stage annealing step comprises exposing the nanoreactors to the third temperature for about 2 hours to about 12 hours.
19. The method of claim 1 , wherein the polymer ink solution is deposited by one or more of scanning probe block copolymer lithography, dip-pen nanolithography, microcontact printing, spin-coating, dip-coating, spray-coating, and drop-casting.
20. The method of claim 1 , wherein 1 to 100 attoliters of the polymer ink solution are deposited per printed indicia.