Table 1 lists the data on the BET surface area, BJH pore diameter, and total pore volumes, and Figs. 4–6 (supporting information) show typical isotherms of NSB, CC and CTC (∼25 and 170 nm). The NSB-25 showed Z-YVAD-FMK fair BET surface area (30 m2/g), total pore volume (0.086 cm3/g) and BJH pore diameter (116 Å). A large increase in the BET surface area was observed (30–82 m2/g) upon the preparation of the carbon cage (CC-25). Consequently, a decrease in the BJH pore diameter from 116 to 58 Å and a tiny rise in total pore volume from 0.086 to 0.120 cm3/g was observed. On the other hand, a small decrease in the BET surface area of 82–69 m2/g, pore volume from 0.120 to 0.107 cm3/g and a small increase in the pore diameter from 58 to 61 Å were observed. This supports the suggested phenomenon of filling the internal pores of CC-25 with tungsten nanoparticles (CTC-25). NSB-170 showed a high BET surface area (163 m2/g), total pore volume (0.290 cm3/g) and BJH pore diameter (71 Å). A large increase in the BET surface area was observed (163–212 m2/g) upon the preparation of CC-170. Consequently, an increase in the BJH pore diameter (from 71 to 162 Å) and total pore volume (from 0.290 to 0.857 cm3/g) were observed. Upon tungsten incorporation in CC-170, however, a small decrease in BET surface area of 212–180 m2/g, pore volume from 0.857 to 0.749 cm3/g and almost unchanged pore diameter from 162 to 161 Å were noticed, suggesting green algae the internal pores of the CC-170 were occupied by the tungsten nanoparticles (CTC-170). This indicates that the structure of the MCNRs had been maintained after modification.