Evaluation of photocatalytic degradation activity of magnesium aminoclay-titanium dioxide coated activated carbon fiber for malachite green

Abstract

   Magnesium aminoclay-titanium dioxide coated activated carbon fiber (MgAC-TiO₂) was synthesized and proven to have photocatalytic degradation activity on 10 ppm methylene blue [1]. MgAC-TiO₂/ACF in the present study was synthesized again from (3-Aminopropyl) triethoxysilane, ethanol, hydrated magnesium chloride, tetrabutyl titanate and activated carbon fiber (ACF) supplied in Viet Nam, then evaluated for the photocatalytic degradation activity on malachite green at various concentrations. The photocatalytic degradation activities of MgAC-TiO₂/ACF (size of 1 cm × 1 cm) at 10 ppm, 12.5 ppm and 15 ppm malachite green were investigated by sampling the solutions after time intervals of 20 minutes since the systems of MgAC-TiO₂/ACF in malachite green reached adsorption equilibrium and irradiated with 365 nm ultraviolet light. The decrease of malachite green concentration was expressed by the intensity change of absorbance peak at 618 nm. MgAC-TiO₂/ACF was proven to have photocatalytic degradation activity for malachite green under ultraviolet irradiation of 365 nm. The photocatalytic efficiency was inversely affected by malachite green concentration. The photocatalytic malachite green degradation efficiencies of MgAC-TiO₂/ACF (1 cm × 1 cm) at concentrations of 10 ppm, 12.5 ppm and 15 ppm were 27.36 %, 5.34 % and 0.82 %, respectively.