NOVELTY - An electrolysis device (10) comprises: a housing (13), where at least part of the housing permits transmission of light through it; an anode (19) and a cathode (16); a separator (22) disposed in housing to separate anode and cathode, and form anodic reaction zone (28) and cathodic reaction zone (25) within housing; and is configured to form in use at least one fluidized bed comprising reaction medium and photolysis-catalyzing nanoparticles suspended in reaction medium, disposed in housing.    USE - As an electrolysis device, useful as a hydrogen generator for producing hydrogen (claimed).    ADVANTAGE - The photolysis-assisted electrolysis device operates both at high rates and efficiencies. The device uses three-dimensional quality of fluidized bed to eliminate various limitations of prior art photolysis hydrogen generator. Further, function of electrolysis system is improved by assisting reaction with electrons generated by photolysis reaction. This results in synergistic photolytic-electrolytic system that uses less electricity per amount of hydrogen produced, and improves efficiency of either electrolysis and photolysis alone. Unlike traditional electrolysis device, whose efficiency decreases as current increases; electrolysis device with at least one fluidized bed, shows increase in efficiency as current is increased, until a limiting current is reached in which further gas generation disrupts fluidization and percolation pathway, where the limiting current at maximum efficiency is significantly higher in devices with fluidized bed, compared to that in traditional electrolysis system. Also, in the device a reactive surface area is increased by several order of magnitude by using catalyzing nanoparticles in fluidized bed. In addition to surface area of porous or reticulate electrode and nanoparticles infused into the electrode; the fluidized bed configuration capitalizes on additional surface area created by the fluidized catalyzing nanoparticles. The increased catalytic behavior of catalyzing nanoparticles; compared to surface of electrode alone, is high due to very large number of atoms on surface of nanoparticles. The more surface atoms available increase the rate of chemical reactions such as combustion, electrochemical oxidation and reduction reactions, and adsorption. Extremely short electron diffusion paths (e.g. 6 atoms from particle center to edge in 3 nm particles) allow for fast transport of electrons through and into particles for other processes. These properties give nanoparticles unique characteristics unlike those of corresponding conventional (micron and larger) materials i.e. high percentage of surface atoms enhances galvanic events such as splitting of water molecules into its composite gases of hydrogen and oxygen.    DETAILED DESCRIPTION - An electrolysis device (10) comprises: a housing (13), where at least part of the housing permits transmission of light through it; an anode (19) and a cathode (16); a separator (22) disposed in housing to separate anode and cathode, and form anodic reaction zone (28) and cathodic reaction zone (25) within housing; and is configured to form in use at least one fluidized bed comprising reaction medium and photolysis-catalyzing nanoparticles suspended in reaction medium, disposed in housing. The fluidized bed is located in cathodic reaction zone, and/or anodic reaction zone. The fluidized bed further comprises electrolysis-catalyzing nanoparticles suspended in it. When fluidized bed is located in cathodic reaction zone, the electrolysis-catalyzing nanoparticles comprise reduction-catalyzing nanoparticles. When fluidized bed is located in anodic reaction zone, the electrolysis-catalyzing nanoparticles comprise oxidation-catalyzing nanoparticles. The photolysis-catalyzing nanoparticles comprise a metal or semiconductor capable of absorbing photons from light. The photolysis-catalyzing nanoparticles and electrolysis-catalyzing nanoparticles comprise a metal or metal oxide core, and oxide shell having thickness of 5-99% of total particle thickness. The photolysis-catalyzing nanoparticles and electrolysis-catalyzing nanoparticles have effective diameter of (less than 1 mu m, preferably less than 100 nm, especially less than 50 nm). The device further comprises a mirror configured to direct light from light source toward the fluidized bed. INDEPENDENT CLAIMS are included for the following:    (1) a hydrogen generator comprising: a housing comprising first portion that permits transmission of solar rays through it and a second portion; a separator disposed within housing that forms cathodic reaction zone proximate first portion, and anodic reaction zone proximate second portion; a cathode disposed within cathodic reaction zone and an anode disposed within anodic reaction zone, where the generator is configured to form in use fluidized bed comprising reaction medium, and photolysis-catalyzing nanoparticles and further reduction-catalyzing nanoparticles suspended in reaction medium, disposed within cathodic reaction zone; and    (2) method for producing hydrogen involving: providing an electrolysis cell containing fluidized bed comprising reaction medium and photolysis-catalyzing nanoparticles suspended in reaction medium; exposing fluidized bed to light and producing donor electrons; applying a negative current to cathode and producing donor electrons; applying positive current to anode and reducing reaction medium using the donor electrons to produce hydrogen gas.    DESCRIPTION OF DRAWING(S) - The figure shows a top plan view of tubular-shaped photolysis-assisted electrolysis device.    Electrolysis device (10)    Housing (13)    Cathode (16)    Anode (19)    Separator (22)    Cathodic reaction zone (25)    Anodic reaction zone (28)    Mirror (41)