Method of synthesizing high-efficiency bifunctional electrocatalysts
View Patent ↗The design of bifunctional catalysts for water splitting by modifying the electronic structure of the catalyst. That bifunctional catalyst that is synthesized is a quaternary FeNi—PSe nanoporous film (FeNi—PSe NF). A self-supported FeNi—PSE NF is synthesized and used as an anode and a cathode in a two-electrode electrolytic cell. The cell is subjected to a water source, and the FeNi—PSe NFs split the water molecules to produce hydrogen fuel. The slightly oxidized FeNi—PSe surface serves as an active site for oxygen evolution reactions, making hydrogen evolution reactions and oxygen evolution reactions well-balanced, thereby improving electrolysis efficiency.
1. A method of synthesizing a bifunctional catalyst for water splitting applications, the method comprising the steps of:
forming a self-supported quaternary iron-doped nickel phosphoselenide nanoporous film by:
performing a top-down anodic conversion of an iron-doped nickel alloy film to form an iron-doped nickel-oxygen nanofilm;
thermally treating, via a tube furnace, the iron-doped nickel-oxygen nanofilm via a phosphorization treatment using a bottom-up chemical vapor deposition, forming an iron-doped nickel-phosphorus nanofilm;
subsequent to forming the iron-doped nickel-phosphorus nanofilm, cooling the tube furnace to room temperature for a predetermined period of time; and
thermally treating, via the tube furnace, the iron-doped nickel-phosphorus nanofilm with selenium vapor, using the bottom-up chemical vapor deposition, to partially substitute selenium for phosphorus, forming a quaternary iron-doped nickel phosphoselenide nanoporous film bifunctional catalyst;
wherein the quaternary iron-doped nickel phosphoselenide nanoporous film bifunctional catalyst comprises high valence nickel;
wherein the selenium stabilizes the bifunctional catalyst and improves an electrical conductivity of the bifunctional catalyst;
wherein the quaternary iron-doped nickel phosphoselenide nanoporous film includes an oxidized surface as an active site for oxygen evolution reactions, such that the quaternary iron-doped nickel phosphoselenide nanoporous film is capable of both hydrogen evolution reactions and oxygen evolution reactions during a water splitting application, thereby improving electrolysis efficiency; and
wherein the quaternary iron-doped nickel phosphoselenide nanoporous film exhibits a rate-determining final electron transfer process (hereinafter “RDS”) for hydrogen evolution reactions, whereby the RDS is dominated by the Heyrovsky step.
2. The method of claim 1 , further comprising the step of forming a plurality of pores disposed through the quaternary iron-doped nickel phosphoselenide nanoporous film, such that the plurality of pores improve a transportation of mass through the nanoporous film.
3. The method of claim 1 , wherein the quaternary iron-doped nickel phosphoselenide nanoporous film includes a thickness of 5 μm.
4. The method of claim 3 , wherein the quaternary iron-doped nickel phosphoselenide nanoporous film is disposed on a surface of an unreacted iron-nickel alloy matrix.
5. The method of claim 1 , wherein the quaternary iron-doped nickel phosphoselenide nanoporous film includes at least 10 wt % iron, at least 65 wt % nickel, at least 0.5 wt % phosphorus, and at least 23 wt % selenium.
6. The method of claim 1 , further comprising the step of subjecting the quaternary iron-doped nickel phosphoselenide nanoporous film to an amount of water.
7. The method of claim 6 , further comprising the step of converting, via the hydrogen evolution reactions, the amount of water into hydrogen fuel that is usable as a renewable energy source.
8. The method of claim 6 , wherein the quaternary iron-doped nickel phosphoselenide nanoporous film exhibits a turnover frequency of about 3.48 s −1 for oxygen evolution reactions.
9. A method of improving electrolysis efficiency during water splitting applications for improved hydrogen fuel production, the method comprising the steps of:
forming a self-supported quaternary iron-doped nickel phosphoselenide nanoporous film by:
performing a top-down anodic conversion of an iron-doped nickel alloy film to form an iron-doped nickel-oxygen nanofilm;
thermally treating, via a tube furnace, the iron-doped nickel-oxygen nanofilm via a phosphorization treatment using a bottom-up chemical vapor deposition, forming an iron-doped nickel-phosphorus nanofilm;
subsequent to forming the iron-doped nickel-phosphorus nanofilm, cooling the tube furnace to room temperature for a predetermined period of time;
thermally treating, via the tube furnace, the iron-doped nickel-phosphorus nanofilm with selenium vapor, using the bottom-up chemical vapor deposition, to partially substitute selenium for phosphorus, forming a quaternary iron-doped nickel phosphoselenide nanoporous film bifunctional catalyst;
forming a plurality of pores disposed through the quaternary iron-doped nickel phosphoselenide nanoporous film;
wherein the quaternary iron-doped nickel phosphoselenide nanoporous film bifunctional catalyst comprises high valence nickel; and
wherein the quaternary iron-doped nickel phosphoselenide nanoporous film exhibits a rate-determining final electron transfer process (hereinafter “RDS”) for hydrogen evolution reactions, whereby the RDS is dominated by the Heyrovsky step;
subjecting the quaternary iron-doped nickel phosphoselenide nanoporous film to an amount of water and flowing the amount of water through the plurality of pores disposed through the quaternary iron-doped nickel phosphoselenide nanoporous film; and
converting the amount of water into hydrogen fuel that is usable as a renewable energy source by splitting the amount of water into hydrogen molecules and oxygen molecules by capturing the oxygen molecules on an oxidized surface of the quaternary iron-doped nickel phosphoselenide nanoporous film to perform oxygen evolution reactions, such that the hydrogen molecules are recovered via hydrogen evolution reactions.
10. The method of claim 9 , wherein the quaternary iron-doped nickel phosphoselenide nanoporous film includes a thickness of 5 μm.
11. The method of claim 10 , wherein the quaternary iron-doped nickel phosphoselenide nanoporous film is disposed on a surface of an unreacted iron-nickel alloy matrix.
12. The method of claim 9 , wherein the quaternary iron-doped nickel phosphoselenide nanoporous film includes at least 10 wt % iron, at least 65 wt % nickel, at least 0.5 wt % phosphorus, and at least 23 wt % selenium.
13. The method of claim 9 , wherein the quaternary iron-doped nickel phosphoselenide nanoporous film exhibits a turnover frequency of about 3.48 s −1 for oxygen evolution reactions.
14. A method of synthesizing a high-efficiency bifunctional electrocatalyst, the method comprising the steps of:
forming a self-supported quaternary iron-doped nickel phosphoselenide nanoporous film by:
performing a top-down anodic conversion of an iron-doped nickel alloy film to form an iron-doped nickel-oxygen nanofilm;
thermally treating, via a tube furnace, the iron-doped nickel-oxygen nanofilm via a phosphorization treatment using a bottom-up chemical vapor deposition, forming an iron-doped nickel-phosphorus nanofilm;
subsequent to forming the iron-doped nickel-phosphorus nanofilm, cooling the tube furnace to room temperature for a predetermined period of time;
thermally treating, via the tube furnace, the iron-doped nickel-phosphorus nanofilm with selenium vapor, using the bottom-up chemical vapor deposition, to partially substitute selenium for phosphorus, forming a quaternary iron-doped nickel phosphoselenide nanoporous film bifunctional catalyst;
forming a plurality of pores disposed through the quaternary iron-doped nickel phosphoselenide nanoporous film; and
wherein the quaternary iron-doped nickel phosphoselenide nanoporous film bifunctional catalyst comprises high valence nickel;
wherein the quaternary iron-doped nickel phosphoselenide nanoporous film includes at least 10 wt % iron, at least 65 wt % nickel, at least 0.5 wt % phosphorus, and at least 23 wt % selenium;
wherein the selenium stabilizes the bifunctional catalyst and improves an electrical conductivity of the bifunctional catalyst;
wherein the quaternary iron-doped nickel phosphoselenide nanoporous film includes an oxidized surface as an active site for oxygen evolution reactions, such that the quaternary iron-doped nickel phosphoselenide nanoporous film is capable of both hydrogen evolution reactions and oxygen evolution reactions during a water splitting application, thereby improving electrolysis efficiency;
wherein the quaternary iron-doped nickel phosphoselenide nanoporous film exhibits a rate-determining final electron transfer process (hereinafter “RDS”) for hydrogen evolution reactions, whereby the RDS is dominated by the Heyrovsky step; and
wherein the iron-doped nickel phosphoselenide nanoporous film is disposed upon at least one portion of a surface of an unreacted iron-nickel alloy.
15. The method of claim 14 , wherein the quaternary iron-doped nickel phosphoselenide nanoporous film includes a thickness of 5 μm.
16. The method of claim 14 , further comprising the step of subjecting the quaternary iron-doped nickel phosphoselenide nanoporous film to an amount of water.
17. The method of claim 16 , further comprising the step of flowing the amount of water through the plurality of pores disposed through the quaternary iron-doped nickel phosphoselenide nanoporous film.
18. The method of claim 16 , further comprising the step of converting, via the hydrogen evolution reactions, the amount of water into hydrogen fuel that is usable as a renewable energy source.
19. The method of claim 16 , wherein the quaternary iron-doped nickel phosphoselenide nanoporous film exhibits a turnover frequency of about 3.48 s −1 for oxygen evolution reactions.