TY - JOUR

T1 - Fern Dicranopteris linearis-derived biochars

T2 - Adjusting surface properties by direct processing of the silica phase

AU - Mai, Nga T.

AU - Nguyen, Nam H.

AU - Tsubota, Toshiki

AU - Shinogi, Yoshiyuki

AU - Dultz, Stefan

AU - Nguyen, Minh N.

N1 - Funding Information: This research was funded by the Vietnam National Foundation for Science & Technology Development (NAFOSTED) under grant number 105.08-2018.300 . An extended part of the research was supported by the Sakura Science Program . X-ray tomographic microscopy was performed with skilful help from Federica Marone at the TOMCAT beamline of the synchrotron facility of the Paul Scherrer Institute, Villigen, Switzerland. Great help from Sarah B. Cichy for the morphological characterization of the fern D. linearis from the tomographic dataset is acknowledged.

PY - 2019/12/20

Y1 - 2019/12/20

N2 - This work specifically emphasizes the effect of the silica phase contained in the fern Dicranopteris linearis (D. linearis), a common shrub occurring widely throughout tropical and subtropical regions, on biochar surface properties. Slow pyrolysis was performed in the temperature range from 400 to 900 °C under various ambient reaction conditions, i.e., non-biochar-oriented conditions (open pyrolysis) and biochar-oriented conditions (closed and N2-supported pyrolysis). The resulting changes in micromorphology and different surface properties, specific surface area and surface charge, were elucidated. Open pyrolysis resulted in excessive decomposition of biomass and condensation of silica, while the closed and N2-supported pyrolysis methods showed notable enhancement of biochar yield. The presence of silica as an inter-embedded part of the fern D. linearis and the derived biochars likely supported a carbon-silica structural model in which these two components might be integrated or decomposed during pyrolysis. In general, joint processing of organic carbon and silica greatly altered the surface properties. At lower temperatures and during N2-supported pyrolysis, condensation of organic compounds limited the development of high surface charge densities. At higher temperatures and during open pyrolysis, intensification of the silica phase was accompanied with an increasing number of charged surface sites, thereby increasing the surface charge density. Based on the porous structure, large surface area (up to 701 m2 g−1) and high surface charge density (up to 0.5 μmol(−) m−2), D. linearis-derived biochars can be highlighted as potential agro-environmental materials.

AB - This work specifically emphasizes the effect of the silica phase contained in the fern Dicranopteris linearis (D. linearis), a common shrub occurring widely throughout tropical and subtropical regions, on biochar surface properties. Slow pyrolysis was performed in the temperature range from 400 to 900 °C under various ambient reaction conditions, i.e., non-biochar-oriented conditions (open pyrolysis) and biochar-oriented conditions (closed and N2-supported pyrolysis). The resulting changes in micromorphology and different surface properties, specific surface area and surface charge, were elucidated. Open pyrolysis resulted in excessive decomposition of biomass and condensation of silica, while the closed and N2-supported pyrolysis methods showed notable enhancement of biochar yield. The presence of silica as an inter-embedded part of the fern D. linearis and the derived biochars likely supported a carbon-silica structural model in which these two components might be integrated or decomposed during pyrolysis. In general, joint processing of organic carbon and silica greatly altered the surface properties. At lower temperatures and during N2-supported pyrolysis, condensation of organic compounds limited the development of high surface charge densities. At higher temperatures and during open pyrolysis, intensification of the silica phase was accompanied with an increasing number of charged surface sites, thereby increasing the surface charge density. Based on the porous structure, large surface area (up to 701 m2 g−1) and high surface charge density (up to 0.5 μmol(−) m−2), D. linearis-derived biochars can be highlighted as potential agro-environmental materials.

KW - Biochar

KW - Fern Dicranopteris linearis

KW - Pyrolysis

KW - Silica

KW - Surface properties

UR - http://www.scopus.com/inward/record.url?scp=85072221226&partnerID=8YFLogxK

U2 - 10.1016/j.colsurfa.2019.123937

DO - 10.1016/j.colsurfa.2019.123937

M3 - Article

AN - SCOPUS:85072221226

VL - 583

JO - Colloids and Surfaces A: Physicochemical and Engineering Aspects

JF - Colloids and Surfaces A: Physicochemical and Engineering Aspects

SN - 0927-7757

M1 - 123937

ER -