26765
Using cyclic voltammetry and electrochemical impedance spectroscopy , it was determined that the use of this 3D transparent conducting oxide with a hematite surface catalyst allowed for a seven - fold increase in active surface area for water splitting with respect to its 2D planar counterpart .
 Chemical: oxide; Chemical: hematite
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: oxide, hematite 
Answer:
 Chemical: oxide; Chemical: hematite