The present invention relates to a graphene material inlaid with single metal atoms, the preparation method thereof and its application of being used as the catalyst for the electroreduction of carbon dioxide. The graphene material inlaid with single metal atoms comprises single metal atoms and graphene; the single metal atoms are dispersed in the framework of the graphene; and the graphene is at least one selected from N doped graphene and N and S co-doped graphene. The material is used for the electrochemical reduction reaction of carbon dioxide, which significantly improves the utilization efficiency of the metal atoms and enhances the catalytic activity for the electroreduction of carbon dioxide, improves the catalytic stability, inhibits effectively the hydrogen evolution reaction, improves the selectivity for CO product, and broadens the electric potential window of reducing carbon dioxide to generate CO.

A carbon dioxide reduction device of the present invention is a carbon dioxide reduction device comprising a first electrode; at least any one of an electrolyte solution and an ion conducting membrane; and a second electrode, wherein the first electrode is a porous electrode having a porous carbon, and the porous carbon has at least one type of metal-nonmetal element bond represented by M-R, in which M represents a metal element of Groups 4 to 15, and R represents a nonmetal element of Groups 14 to 16.

A carbon dioxide reduction device of the present invention is a carbon dioxide reduction device comprising a first electrode; at least any one of an electrolyte solution and an ion conducting membrane; and a second electrode, wherein the first electrode is a porous electrode having a porous carbon, and the porous carbon has at least one type of metal-nonmetal element bond represented by M-R, in which M represents a metal element of Groups 4 to 15, and R represents a nonmetal element of Groups 14 to 16.

A composition comprising a porous carbon material comprising mesopores, micropores, marcopores, or any combination thereof, is provided. Further, articles comprising the composition and methods of preparing same are provided. Further, a process of oxidizing hydrazine is provided.

A carbon dioxide reduction device of the present invention is a carbon dioxide reduction device comprising a first electrode; at least any one of an electrolyte solution and an ion conducting membrane; and a second electrode, wherein the first electrode is a porous electrode having a porous carbon, and the porous carbon has at least one type of metal-nonmetal element bond represented by M-R, in which M represents a metal element of Groups 4 to 15, and R represents a nonmetal element of Groups 14 to 16.

A carbon dioxide reduction device of the present invention is a carbon dioxide reduction device comprising a first electrode; at least any one of an electrolyte solution and an ion conducting membrane; and a second electrode, wherein the first electrode is a porous electrode having a porous carbon, and the porous carbon has at least one type of metal-nonmetal element bond represented by M-R, in which M represents a metal element of Groups 4 to 15, and R represents a nonmetal element of Groups 14 to 16.

An electrolyzer for splitting molecular water into molecular hydrogen and molecular oxygen using electrical energy comprises an anodic half-cell with an anode and a cathodic half-cell with a cathode. The anodic half-cell and the cathodic half-cell are separated from each other by a separator. The anodic half-cell comprises an anodic electrolyte, which is in contact with the anode. The cathodic half-cell comprises a cathodic electrolyte, which is in contact with the cathode. The anodic half-cell comprises an anodic catalyst. The cathodic half-cell contains at least one cation complex for forming at least one mediator complex. The at least one cation complex is reducible to the mediator complex by taking up at least one electron at the cathode. The mediator complex is a catalytically active chemical complex for splitting the molecular water (H.sub.2O) into molecular hydrogen (H.sub.2) and hydroxide ions (OH.sup.) while releasing at least one electron.

An electrolytic cell and a method of electrochemical oxidation of manganese(II) ions to manganese(III) ions in the electrolytic cell are described. The electrolytic cell comprises (1) an electrolyte solution of manganese(II) ions in a solution of at least one acid; (2) a cathode immersed in the electrolyte solution; and (3) an anode immersed in the electrolyte solution and spaced apart from the cathode. Various anode materials are described including vitreous carbon, reticulated vitreous carbon, woven carbon fibers, lead and lead alloy. Once the electrolyte is oxidized to form a metastable complex of manganese(III) ions, a platable plastic may be contacted with the metastable complex to etch the platable plastic. In addition, a pretreatment step may also be performed on the platable plastic prior to contacting the platable plastic with the metastable complex to condition the plastic surface.

A method of synthesizing a three-dimensional (3D) reduced graphene oxide (RGO) foam embedded with water-splitting nanocatalysts includes providing at least one solution containing at least one precursor of nanocatalysts, and a graphene oxide (GO) aqueous suspension; mixing the GO aqueous suspension with the at least one solution to form a mixture suspension; and performing hydrothermal reaction in the mixture suspension to form a 3D RGO foam embedded with the nanocatalysts.

A method of producing graphene sheets comprising the steps of, (a) forming a carbonaceous powder by electrochemical erosion of a graphite electrode in a molten salt comprising hydrogen ions, (b) recovering the resulting carbonaceous powder from the molten salt liquid, and (c) thermally treating the carbonaceous powder by heating the carbonaceous powder in a non-oxidising atmosphere to produce a thermally treated powder comprising graphene sheets.