2908
Calcium manganese oxide nanoparticles for application in water oxidation are synthesized by combination with a carboxylated biopolymer stabilizing agent to form very simple but effective analogues of the photosynthetic PSII oxygen evolving complex .
 Calcium manganese oxide, oxygen
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 Calcium manganese oxide, oxygen