This is a system for generating and supplying a hydrogen gas from water by water splitting using a carbon electrode containing ethylidyne without any external electric power, which system comprises A) a carbon electrode containing ethylidyne, B) an alkaline electrolyte water solution and C) a metal electrode selected from group consisting of a typical metal including zinc, aluminum and magnesium and a transition metal including copper, wherein the carbon electrode containing ethylidyne and the metal electrode are brought into contact with or opposed to each other in the alkaline electrolyte water solution, and the water is decomposed by the effect of ethylidyne to generate a hydrogen gas according to the following reaction.

CH.sub.3C+O.fwdarw.CH.sub.3CO.sup.++e−

2H.sup.++2e−.fwdarw.H.sub.2↑

as shown in FIG. 1A

A device can include: an electrode including a carbon-nitride refluxed-graphene-oxide (C.sub.3N.sub.4-rGO) nanosheet; and ruthenium ions incorporated into the C.sub.3N.sub.4-rGO nanosheet.

A device can include: an electrode including a carbon-nitride refluxed-graphene-oxide (C.sub.3N.sub.4-rGO) nanosheet; and ruthenium ions incorporated into the C.sub.3N.sub.4-rGO nanosheet.

A CoVO.sub.x composite electrode and method of making is described. The composite electrode comprises a substrate with an average 0.5-5 μm thick layer of CoVO.sub.x having pores with average diameters of 2-200 nm. The method of making the composite electrode involves contacting the substrate with an aerosol comprising a solvent, a cobalt complex, and a vanadium complex. The CoVO.sub.x composite electrode is capable of being used in an electrochemical cell for water oxidation.

A CoVO.sub.x composite electrode and method of making is described. The composite electrode comprises a substrate with an average 0.5-5 μm thick layer of CoVO.sub.x having pores with average diameters of 2-200 nm. The method of making the composite electrode involves contacting the substrate with an aerosol comprising a solvent, a cobalt complex, and a vanadium complex. The CoVO.sub.x composite electrode is capable of being used in an electrochemical cell for water oxidation.

According to one embodiment of the present invention, there is provided a catalyst compound, which comprises a compound of Chemical Formula 1 below and catalyzes the process of oxidizing 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA):

NiCo.sub.xP.sub.y  [Chemical Formula 1]

(wherein x and y are the molar ratio for Ni contained in the catalyst compound, 0<x<1, 0<y<1).

Some examples of a method for manufacturing an electrode material for electrolytic hydrogen generation are described. Tungsten salt and nickel salt are mixed in a determined molar ratio on a carbon support by effectively controlling synthesis temperature and composition. Water and adsorbed oxygen, produced by mixing the tungsten salt and nickel salt are removed. Then, methane gas is flowed over the mixture resulting in the electrode material. The electrode material is suitable for use as a catalyst in electrolytic hydrogen generation processes, for example, at an industrial scale, to produce large quantities of hydrogen.

Some examples of a method for manufacturing an electrode material for electrolytic hydrogen generation are described. Tungsten salt and nickel salt are mixed in a determined molar ratio on a carbon support by effectively controlling synthesis temperature and composition. Water and adsorbed oxygen, produced by mixing the tungsten salt and nickel salt are removed. Then, methane gas is flowed over the mixture resulting in the electrode material. The electrode material is suitable for use as a catalyst in electrolytic hydrogen generation processes, for example, at an industrial scale, to produce large quantities of hydrogen.

An electrocatalyst comprising molybdenum disulfide nanosheets with dispersed iron phosphide nanoparticles is described. The molybdenum disulfide nanosheets may have an average length in a range of 300 nm-1 μm and the iron phosphide nanoparticles may have an average diameter in a range of 5-20 nm. The electrocatalyst may have an electroactive surface area in a range of 10-50 mF.Math.cm.sup.−2 when deposited on a working electrode for use in a hydrogen evolution reaction.

An electrocatalyst comprising molybdenum disulfide nanosheets with dispersed iron phosphide nanoparticles is described. The molybdenum disulfide nanosheets may have an average length in a range of 300 nm-1 μm and the iron phosphide nanoparticles may have an average diameter in a range of 5-20 nm. The electrocatalyst may have an electroactive surface area in a range of 10-50 mF.Math.cm.sup.−2 when deposited on a working electrode for use in a hydrogen evolution reaction.