NOVELTY - An apparatus (200) comprises a photoanode (210) configured to perform water oxidation, where the photoanode includes a high surface area network (212) of photoanode nanowires (214); and photocathode (220) configured to perform water reduction or carbon dioxide reduction, where photocathode is disposed on a surface of and is in electrical contact with the photoanode, where the photocathode includes a high surface area network (222) of photocathode nanowires (224). The apparatus further comprises an ion conductive polymer (240) infiltrating photoanode and photocathode proximate a region.    USE - As apparatus for producing nanowires (claimed); and as nanowire mesh solar fuel generator.    ADVANTAGE - The apparatus allows production of greater amounts of nanowires. The apparatus provides a surfactant-free, self-seeded, solution-liquid-solid (SLS)12 approach to grow high-quality GaP nanowires (NWs) on a large scale; and allows for visible-light-driven hydrogen production from water reduction using these as-made NWs.    DETAILED DESCRIPTION - An apparatus (200) comprises a photoanode (210) configured to perform water oxidation, where the photoanode includes a high surface area network (212) of photoanode nanowires (214); and a photocathode (220) configured to perform water reduction or carbon dioxide reduction, where the photocathode is disposed on a surface of and is in electrical contact with the photoanode, where the photocathode includes a high surface area network (222) of photocathode nanowires (224). The apparatus further comprises an ion conductive polymer (240) infiltrating the photoanode and the photocathode proximate a region, where the photocathode is disposed on the surface of the photoanode. INDEPENDENT CLAIMS are included for the following:    (1) a method involving fabricating a photoanode membrane including photoanode nanowires; depositing a suspension including photocathode nanowires and a first liquid on the photoanode membrane; filtering, using the photoanode membrane, the photocathode nanowires from the first liquid; and drying the photoanode membrane and the photocathode nanowires. The step of fabricating the photoanode membrane involves: suspending the photoanode nanowires in a second liquid; and filtering the photoanode nanowires from the second liquid using a filter; and    (2) a method of forming nanowires involving: creating nanowires; suspending the nanowires in a liquid; filtering the nanowires from the liquid using a filter; and drying the nanowires. When the nanowires are GaP nanowires, the step of creating the nanowire includes: fabricating GaP nanowires using a solution-liquid-solid (SLS) synthesis technique; washing the GaP nanowires; and eliminating Ga impurities from the GaP nanowires. When the nanowires are WO3 nanowires, the step of creating the nanowires includes: fabricating WO3 nanowires using a hydrothermal synthesis technique; filtering the WO3 nanowires; and washing the WO3 nanowires. The method further involves depositing a co-catalyst on the nanowires.    DESCRIPTION OF DRAWING(S) - The figure shows schematic view illustrating nanowire mesh solar fuels generator.    Nanowire mesh solar fuels generator (200)    Photoanode (210)    High surface area network of photoanode nanowires (212)    Photoanode nanowires (214)    Photoanode co-catalyst particles (216)    Photocathode (220)    High surface area network of photocathode nanowires (222)    Photocathode nanowires (224)    Photocathode co-catalyst particles (226)    Ion conductive polymer (240)