A process for preparing a catalytic material of an electrode for electrochemical reduction reactions, said material comprising an active phase based on at least one group VIB metal and an electrically conductive support, which process is carried out according to at least the following steps:

a) bringing water into contact with said electrically conductive support,
b) bringing said wet support into contact with at least one metallic acid hydrate comprising at least one group VIB metal, of which the melting point of said metallic acid hydrate is between 20° C. and 100° C., the weight ratio of said metallic acid to said electrically conductive support being between 0.1 and 4,
c) heating, with stirring, to a temperature between the melting point of said metallic acid hydrate and 100° C.,
d) carrying out a sulfurization step at a temperature of between 100° C. and 600° C.

A process for preparing a catalytic material of an electrode for electrochemical reduction reactions, said material comprising an active phase based on at least one group VIB metal and an electrically conductive support, which process is carried out according to at least the following steps:

a) bringing water into contact with said electrically conductive support,
b) bringing said wet support into contact with at least one metallic acid hydrate comprising at least one group VIB metal, of which the melting point of said metallic acid hydrate is between 20° C. and 100° C., the weight ratio of said metallic acid to said electrically conductive support being between 0.1 and 4,
c) heating, with stirring, to a temperature between the melting point of said metallic acid hydrate and 100° C.,
d) carrying out a sulfurization step at a temperature of between 100° C. and 600° C.

A cathode electrode for a gas diffusion electrolytic flow cell that produces a carbon dioxide reduction product by reducing carbon dioxide, wherein the cathode electrode comprises a catalyst layer having a metal complex catalyst, a carbon material and an alkali metal salt, and a gas diffusion layer disposed on the catalyst layer.

A cathode electrode for a gas diffusion electrolytic flow cell that produces a carbon dioxide reduction product by reducing carbon dioxide, wherein the cathode electrode comprises a catalyst layer having a metal complex catalyst, a carbon material and an alkali metal salt, and a gas diffusion layer disposed on the catalyst layer.

A method for synthesizing an intergrown twin Ni.sub.2Mo.sub.6S.sub.6O.sub.2/MoS.sub.2 two-dimensional nanosheet with exposed (00L) crystal planes is disclosed. An Ni-Mo bonded precursor is formed by using an ion insertion method to restrict Ni ions to be located in a lattice matrix of a Mo-based compound; a dinuclear metal sulfide Ni.sub.2Mo.sub.6S.sub.6O.sub.2 is formed by precisely adjusting and controlling a concentration of a sulfur atmosphere and utilizing a reconstruction effect of Ni element in the lattice matrix of the Mo-based compound; and meanwhile, a growth direction of Ni.sub.2Mo.sub.6S.sub.6O.sub.2 is precisely adjusted and controlled by using a method for growing a single crystal in a limited area, so that Ni.sub.2Mo.sub.6S.sub.6O.sub.2 is grown, taking a single crystal MoS.sub.2 as a growth template, with the single crystal MoS.sub.2 alternately along a crystal plane (110) of the single crystal MoS.sub.2, so as to form a twin Ni.sub.2Mo.sub.6S.sub.6O.sub.2/MoS.sub.2 two-dimensional nanosheet in which Ni.sub.2Mo.sub.6S.sub.6O.sub.2and MoS.sub.2 are intergrown.

A method for synthesizing an intergrown twin Ni.sub.2Mo.sub.6S.sub.6O.sub.2/MoS.sub.2 two-dimensional nanosheet with exposed (00L) crystal planes is disclosed. An Ni-Mo bonded precursor is formed by using an ion insertion method to restrict Ni ions to be located in a lattice matrix of a Mo-based compound; a dinuclear metal sulfide Ni.sub.2Mo.sub.6S.sub.6O.sub.2 is formed by precisely adjusting and controlling a concentration of a sulfur atmosphere and utilizing a reconstruction effect of Ni element in the lattice matrix of the Mo-based compound; and meanwhile, a growth direction of Ni.sub.2Mo.sub.6S.sub.6O.sub.2 is precisely adjusted and controlled by using a method for growing a single crystal in a limited area, so that Ni.sub.2Mo.sub.6S.sub.6O.sub.2 is grown, taking a single crystal MoS.sub.2 as a growth template, with the single crystal MoS.sub.2 alternately along a crystal plane (110) of the single crystal MoS.sub.2, so as to form a twin Ni.sub.2Mo.sub.6S.sub.6O.sub.2/MoS.sub.2 two-dimensional nanosheet in which Ni.sub.2Mo.sub.6S.sub.6O.sub.2and MoS.sub.2 are intergrown.

A cathode is provided for electrolysis of water wherein the cathode material comprises a multi-principal element, transition metal dichalcogenide material that has four or more chemical elements and that is a single phase, solid solution. The pristine cathode material does not contain platinum as a principal (major) component. However, a cathode comprising a transition metal dichalcogenide having platinum (Pt) nanosized islands or precipitates disposed thereon is also provided.

A cathode is provided for electrolysis of water wherein the cathode material comprises a multi-principal element, transition metal dichalcogenide material that has four or more chemical elements and that is a single phase, solid solution. The pristine cathode material does not contain platinum as a principal (major) component. However, a cathode comprising a transition metal dichalcogenide having platinum (Pt) nanosized islands or precipitates disposed thereon is also provided.

A synthetic methodology for robust, nanostructured films of cobalt oxide over metal evaporated gold or similar material layer of, e.g., 50 nm, directly onto glass or other substrates via aerosol assisted chemical vapor deposition (AACVD). This approach allows film growth rates in the range of, e.g., 0.8 nm/s, using a commercially available precursor, which is ˜10-fold the rate of electrochemical synthetic routes. Thus, 250 nm thick cobalt oxide films may be generated in only 5 minutes of deposition time. The water oxidation reaction for such films may start at ˜0.6 V vs Ag/AgCl with current density of 10 mA/cm.sup.2 and is achieved at ˜0.75 V corresponding to an overpotential of 484 mV. This current density is further increased to 60 mA/cm.sup.2 at ˜1.5 V (vs Ag/AgCl). Electrochemically active surface area (ECSA) calculations indicate that the synergy between a Au-film, acting as electron sink, and the cobalt oxide film(s), acting as catalytic layer(s), are more pronounced than the surface area effects.

A synthetic methodology for robust, nanostructured films of cobalt oxide over metal evaporated gold or similar material layer of, e.g., 50 nm, directly onto glass or other substrates via aerosol assisted chemical vapor deposition (AACVD). This approach allows film growth rates in the range of, e.g., 0.8 nm/s, using a commercially available precursor, which is ˜10-fold the rate of electrochemical synthetic routes. Thus, 250 nm thick cobalt oxide films may be generated in only 5 minutes of deposition time. The water oxidation reaction for such films may start at ˜0.6 V vs Ag/AgCl with current density of 10 mA/cm.sup.2 and is achieved at ˜0.75 V corresponding to an overpotential of 484 mV. This current density is further increased to 60 mA/cm.sup.2 at ˜1.5 V (vs Ag/AgCl). Electrochemically active surface area (ECSA) calculations indicate that the synergy between a Au-film, acting as electron sink, and the cobalt oxide film(s), acting as catalytic layer(s), are more pronounced than the surface area effects.