We have shown that an anion radical of C-60 (C-60(center dot-)) is readily formed in a nitrobenzene (NB) solution containing tetraphenylborate by solar-light irradiation. Applying this photochemical reaction of C-60, we examined a voltammetric behavior of C-60(center dot-) by using an electron conductor separating oil-water (ECSOW) system consisting of NB and water (W) phases. Based on the behavior, we can successfully attain spontaneous generation of hydrogen gas in a photovoltaic cell with NB and W phases.