16846
While these processes are dramatically enhanced by an external DC or AC field and electron - donating electrodes , they can be completely prevented by eliminating nanoporosity , depositing a barrier layer , or using an oxidation - resistant electrode .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities:  
Answer:
 None