Background: Nowadays, effective wastewater treatment has become a hot research topic
in the field of environment. A series of novel activated carbon/ titanium dioxide (AC/TiO2) composites
at various weight ratio were synthesised using the sol-gel method and were characterised using
XRD, SEM-EDX, FT-IR, TGA and surface area analysis.
Method: TiO2 particles were successfully incorporated on the AC surface and were mainly composed
of Ti, O and C atoms. The AC/TiO2 composites were made up of spherical TiO2 particles agglomerated
on the smooth tubular and porous structure of AC. The photocatalytic efficiency was influenced
by the weight proportion of AC:TiO2 and the degradation process was attributed to the adsorption
and photocatalytic processes.
Results: It was found that 2.5 g/L AC/TiO2 at a weight ratio of 3:1 on an initial Malachite Green
concentration of 10 mg/L at 50°C led to a degradation efficiency of 96.3% in 7.5 minutes under a
halogen lamp. A chemical oxygen demand (COD) removal of 96.7% was also recorded. Reusability
of the AC/TiO2 composite and kinetic study of the photodegradation of Malachite Green were also
investigated. The recycled AC/TiO2 composite achieved high catalytic performance (83.1%) after
one catalytic cycle.
Conclusion: The degradation kinetics of Malachite Green at various solution temperatures were fitted
to the pseudo-first-order reactions and the activation energy for the degradation of Malachite
Green was 21.48 kJ/mol. This work demonstrated that AC/TiO2 composite is a promising material
for photocatalytic degradation of organic dyes.