Fabrikasi dan Optimasi Reaktor Fotokatalis Komposit TiO2 Nanotube/Polianilina (TNT/PANi) untuk Fotodegradasi Diazinon dengan Variasi Catalyst Loading dan pH Larutan Diazinon

Abstract

This study aims to fabricate a photocatalyst reactor and optimize the effect of solution pH and catalyst loading of TiO₂ Nanotube/Polyaniline (TNT/PANi) composite on diazinon photodegradation under visible light. The TNT/PANi composite was synthesized through a hydrothermal method at 130 °C for 24 hours, followed by slow mixing polymerization using 0.02 M HCl. The reactor was constructed using acrylic as the base material, with dimensions of 20 cm in length, 4 cm in width, and 0.5 cm in height, and an acrylic thickness of 0.3 cm. Photodegradation of diazinon (25 ppm) was carried out with variations in pH (5, 7, 9) and catalyst loading (0.2; 0.4; 0.6 mg/cm2) using direct sunlight for 8 hours. The results showed that the optimum pH was 5, with a removal percentage (%R) of 95.55% at 8 hours, due to the strong electrostatic interaction between the positively charged catalyst surfaces (TiOH₂⁺ and -NH₂⁺) and the negatively charged diazinon (pKa 2.6). The optimum loading of 0.4 mg/cm2 resulted in a %R of 95.55% at 8 hours, the TNT/PANi composite showed potential as an effective photocatalyst for diazinon degradation under direct sunlight.