Electrolysis electrode

Abstract

A water purification anode has a first semiconductor contacting a second semiconductor at a heterojunction. The second semiconductor includes TiO 2 and excludes bismuth and niobium. The first semiconductor includes iridium. In some instances, the anode includes a current collector in direct physical contact with the first semiconductor. The anode can be arranged in water such that at least one face of the second semiconductor is in direct physical contact with the water.

1 . A water purification system, comprising:
 an anode having a first semiconductor contacting a second semiconductor at a heterojunction,
 at least one face of the second semiconductor being in direct contact with water that includes organic materials, 
 the second semiconductor including TiO 2  and excludes bismuth, niobium and dopants, and 
 the first semiconductor including iridium. 
   
     
     
         2 . The system of  claim 1 , wherein the second semiconductor excludes Sb, F, Cl, Sb, Mo, W, Nb, and Ta. 
     
     
         3 . The system of  claim 1 , wherein the second semiconductor consists of TiO 2 . 
     
     
         4 . The system of  claim 1 , wherein the first semiconductor is in direct contact with a current collector. 
     
     
         5 . The system of  claim 1 , wherein the first semiconductor includes oxygen. 
     
     
         6 . The system of  claim 5 , wherein the first semiconductor includes one or more stabilizing elements selected from the group consisting of Ta, Si, Sn, Ti, Sb, and Zr. 
     
     
         7 . The system of  claim 5 , wherein the first semiconductor includes tantalum. 
     
     
         8 . The system of  claim 7 , wherein the first semiconductor consists of iridium, tantalum, and oxygen. 
     
     
         9 . The system of  claim 1 , wherein the first semiconductor excludes bismuth and niobium. 
     
     
         10 . The system of  claim 9 , wherein the first semiconductor excludes dopants. 
     
     
         11 . The system of  claim 1 , wherein hydroxyl radicals are physisorbed to the at least one face of the anode. 
     
     
         12 . A water purification anode, comprising:
 a first semiconductor contacting a second semiconductor at a heterojunction,
 at least one face of the second semiconductor being in direct contact with water that includes organic materials, 
 the second semiconductor including TiO 2  and excluding bismuth and dopants, and 
 the first semiconductor including iridium. 
   
     
     
         13 . The anode of  claim 12 , wherein the second semiconductor excludes Sb, F, Cl, Sb, Mo, W, Nb, and Ta. 
     
     
         14 . The anode of  claim 12 , wherein the second semiconductor consists of TiO 2 . 
     
     
         15 . The anode of  claim 12 , wherein the anode includes a current collector in direct contact with the first semiconductor. 
     
     
         16 . A method of operating a water purification system, comprising:
 contacting an anode with water that includes organic materials; and   applying to the anode an anodic potential that is sufficient to generate hydroxyl radicals at the surface of the anode,
 the anode including a first semiconductor contacting a second semiconductor at a heterojunction,
 the second semiconductor including TiO 2  and excluding bismuth, niobium and dopants, and 
 the first semiconductor including iridium. 
 
   
     
     
         17 . The method of  claim 16 , wherein the second semiconductor excludes Sb, F, Cl, Sb, Mo, W, Nb, and Ta.