Fig. 1. Flow chart of experimental methods

Fig. 2. Transmission electron microscope images of loose and compact BC single particles with different mixing structures. (a1)-(a3) Loose BC particles; (b1)-(b3) compact BC particles

Fig. 3. BC single particle models constructed by EMBS with different coating thickness and coating degree. (a) BC single particle models with D_f=1.8; (b) BC single particle models with D_f=2.6

Fig. 4. E_abs of BC single particles with different mixing structures calculated by DDA, MSTM, and Mie methods. (a) E_abs obtained by DDA, MSTM, and Mie methods when D_f=1.8; (b) E_abs obtained by DDA, MSTM, and Mie methods when D_f=2.6

Fig. 5. SSA of BC single particles with different mixing structures calculated by DDA, MSTM, and Mie methods. (a) SSA of DDA, MSTM, and Mie methods when D_f=1.8; (b) SSA of DDA, MSTM, and Mie methods when D_f=2.6

Fig. 6. Absorption cross section C_abs and absorption efficiency Q_abs of BC single particles without coating (D_f=2.6). (a) Absorption cross section C_abs of BC; (b) absorption efficiency Q_abs of BC

Fig. 7. E_abs, C_abs, and SSA of BC single particles (D_f=2.6, D_p/D_c=2.3, and F=1.00). (a) E_abs; (b) C_abs; (c) SSA

Fig. 8. E_abs, C_abs, and SSA when D_f =2.6, D_p/D_c=2.3, and F=0.50. (a) E_abs; (b) C_abs; (c) SSA