Highly efficient removal of crystal violet dye from water by MnO2 based nanofibrous mesh/photocatalytic process

Abstract

The present study describes the potential use of 3D MnO2 nanofibrous mesh as photocatalyst for removal of organic dye. The MnO2 nanofibrous mesh has synthesized through facile, one-pot and cost-effective hydrothermal approach without using any template or other structure directing compounds. 3D MnO2 patterns clearly depict the well-dispersed nanofibers having diameter in the range of 10-25 nm, and several microns in length; the unique mesh morphology offers a large surface area to promote enhanced photocatalytic activity, and also provided a macro porous network that supported efficient oxidation. Moreover, the strong electronic cloud and high aspect ratio (HAR) MnO2 nanofibers facilitated the fast oxidation of dyes molecule in a very short period of time. The designed nanostructured material was found to possess heterogeneous photocatalytic potential against the oxidative degradation of Crystal Violet (CV) dye taken as model pollutant. The photocatalytic performance of these materials was evaluated under ultra-violet as well as visible light. Best photocatalytic performance was achieved under visible light with almost complete degradation (97%) exhibited within 90 min of irradiation time. Furthermore, the degradation efficiency of prepared photocatalyst was determined in presence and absence of initiator, hydrogen peroxide, and under different pH conditions. Finally, this technique can be easily scaled-up for removal of various polycyclic organic wastes that might be of potential industrial and environmental interests. (C) 2019 The Authors. Published by Elsevier B.V.