6520
The definite heterojunction interface between SnS ( 2 ) nanosheets and TiO ( 2 ) ( A or R ) nanoparticles were investigated by high resolution transmission electron microscopy ( HRTEM ) and X - ray photoelectron spectroscopy ( XPS ) .
 Chemical: SnS ( 2 ); Chemical: TiO ( 2 ) ( A or R )
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: SnS ( 2 ); Chemical: TiO ( 2 ) ( A or R )