Apparatus and method for photo-chemical oxidation are disclosed herein. In one embodiment, a method for regenerating a dialysis fluid includes: flowing the dialysis fluid between an anode and a cathode of a dialysis system, where the anode comprises a plurality of nanostructures; illuminating the anode with a source of light; flowing oxygen through the cathode toward the dialysis fluid; and converting urea in the dialysis fluid into CO2, N2 and H2O thereby regenerating the dialysis fluid.