Phase developments in Pb(Zn[Ta,Nb,W])O3-PbTiO3 ternary ceramic compositions

Lee, Bong-Ho; Kim, Nam-Kyoung

doi:10.1007/s10832-021-00230-1

Cited by 1 publication

(2 citation statements)

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“…When such a 5 nm thin piece of biochar carbon material is oxygenated on its surfaces, the surface oxygenation may now become measurable even with bulk biochar elemental (O and C) composition analysis. Therefore, the experimental results here are still consistent with the technology concept that ozonization mostly happens on the biochar surfaces.…”

Section: Resultssupporting

confidence: 89%

“…According to our preliminary understanding, , the most significant reactions of O 3 with organic matter are likely based on the cleavage of the carbon double bond, which acts as a nucleophile having excess electrons. The injected O 3 stream may lead to the formation of carbonyl and carboxyl groups on biochar surfaces by reacting with carbon–carbon (C=C) double bonds at ambient pressure and temperature.…”

Section: Introductionmentioning

confidence: 99%

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Biochar Surface Oxygenation by Ozonization for Super High Cation Exchange Capacity

Kharel

Sacko

Feng

et al. 2019

ACS Sustainable Chem. Eng.

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Biochar cation exchange capacity (CEC) is a key property central to better retention of soil nutrients and reduction of fertilizer runoff. This paper reports a breakthrough process to improve biochar CEC value by a factor of nearly 10 through biochar surface oxygenation by ozonization. The CEC value of the untreated biochar was measured to be anywhere between 14 and 17 cmol/kg. A 90 min dry ozonization treatment resulted in an increased biochar CEC value of 109−152 cmol/kg. Simultaneously, the biochar ozonization process resulted in a reduction of biochar pH from 9.82 to as low as 3.07, indicating the formation of oxygen-functional groups including carboxylic acids on biochar surfaces. Using the technique of X-ray photoelectron spectroscopy (XPS), the formation of oxygen-functional groups including carboxylic acids on biochar surfaces have been observed at a nanometer molecular scale following the ozonization treatment. The molar O/C ratio (0.31:1) on ozonized biochar surface as analyzed by XPS was indeed significantly higher than that (0.16:1) of the control biochar surface. The molar O/C ratio from the elemental analysis data also showed an increase from the nonozonized sample (0.077:1) to the dry-ozonized sample (0.193:1). Fourier-transform infrared (FTIR) spectroscopy analysis also showed an increase in the content of oxygen-functional groups in the form of carbonyl groups on biochar surfaces upon ozonization, which can also produce certain amount of oxygenated biochar molecular fragments that may be solubilized by liquid water, potentially leading to greater effects upon application of biochar in soil.

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Section: Resultssupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%