14761
The results show that an appropriate amount of oxygen supply is crucial for uniform transformation from Cu NWs ( average diameter ~ 50 nm ) into Cu oxide nanotube arrays .
 Chemical: oxygen; Chemical: Cu; Chemical: Cu oxide
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: oxygen; Chemical: Cu; Chemical: Cu oxide