Synergetic Removal of Cr(Vi) and Dibutyl Phthalate Mixed Pollutants on Mos2 Sheet Inserted in Tio2 Nanotube Under Visible Light

Abstract

Molybdenum sulfide (MoS2) sheet inserted in porous-walled titanium dioxide nanotube arrays (TNTAs) with Z-scheme heterojunctions were synthesized via anodic oxidation and hydrothermal methods. A series of characterizations and evaluations were performed to study the removal of combined contamination in wastewater by MoS2@p-TNTAs under visible light. The MoS2@p-TNTAs exhibits a robust response to visible light, with a large specific surface area and high crystallinity. Furthermore, the composites maintained a stable porous-walled nanotube array structure with tight inter-semiconductor bonding after compounding. The degradation efficiency of MoS2@p-TNTAs has been maintained above 85% after 20 cycles, while the morphological structure remained stable, demonstrating outstanding structural stability and reusability. These composites showed superior removal efficiency compared to treating single pollutants when synergistically treating the Cr(VI)-DBP mixed pollution. The degradation kinetic constants of Cr(VI) and DBP in the mixed pollution were 8.3 and 3.3 times higher than those of single pollution, respectively. This can be attribute to Cr(VI) acts as an electron-trapping agent to be reduced, and DBP acts as a hole-trapping agent to be oxidized so that the electron-hole pairs can be fully utilized to improve the photocatalytic reaction efficiency and realize the synergistic treatment of the mixed contamination.

Keywords: Porous structure, TiO2 nanotube arrays, MoS2 sheet, Photocatalytic