Charcoal is mainly composed by aromatic C but is characterized by several degrees of aromaticity, which complicate its identification and quantification in natural environments by conventional analyses. Charcoal is an almost ubiquitous component of soil, although often occurring in minor amounts. Hence, there is a great interest in studying the charcoal structure and understanding the behavior of charcoal in soils. In soil, it has been demonstrated that the chemical structure of charcoal is also dependant on its particle-size. In this paper we have applied infrared, normal Raman. SERS and SEF spectroscopies to study four size-fractions of charcoal (>2 mm, 2-1 mm, 1-0.5 mm and <0.5 mm) and their alkaline extracts from a burnt Pinus pinea forest. Second derivative FT-IR in agreement with the normal Raman spectroscopy have given information about the size of aromatic rings and the nature of substituted groups in size-fractions of charcoal. Carbon cluster size progressively decreased in the smallest fractions suggesting that higher graphitization and crystallization occurred in the coarsest fraction (>2 mm). The presence of organic N was well evidenced by the vibration of iso-cyanate and cyanamide groups in the fractions. This result is of great environmental importance because N may be immobilized in form of stable molecules like N-heterocyclic poliaromatic structures, and so persists in soils. The soluble organic C (SOC) extracted from charcoal size-fractions did not differ from the bulk charcoal in terms of IR and Raman spectra. Instead SERS and SEF provided further information regarding the ratio between the aromatic component and the aliphatic cross-linking one in studied fractions.

Structural characterization of charcoal size-fractions from a burnt Pinus pinea forest by FT-IR, Raman and surface-enhanced Raman spectroscopies / O. FRANCIOSO; S. SANCHEZ-CORTES; S. BONORA; M.L. ROLDÁN; G. CERTINI. - In: JOURNAL OF MOLECULAR STRUCTURE. - ISSN 0022-2860. - STAMPA. - 994:(2011), pp. 155-162. [10.1016/j.molstruc.2011.03.011]

Structural characterization of charcoal size-fractions from a burnt Pinus pinea forest by FT-IR, Raman and surface-enhanced Raman spectroscopies

CERTINI, GIACOMO
2011

Abstract

Charcoal is mainly composed by aromatic C but is characterized by several degrees of aromaticity, which complicate its identification and quantification in natural environments by conventional analyses. Charcoal is an almost ubiquitous component of soil, although often occurring in minor amounts. Hence, there is a great interest in studying the charcoal structure and understanding the behavior of charcoal in soils. In soil, it has been demonstrated that the chemical structure of charcoal is also dependant on its particle-size. In this paper we have applied infrared, normal Raman. SERS and SEF spectroscopies to study four size-fractions of charcoal (>2 mm, 2-1 mm, 1-0.5 mm and <0.5 mm) and their alkaline extracts from a burnt Pinus pinea forest. Second derivative FT-IR in agreement with the normal Raman spectroscopy have given information about the size of aromatic rings and the nature of substituted groups in size-fractions of charcoal. Carbon cluster size progressively decreased in the smallest fractions suggesting that higher graphitization and crystallization occurred in the coarsest fraction (>2 mm). The presence of organic N was well evidenced by the vibration of iso-cyanate and cyanamide groups in the fractions. This result is of great environmental importance because N may be immobilized in form of stable molecules like N-heterocyclic poliaromatic structures, and so persists in soils. The soluble organic C (SOC) extracted from charcoal size-fractions did not differ from the bulk charcoal in terms of IR and Raman spectra. Instead SERS and SEF provided further information regarding the ratio between the aromatic component and the aliphatic cross-linking one in studied fractions.
2011
994
155
162
O. FRANCIOSO; S. SANCHEZ-CORTES; S. BONORA; M.L. ROLDÁN; G. CERTINI
File in questo prodotto:
File Dimensione Formato  
Journal of Molecular Structure.pdf

Accesso chiuso

Tipologia: Versione finale referata (Postprint, Accepted manuscript)
Licenza: Tutti i diritti riservati
Dimensione 618.54 kB
Formato Adobe PDF
618.54 kB Adobe PDF   Richiedi una copia

I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/459457
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 59
  • ???jsp.display-item.citation.isi??? 56
social impact