WITHDRAWN: Enhanced Visible-Light Promoted Photocatalytic Activity of Mn3O4-based Photocatalysts in Removal of Methylene Blue

Abstract

In the present work, pure Mn3O4, Zirconium (Zr)-doped Mn3O4 and Samarium(Sm)-doped Mn3O4 were synthesized by the ultrasonic assisted co-precipitation method. In another step, zeolite 4A was prepared using a natural zeolite (clinoptilolite) by hydrothermal method. Subsequently, the synthesized zeolite 4A was utilized as an efficient support for immobilization of some of the obtained Mn3O4-based photocatalysts, thereby, nanocomposites of Mn(3-x) SmxO4 (x= 0.02)/Zeolite 4A and Mn(3-x) ZrxO4 (x= 0.02)/Zeolite 4A were synthesized. The characterization of the products was performed by exploiting X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDX) and Diffuse Reflectance Spectroscopy analysis (DRS). The XRD patterns of the doped Mn3O4samples confirmed the formation of Hausmannite structure without any other impurities. By increasing of dopant content in the structure of Mn3O4, a small shift towards lower diffraction angles and a decreased intensity of the peaks in XRD patterns were detected validating the incorporation of dopant ions. Finally, methylene blue (MB) aqueous solution as an organic pollutant was used to study the photocatalytic performance of synthesized photocatalysts. Regarding the results, Mn(3-x) SmxO4 (x= 0.02)/Zeolite 4A nanocomposite and Mn(3-x) ZrxO4 (x= 0.1) nanoparticles exhibited the remarkable photocatalytic efficiency of 95. 5% and 98.4% in MB degradation process, respectively.

Experimental correlation of Mn3+cation defects and electrocatalytic activity of α-MnO2– an X-ray photoelectron spectroscopy study

“…S31 †), [189][190][191][192][193][194][195] an orthorhombic spinel phase (ICDD PDF 00-024-0508, space group Pcab, a ¼ 9.4161 Å, b ¼ 9.4237 Å, c ¼ 9.4051 Å) [196][197][198] for Mn 2 O 3 (Fig. S32 †) and a tetragonal spinel phase (ICDD PDF 00-024-0734, space group I41/amd, a ¼ b ¼ 5.7621, c ¼ 9.4696) [199][200][201] for Mn 3 O 4 (Fig. S33 †).…”