A porous transparent electrode is formed where a film comprising of semiconducting nanoparticles is decorated with polyoxometalates (POMs) bonded to their surfaces. The semiconducting nanoparticles are transparent metal oxide. The semiconducting nanoparticles include tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), or titanium dioxide (TiO.sub.2). In an embodiment, the POM is [SiW.sub.12O.sub.40].sup.4−; [α-P.sub.2W.sub.18O.sub.62].sup.6−; or [α.sub.2-P.sub.2W.sub.17O.sub.61].sup.10−. The semiconducting nanoparticles bond to the POM through a combination of electrostatic interactions and hydrogen bonds. The porous transparent electrode can be placed in a protonated form or ion-paired with alkali metal cations or tetraalkylammonium cations.

The present disclosure relates to a hydrogen evolution apparatus including an AC power source, a semiconductor electrode and a counter electrode connected to the AC power source, an electrolyte in which the semiconductor electrode is immersed, and a light source which irradiates light on the semiconductor electrode, in which the semiconductor electrode includes a conductive substrate and n-type semiconductor particles dispersed on a p-type semiconductor matrix or p-type semiconductor particles dispersed on an n-type semiconductor matrix which is vertically grown from the conductive substrate.

A device includes a substrate having a surface, an array of conductive projections supported by the substrate and extending outward from the surface of the substrate, a plurality of catalyst nanoparticles disposed over the array of conductive projections, and an oxide layer covering the plurality of catalyst nanoparticles and the array of conductive projections. The oxide layer has a thickness on the order of a size of each catalyst nanoparticle of the plurality of catalyst nanoparticles.

A device includes a substrate having a surface, an array of conductive projections supported by the substrate and extending outward from the surface of the substrate, a plurality of catalyst nanoparticles disposed over the array of conductive projections, and an oxide layer covering the plurality of catalyst nanoparticles and the array of conductive projections. The oxide layer has a thickness on the order of a size of each catalyst nanoparticle of the plurality of catalyst nanoparticles.

A photoelectrode includes a fluorine-doped tin oxide (FTO) substrate, and a layer of graphitic-poly(2,4,6-triaminopyrimidine) (g-PTAP) nanoflakes at least partially covering a surface of the FTO substrate. Further, the g-PTAP nanoflakes have a width of 0.1 to 5 micrometers (m). In addition, a method for producing the photoelectrode, and a method for photocatalytic water splitting, in which the photoelectrode is used.

A photoelectrode includes a fluorine-doped tin oxide (FTO) substrate, and a layer of graphitic-poly(2,4,6-triaminopyrimidine) (g-PTAP) nanoflakes at least partially covering a surface of the FTO substrate. Further, the g-PTAP nanoflakes have a width of 0.1 to 5 micrometers (m). In addition, a method for producing the photoelectrode, and a method for photocatalytic water splitting, in which the photoelectrode is used.

A radiation-assisted (typically solar-assisted) electrolyzer cell and panel for high-efficiency hydrogen production comprises a photoelectrode and electrode pair, with said photoelectrode comprising either a photoanode electrically coupled to a cathode shared with an anode, or a photocathode electrically coupled to an anode shared with a cathode; electrolyte; gas separators; all within a container divided into two chambers by said shared cathode or shared anode, and at least a portion of which is transparent to the electromagnetic radiation required by said photoanode (or photocathode) to apply photovoltage to a shared cathode (or anode) that increases the electrolysis current and hydrogen production.

A carbon dioxide gas-phase reduction apparatus includes: an oxidation tank including an oxidation electrode; a reduction tank which is adjacent to the oxidation tank and into which carbon dioxide is supplied when the inside of the reduction tank is empty; and a porous reduction electrode-supporting electrolyte membrane disposed between the oxidation tank and the reduction tank. The porous reduction electrode-supporting electrolyte membrane is a joint body obtained by joining a porous reduction electrode formed by dispersing a first electrolyte membrane inside voids and a second electrolyte membrane. The second electrolyte membrane is disposed on the oxidation tank side. The porous reduction electrode is disposed on the reduction tank side, connected to the oxidation electrode by a conducting wire, and performs a reduction reaction with the carbon dioxide in the reduction tank by electrons flowing through the conducting wire.

A carbon dioxide gas-phase reduction apparatus includes: an oxidation tank including an oxidation electrode; a reduction tank which is adjacent to the oxidation tank and into which carbon dioxide is supplied when the inside of the reduction tank is empty; and a porous reduction electrode-supporting electrolyte membrane disposed between the oxidation tank and the reduction tank. The porous reduction electrode-supporting electrolyte membrane is a joint body obtained by joining a porous reduction electrode formed by dispersing a first electrolyte membrane inside voids and a second electrolyte membrane. The second electrolyte membrane is disposed on the oxidation tank side. The porous reduction electrode is disposed on the reduction tank side, connected to the oxidation electrode by a conducting wire, and performs a reduction reaction with the carbon dioxide in the reduction tank by electrons flowing through the conducting wire.

Systems and methods for providing alternative fuel, in particular hydrogen photocatalytically generated by a system comprising photoactive nanoparticles and a nitrogenase cofactor are provided. In one aspect, the system includes a water soluble cadmium selenide nanoparticle (CdSe) surface capped with mercaptosuccinate (CdSe-MSA) and a NafY.FeMo-co complex comprising a NafY protein and an iron-molybdenum cofactor (FeMo-co), wherein the CdSe-MSA and NafY.FeMo-co complex are present in about 1:2 to 1:10 molar ratio.