International Journal of Technology, cilt.16, sa.5, ss.1772-1785, 2025 (ESCI, Scopus)
Problems in light penetration, separation, reusability, and less adaptable reactors remain challenging in photocatalysis, especially when using slurry photocatalysts for wastewater decomposition. The immobilization technique of photocatalysts on compatible support and the reactor setup is crucial in achieving photocatalytic efficacy. This study aims to immobilize ZnO on nylon monofilaments from several precursors. The ZnO-coated nylon monofilament with appropriate characteristics is assembled as a “bottle brush model” catalyst support and integrated into a closed-flow photocatalytic reactor. The photocatalytic decomposition of rhodamine B (RhB) proved the efficacy of the new model catalyst support. The SEM images show the homogeneous surface of the ZnO-coated nylon monofilament, and the ZnO coating was stable in friction and water immersion. The ZnO coating was 44.967 μm; ZnO has aggregated particles, but most of the cluster size was less than 100 nm. The RhB (initial concentration of 5 ppm, 750 ml) photocatalytic activities (0.84 g of ZnO) reached up to 58% color reduction in 30 min, which is higher than the adsorption and photooxidation phenomena, which were only 20% and 13%, respectively. Based on the TOF comparison, the efficacy of this new model catalyst support with the rector design was higher than the activities of the slurry ZnO catalyst and others. The TOF is 0.09-0.30 mg of RhB per g of ZnO per minute, which is higher than the previously reported TOFs of most RhB slurry photocatalysis reported previously (0.003-0.05 mg.g-1.min-1). The present ZnO catalyst with the new model support is reusable twice, with ∼ 10% of catalytic activity reduction.