DOI: https://doi.org/10.55373/mjchem.v26i4.206

Keywords: Titanium dioxide; polymer semiconductor; photoetching; dye photodegradation; immobilized photocatalyst

Abstract

Titanium dioxide with a polymer binder (TiO2/ENR/PVC) was successfully immobilized on a glass substrate by the dip coating technique. The comparison between immobilized photocatalysts with normal photoetching (NP) and acid photoetching (AP) treatments was based on photocatalytic performance and advanced instrumental characterization. A 65 W compact fluorescent lamp and Reactive Red 4 (RR4) dye solution were used to measure the photocatalytic activity for 18 cycles (1 cycle = 10 hours). All the samples were characterized before and after both treatments by FESEM, 3D profilometer, XRD, FTIR and PL to ascertain the surface interactions of the immobilized TiO2 in the presence of hydrochloric acid (HCl), and reaction pathways after photoetching treatment were proposed. The AP sample showed the highest photocatalytic performance with a 0.13 min-1 pseudo 1st order rate constant (k) value, in comparison to the NP sample. Ring-opening and crosslinking reactions after the acid photoetching treatment enhanced photocatalytic activity. Deterioration in the AP and NP samples after the 12th cycle was due to the percolation of the polymer binder on the surface of the samples. Hence, normal and acid photoetching treatments enhanced photocatalytic activity and enabled the immobilized sample to be reused for 18 cycles due to the ring-opening and crosslinking reactions that occurred during these treatments.