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 (CH 4 ), nitrous oxide (N 2 O), and carbon dioxide (CO 2 )] 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 CH 4 , N 2 O, and CO 2 . Herein, we proposed the FeN 3 -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 CH 4 , CO 2 , and N 2 O, 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 FeN 3 -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 CH 4 , CO 2 , or N 2 O. 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 FeN 3 -doped biochar for GHGs mitigation, which provided a strategy to explore biochar modification and efficient emission reduction materials. Graphical Abstract