21879
Inspired by Pearson ' s hard and soft acid - base ( HSAB ) principle , uniform amorphous Ni ( OH ) 2 nanoboxes with intact shell structures and various sizes are quickly fabricated by deliberately selecting S2 O3 ( 2 - ) as the coordinating etchant toward Cu2 O templates and optimizing the reaction conditions .
 Chemical: Ni ( OH ) 2; Chemical: S2 O3 ( 2 - ); Chemical: Cu2 O
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: Ni ( OH ) 2; Chemical: S2 O3 ( 2 - ); Chemical: Cu2 O