25711
We investigated CO adsorption on the pristine , Stone - Wales ( SW ) defected , Al - and Si - doped graphenes by using density functional calculations in terms of geometric , energetic and electronic properties .
 CO, Al, Si, graphenes
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 CO, Al, Si, graphenes