26621
The Co - Ni LDHs with a core - shell structure were fabricated using a facile route from a Co - Ni hydroxide precursor with iodine as a topotactic oxidizer .
 Co, Ni, Co, Ni, hydroxide, iodine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 Co, Ni, Co, Ni, hydroxide, iodine