Abstract:
Coconut shells (CS) are one of the main domestic wastes that are abundantly used as a precursor
to producing activated carbon black (ACB) for various purposes. This study investigated a lowtemperature
chemical activation method (LTCA) using NaOH to prepare ACB from CS to
apply as the black colourant in toner production. Initially, the cleaned CSs were subjected to a
pyrolysis process at 550 °C for 4 hrs, and the resulting coconut charcoal was activated using
NaOH at 120 °C. The porosity of the resulting ACB was investigated at different charcoal and
NaOH solution volume ratios. The chemical characteristics, surface morphology, surface area
and crystallinity of the ACB, and mineralogy of initial coconut ash were examined using
Fourier-transform infrared (FT-IR) spectroscope and scanning electron microscopy (SEM) and
powder X-ray diffraction (PXRD) analyses. The current study found that the weight percentage
of ash in a CS is 0.6% and consists of SiO2, MgO, CaCO3, MnO, TiO2, CaO, Al2O3, Fe2O3,
P2O5, and fixed carbon. The PXRD shows the increase of graphitic nature with increasing
NaOH volume. The FT-IR proves that ACB consists of carbonyl groups, carboxylic groups,
aromatic C=C bonds and aromatic C-H out-of-plane deform bonds as the main functional
groups, indicating the formation of aromatic compounds. The SEM images indicate that
increasing NaOH volume causes irregular-shaped micropores with large diameters compared
to the low NaOH volume exhibiting spherical micropores. Therefore, it concludes that LTCA
with less NaOH volume causes the slow removal of C as CO3
2- from the ACB and increases the
surface area. In the future, these ACBs will be used to produce toners to identify the eligibility
as the colourant for electrophotography toners.
