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US 2026/0002273 A1Published application
Water splitting electrode
AssigneeKing Fahd University of Petroleum and Minerals
InventorsMohamed Jaffer Sadiq MOHAMED, Muhammad Ashraf Gondal
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Abstract
An electrode includes an electrically conductive substrate and a layer of a molybdenum-doped zinc/cobalt oxide (ZnCo2-xMoxO4). The surface of the electrically conductive substrate is at least partially covered by the layer of ZnCo2-xMoxO4, where x is a positive number equal to or less than about 0.1, and the layer of the ZnCo2-xMoxO4 includes spherical-shaped particles. The electrode has a Tafel slope from 75 millivolts per second (mV/s) to 115 mV/s, and a potential of 0.27 to 0.30 volts relative to the reversible hydrogen electrode (VRHE) at a current density of about 50 mA/cm2 for a duration of at least 40 hours.
Claims20
1:
- An electrode for water splitting, comprising:
- an electrically conductive substrate formed from glassy carbon;
- and
- a layer comprising a sulfonated tetrafluoroethylene-based fluoropolymer-copolymer and a molybdenum-doped zinc/cobalt oxide (ZnCo2-xMoxO4) at least partially covering a surface of the electrically conductive substrate;
- wherein x is a positive number equal to or less than about 0.1;
- and
- wherein the layer of the ZnCo2-xMoxO4 comprises spherical shaped particles.
4 more elements
(canceled)
(canceled)
4:
- The electrode of claim 1, wherein the spherical shaped particles of the ZnCo2-xMoxO4 have an average particle size of 2 micrometers (μm) to 10 μm.
5:
- The electrode of claim 1, wherein the spherical shaped particles of the ZnCo2-xMoxO4 comprise a porous matrix of interconnected nanoneedles, and wherein the interconnected nanoneedles have an average width of from 0.1 nanometers (nm) to 3 nm.
6:
- The electrode of claim 1, wherein the spherical shaped particles of the ZnCo2-xMoxO4 are aggregated.
7:
- The electrode of claim 1, wherein x is 0.06, and wherein the electrode has an overpotential of about 195 millivolts (mV) relative to the reversible hydrogen electrode (mVRHE) at a current density of about 10 milliamperes per square centimeter (mA/cm2).
8:
- The electrode of claim 1, wherein x is 0.06, and wherein the electrode has an overpotential of about 280 mVRHE at a current density of about 50 mA/cm2.
9:
- The electrode of claim 1, having a Tafel slope of from 75 millivolts per second (mV/s) to 115 mV/s.
10:
- The electrode of claim 1, wherein x is 0.06, and wherein the electrode has a Tafel slope of about 81.4 mV/s.
11:
- The electrode of claim 1, having a potential of from 0.27 to 0.30 volts relative to the reversible hydrogen electrode (VRHE) at a current density of about 50 mA/cm2 for a duration of at least 40 hours.
12:
- A method of making the electrode of claim 1, comprising preparing the ZnCo2-xMoxO4 by:
- mixing and dissolving a Zn salt, a Co salt, a Mo salt, and urea in a solvent to form a mixture;
- heating the mixture at a temperature of about 120 degrees Celsius (° C.) to form a precursor compound in the form of a precipitate;
- and
- separating the precursor compound from the mixture and calcining at a temperature of from 250 to 450° C.
2 more elements
13:
- The method of claim 12, wherein the Zn salt comprises zinc acetylacetonate, zinc sulfate, zinc acetate, zinc citrate, zinc iodide, zinc chloride, zinc perchlorate, zinc nitrate, zinc phosphate, zinc triflate, zinc bis(trifluoromethanesulfonyl)imide, zinc tetrafluoroborate, zinc bromide, and/or its hydrate.
14:
- The method of claim 12, wherein the Co salt comprises cobalt acetylacetonate, cobalt sulfate, cobalt acetate, cobalt citrate, cobalt iodide, cobalt chloride, cobalt perchlorate, cobalt nitrate, cobalt phosphate, cobalt triflate, cobalt bis(trifluoromethanesulfonyl)imide, cobalt tetrafluoroborate, cobalt bromide, and/or its hydrate.
15:
- The method of claim 12, wherein the Mo salt is ammonium molybdate.
16:
- The method of claim 12, wherein the calcining the precursor compound is performed at a temperature of about 350° C. for 1 to 6 hours.
17:
- The method of claim 12, further comprising:
- mixing the ZnCo2-xMoxO4, one or more solvents, and the sulfonated tetrafluoroethylene-based fluoropolymer-copolymer to form a slurry;
- and
- drop-casting the slurry onto a surface of the GC substrate to form a sample;
- and
- drying the sample.
3 more elements
18:
- The method of claim 17, wherein the ZnCo2-xMoxO4 is present on the surface of the GC substrate in an amount of from 0.25 milligrams per square centimeter (mg/cm2) to 0.32 mg/cm2 of a surface area of the GC substrate in contact with the slurry.
19:
- A method for electrochemical water splitting, comprising:
- applying a potential between a counter and a working electrode in an electrochemical cell containing an electrolyte to form hydrogen and oxygen;
- and
- separately collecting H2-enriched gas and O2-enriched gas;
- wherein the working electrode comprises the electrode of claim 1;
- and
- wherein the electrolyte comprising an aqueous solution of a base at a concentration of 0.05 molar (M) to 5 M.
4 more elements
20:
- The method of claim 19, wherein the base is at least one selected from the group consisting of sodium hydroxide (NaOH), potassium hydroxide (KOH), lithium hydroxide (LiOH), barium hydroxide (Ba(OH)2), and calcium hydroxide (Ca(OH)2).
Dependencies are inferred from the claim text.