27599
After thermal treatment in a H 2 atmosphere , the bamboo - type TiO 2 nanotubes show large photoelectrochemical water splitting efficiency and supercapacitors performace .
 Chemical: H 2; Chemical: TiO 2
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: H 2; Chemical: TiO 2