Nickel cobalt phosphide-based nanoparticles and methods of making, and electrochemical systems and methods
View Patent ↗The present disclosure is directed to cobalt and nickel cobalt phosphide/phosphate electrocatalyst nanoparticles for catalyzing electrochemical reactions, such as water splitting. The nanoparticles are formed into electrodes that have bi-functional oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) capabilities.
1. A electrode, comprising:
agglomerated nanoparticles; and
a conductor;
wherein the nanoparticles consist essentially of a metal, phosphorus and oxygen; and
wherein the metal is a mixture of nickel and cobalt having a cobalt to nickel ratio in the range of 2:1 to 100:1; and
wherein the cobalt to phosphorus ratio is between 0.8:1 and 1.2:1; and
wherein the nanoparticles have a phosphide core surrounded by an oxide; and
wherein the nanoparticles also have a phosphate phase.
2. An electrochemical device, comprising:
an electrode, comprising:
agglomerated nanoparticles; and
a conductor;
wherein the nanoparticles consist essentially of a metal, phosphorus and oxygen; and
wherein the metal is a mixture of nickel and cobalt having a cobalt to nickel ratio in the range of 2:1 to 100:1; and
wherein the cobalt to phosphorus ratio is between 0.8:1 and 1.2:1; and
wherein the nanoparticles have a phosphide core surrounded by an oxide; and
wherein the nanoparticles also have a phosphate phase.
3. The device of claim 2 , further comprising:
an aqueous electrolyte.
4. A method, comprising:
energizing an electrode in an aqueous electrolyte;
wherein the electrode comprises:
agglomerated nanoparticles; and
a conductor; wherein the nanoparticles consist essentially of a metal, phosphorus and oxygen; and
wherein the metal is a mixture of nickel and cobalt
wherein the metal is a mixture of nickel and cobalt having a cobalt to nickel ratio in the range of 2:1 to 100:1; and
wherein the cobalt to phosphorus ratio is between 0.8:1 and 1.2:1; and
wherein the nanoparticles have a phosphide core surrounded by an oxide; and
wherein the nanoparticles also have a phosphate phase.
5. A water splitting method, comprising:
energizing an electrode in an aqueous electrolyte;
wherein the electrode comprises:
agglomerated nanoparticles; and
a conductor;
wherein the nanoparticles consist essentially of a metal, phosphorus and oxygen; and
wherein the metal is a mixture of nickel and cobalt
wherein the metal is a mixture of nickel and cobalt having a cobalt to nickel ratio in the range of 2:1 to 100:1; and
wherein the cobalt to phosphorus ratio is between 0.8:1 and 1.2:1; and
wherein the nanoparticles have a phosphide core surrounded by an oxide; and
wherein the nanoparticles also have a phosphate phase.
6. The method of claim 5 , further comprising:
generating hydrogen gas.