Effects of carbonyl group formation on ammonia adsorption of porous carbon surfaces.
In this work, the effects of different surface functional groups on the ammonia adsorption of porous carbons modified by electrochemical treatment in acidic solution (HNO3) under different current densities were investigated. The surface properties of the treated carbons were observed by Boehm's titration and X-ray photoelectron spectroscopy (XPS). It was found that the oxygen content of the carbons increased with increasing current density from the XPS results. However, the pH and acid values of the treated carbons slightly decreased in a sample prepared in 0.8 A/m2 of current density (ACs-0.8). This result indicated that the surface acidity could be reduced according to the characteristics of surface functional groups introduced. From the XPS results, it was found that the growth of CO groups was predominant at ACs-0.8. This result was also supported by an ammonia gas removal test. The adsorption capacity increased to ACs-0.4, but then began to decrease at AC-0.8.
Kim
Byung-Joo
BJ
Department of Green Chemistry & Environmental Biotechnology, University of Science & Technology, P.O. Box 107, Yuseong, Daejeon 305-600, Republic of Korea.
Park
Soo-Jin
SJ
D000327:Adsorption; D000641:Ammonia / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D004563:Electrochemistry; D006863:Hydrogen-Ion Concentration; D017942:Nitric Acid / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D016062:Porosity; D013057:Spectrum Analysis; D013499:Surface Properties; D014965:X-Rays
D017942:Nitric Acid; D002244:Carbon; D000641:Ammonia; D010100:Oxygen