The heat treatment effect on the adsorption capabilities of nanoporous carbon particles
derived from Zeolitic Imidazolate Framework-8 (ZIF-8) was investigated at 600, 1000 and
1200 ̊C in this study. The results showed that heat treatment at 1000 ̊C had a significant effect
on the adsorption capacity of ZIF-8 (almost 10 times) for the removal of methylene blue
(MB) dye from water. Nanoporous carbons were synthesized by direct carbonization of ZIF-
8. SEM and TEM images showed that the carbon resulting from ZIF-8 carbonization at
various temperatures retained the original structure and morphology of ZIF-8. The carbon
nanoparticles carbonized at 1000 ̊C exhibited outstanding adsorption capacities (186.3 mg/g)
compared to nanoparticles carbonized at 600 ̊C (49.5 mg/g) and 1200 ̊C (36.7 mg/g) as well
as ZIF-8 (19.5 mg/g) due to the change in surface charge and pore size distribution. The
surface functionalities of materials were also characterized by Raman Spectroscopy, N2 adsorption-desorption, FTIR and TGA. The surface charge of the carbon particles changed
from positive (ZIF-8) to negative as a result of conversion to carbon confirmed by zeta
potential of the samples. The ZIF-8 derived carbon nanoparticles were found to be efficient
adsorbents for water treatment purposes due to the satisfactory adsorption properties such as
high adsorption capacity and good wettability.