A theoretical study of the effect and mechanism of FeN3-doped biochar for greenhouse gas mitigation

Abstract

Paddy fields are a major emission source of greenhouse gases (GHGs) [for instance, methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2)] among agricultural fields. Biochar has been deemed a potential candidate for the reduction of GHGs in paddy fields. However, there is no consistent conclusion that biochar can simultaneously reduce emissions of CH4, N2O, and CO2. Herein, we proposed the FeN3-doped biochar (FG) as an excellent material for GHGs restriction in paddy fields via the first-principles calculation. The computation results indicated that the FG exhibited satisfactory adsorption ability for CH4, CO2, and N2O, which improved the adsorption energies to −1.37 , −1.54, and −2.91 eV, respectively. Moreover, the density of state (DOS) analyses revealed that the factor responsible for FeN3-doped biochar to exhibit excellent adsorption ability was the occurrence of drastic energy up- or down-shift of the electron for Fe d, C p, O p, or N p orbital upon adsorption of CH4, CO2, or N2O. Our study suggested an advanced modified biochar material for reducing the GHGs emissions in paddy fields, in addition to exploring the adsorption properties and mechanisms of FeN3-doped biochar for GHGs mitigation, which provided a strategy to explore biochar modification and efficient emission reduction materials. Graphical Abstract

Applications of Biochar on Carbon Capture, Utilization and Storage (CCUS)

“…The FeN3-doped biochar demonstrated adequate adsorption capabilities for several GHGs in paddy fields (CH4, CO2, and N2O) compared to pure biochar. This enhanced the adsorption energies to -1.37, -1.54, and -2.91 eV, respectively, and altered GHG molecule structure [19]. Additionally, the density of state and partial density of state analyses showed that the occurrence of a significant electron energy up-or downshift of the electron for Fe d, C p, O p, or N p orbitals when CH4, CO2, or N2O is adsorbed is what causes FeN3-doped biochar to demonstrate exceptional adsorption capacity.…”

“…Crop residues 33% soil CO2, 23% soil N2O [5] Potassium doped Over 2.6 Gt CO2-C(eq) per year [14] Corn residues Carbon sequestration increased by 16%, 132% CH4 [15] Maize straw/Pyrolysis and aging Significant reduction of CO2 [16] FeN3-doped Great absorption of CH4, CO2, or N2O [19] , 03011 (2023) ICREE 2023 https://doi.org/10.1051/e3sconf/202342403011 424 E3S Web of Conferences Following the addition of biochar to the soil, there were changes in GHG emissions, including enhanced plant growth (which stores more carbon in vegetation), decreased non-CO2 GHG emissions from the soil, and decreased mineralization of soil organic matter (Table 1).…”