Instant synthesis of bespoke nanoscopic photocatalysts with enhanced surface area and photocatalytic activity for wastewater treatment

This study reports on a new perspective in continuous hydrothermal fabrication of highly crystalline nano-catalysts including Mg-Al layered double hydroxide and titanium dioxide. Nano-colloidal catalysts, with consistent product quality were manufactured continually; a set of characterization techniques including XRD, TEM, SEM, and N-2 adsorption-desorption were employed. Mg-Al layered double hydroxide and titanium dioxide demonstrated surface area of 275.7 and 40.2 m(2)/g respectively. The photocatalytic activity of colloidal Mg-Al layered double hydroxide and titanium dioxide were evaluated by degradation of methylene blue under UV-light irradiation and compared to commercial photocatalyst (Zinc oxide). The degradation rate of methylene blue reached 90%, 73%, and 52% for Mg-Al layered double hydroxide, TiO2, and ZnO respectively, after 120 min irradiation time. The increase in layered double hydroxide content from 25 to 100 mg offered an increase in degradation efficiency from 67% to 90%. Under optimal conditions of Mg-Al layered double hydroxide content, H2O2 concentrations, and irradiation time; 100% degradation of methylene blue was achieved. This superior photocatalytic activity of Mg-Al layered double hydroxide compared with TiO2 and ZnO was ascribed to its high surface area and pore volume, enhanced light absorption, its excellent ability to capture organic species and finally efficient charge separation and transfer. This manuscript shaded the light on instant manufacture of Mg-Al layered double hydroxide and its effectiveness as a novel photocatalyst for wastewater treatment. (C) 2017 Published by Elsevier B.V.