Solid electrode

Abstract

The present invention provides a solid diamond electrode, a reactor, in particular a reactor comprising an anode, a cathode and at least one bipolar electrode having first and second major working surfaces positioned therebetween wherein the at least one bipolar electrode consists essentially of diamond, and methods in which the reactors are used.

1 - 31 . (canceled) 
     
     
         32 . An electrode having at least one major working surface and consisting essentially of diamond wherein the diamond comprises a dopant such that the diamond is conductive and has an electrical resistivity of 1 MΩcm or less and wherein the average concentration of dopant in a region of the at least one of the major working surface, to a depth of 50 nm, is at least 8×10 19  atoms/cm 3  and wherein the electrode has at least one of the following features:
 a) the concentration of dopant atoms in any 1 mm 3  volume does not vary from the concentration of dopant atoms in any other 1 mm 3  volume by more than 50% 
 b) the uniformity of doping through the thickness of the electrode when measured by SIMS at at least five points approximately uniformly spaced through the thickness is such that the maximum dopant concentration is less than about 150% of the mean value and the minimum concentration is greater than about 50% of the mean value; 
 c) a thickness in the range 0.2 mm to 5 mm; 
 d) at least one lateral dimension of at least 10 mm; and 
 e) a surface area of at least 10 cm 2 . 
 
     
     
         33 . (canceled) 
     
     
         34 . An electrode according to  claim 32 , which has a thickness in the range from 0.2 mm to 5 mm. 
     
     
         35 . An electrode according to  claim 32 , which has a longest dimension of at least 10 mm. 
     
     
         36 . An electrode according to  claim 32  having a thickness uniformity such that the minimum thickness as measured using the 17-point array technique is more than 60% of the mean thickness and the maximum thickness measured is less than 135% of the mean thickness. 
     
     
         37 . An electrode according to  claim 32  having an absolute strength measured in three-point bend of greater than 300 MPa. 
     
     
         38 . An electrode according to  claim 32 , wherein the at least one major working surface is the as-grown nucleation face. 
     
     
         39 . An electrode according to  claim 32 , wherein the at least one major working surface is the as-grown growth face. 
     
     
         40 . An electrode according to  claim 32 , which comprises a first major working surface and a second major working surface wherein the first major working surface is the as-grown nucleation face and the second major working surface is the as-grown growth face. 
     
     
         41 . An electrode according to  claim 32 , which is circular. 
     
     
         42 - 83 . (canceled) 
     
     
         84 . An electrode according to  claim 32  wherein the dopant is selected from lithium, beryllium, nitrogen, phosphorus, sulphur, chlorine, arsenic, selenium, and boron. 
     
     
         85 . An electrode according to  claim 84  wherein the dopant is boron. 
     
     
         86 . An electrode according to  claim 32  wherein the electrode has an average dopant concentration of at least 8×10 19  atoms/cm 3 . 
     
     
         87 . An electrode according to  claim 32  wherein the electrical resistivity is about 1×10 19  Ωcm or less. 
     
     
         88 . An electrode according to  claim 32  wherein the electrical resistivity is in the range from about 0.005 Ωcm to about 10 Ωcm. 
     
     
         89 . An electrode according to  claim 32  wherein the at least one major working surface is planar.