Water splitting method and system

Abstract

An electrode is presented for use in an oxidation process. The electrode comprises a substrate having an electrically conductive surface carrying a chiral system. The chiral system is configured for controlling spin of electrons transferred between the substrate and electrolyte during the oxidation process.

1 . An electrode for use in an oxidation process comprising a substrate having an electrically conductive surface carrying a chiral system, wherein said chiral system is configured for controlling the spin of electrons transferred between the substrate and electrolyte. 
     
     
         2 . The electrode of  claim 1 , wherein said chiral system comprises at least one of organic and inorganic matter having chiral properties. 
     
     
         3 . The electrode of  claim 1 , wherein said chiral system comprises at least one of chiral molecules and chiral polymer. 
     
     
         4 . The electrode of  claim 1 , wherein said chiral system is configured as a single- or multi-layer structure. 
     
     
         5 . The electrode of  claim 4 , wherein said chiral system comprises a self-assembled monolayer of the chiral molecules. 
     
     
         6 . The electrode of  claim 1 , wherein said chiral system includes at least one of the following: oligopeptides, amino acids, DNA, helicenes, and chiral conductive polymer. 
     
     
         7 . The electrode of  claim 1 , wherein said chiral system is either chemically bound to said surface of the substrate or physically adsorbed on it. 
     
     
         8 . The electrode of  claim 1 , wherein said substrate is made of at least one metal or semiconductor. 
     
     
         9 . The electrode of  claim 1 , wherein said electrode is configured as a photoabsorber. 
     
     
         10 . The electrode of  claim 9 , wherein said substrate is configured as a photoabsorber. 
     
     
         11 . The electrode of  claim 9 , comprising at least one layer of photoabsorber carried by the substrate. 
     
     
         12 . The electrode of  claim 11 , wherein said chiral system comprises at least one layer of photoabsorber having chiral properties. 
     
     
         13 . The electrode of  claim 11 , comprising photoabsorbing nanoparticles bound to the substrate via said chiral system. 
     
     
         14 . An electrochemical cell comprising the electrode of  claim 1 . 
     
     
         15 . A water splitting method comprising operating an electrochemical cell to cause oxidation of water at an electrode of the electrochemical cell, while aligning spins of electrons released by oxygen during said oxidation. 
     
     
         16 . The method of  claim 15 , wherein said aligning of the spins of electrons is performed by using a chiral system in the electrochemical cell. 
     
     
         17 . The method of  claim 16 , wherein said operating of the electrochemical cell comprises excitation of an anode resulting in the formation of electrons and electron holes causing the oxidation of water at the anode by holes and alignment of the spins of electrons by the chiral system at the anode. 
     
     
         18 . The method of  claim 17 , wherein said anode is configured as a photoabsorber, said excitation being light-induced excitation. 
     
     
         19 . The method of  claim 15 , wherein said operating of the electrochemical cell comprises application of a potential difference between anode and cathode electrodes; transport of H+ ions from the anode to a cathode through an electrolyte and transport of electrons from the anode to the cathode through an external circuit; and reduction of hydrogen ions at the cathode by electrons to thereby produce hydrogen.