Egg-shaped core/shell α-Mn2O3@α-MnO2 as heterogeneous catalysts for decomposition of phenolics in aqueous solutions

Document Type

Journal Article

Publication Title

Chemosphere

Publisher

Elsevier

School

School of Engineering

RAS ID

22074

Comments

Saputra, E., Zhang, H., Liu, Q., Sun, H., & Wang, S. (2016). Egg-shaped core/shell α-Mn 2 O 3@ α-MnO 2 as heterogeneous catalysts for decomposition of phenolics in aqueous solutions. Chemosphere, 159, 351-358. Available here

Abstract

Novel uniform ellipsoid α-Mn2O3@α-MnO2 core/shell (McMs) nanocomposites were prepared via a hydrothermal process with a shape-control protocol followed by calcination at different temperatures. The properties of the composites were characterized by a number of techniques such as thermogravimetric analysis (TGA), X-ray diffraction (XRD), N2 adsorption, and scanning electron microscopy (SEM). The core/shell materials were much effective in heterogeneous oxone® activation to generate sulfate and hydroxyl radicals for degradation of aqueous phenol. The McMs composites demonstrated catalytic activity for 100% phenol decomposition in short duration varying between 20 and 120 min, much higher than that of homogeneous Mn2+ system with 95% phenol degradation in 120 min. They also showed a higher activity than single-phase α-Mn2O3 or α-MnO2. The catalytic activity of phenol degradation depends on temperature, oxone® concentration, phenol concentration, and catalyst loading. The catalysts also showed a stable activity in several cycles. Kinetic study demonstrated that phenol degradation reactions follow a first order reaction on McMs catalysts giving activation energies at 32.1–68.8 kJ/mol. With the detection of radicals by electron paramagnetic resonance (EPR), the generation mechanism was proposed. © 2016 Elsevier Ltd

DOI

10.1016/j.chemosphere.2016.06.021

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