The Effects of Manganese Dopant Content and Calcination Temperature on Properties of Titania-Zirconia Composite

Abstract

The effects of dopant content and calcination temperature on Mn-doped TiO2-ZrO2 structure and properties were successfully investigated. Composite of Mn-doped titania-zirconia was synthesized by sol-gel method. Titanium(IV) isopropoxide was used as the precursor of TiO2, while zirconiapowder was used as another semiconductor. MnCl2∙4H2O was used as the source of dopant in this study. Various amounts of manganese were incorporated into TiO2-ZrO2 and calcination was performed at temperatures of 500, 700 and 900 °C. Synthesized composites were characterized by Fourier-transform infrared spectroscopy (FTIR), specular reflectance UV-Vis spectroscopy (SR UV-Vis), X-ray diffraction method (XRD) and scanning electron microscopy equipped with X-ray energy dispersive spectroscopy (SEM-EDX). The results showed that Mn-doped TiO2-ZrO2 with the lowest bandgap (2.78 eV) was achieved with 5% of Mn dopant and calcined at 900 °C, while Mn-doped TiO2-ZrO2 with the highest bandgap (3.12 eV) was achieved with 1% of Mn dopant content calcined at 500 °C.

Visible-Light-Induced Photodegradation of Methylene Blue Using Mn,N-codoped ZrTiO₄ as Photocatalyst

“…An absorption spectrum at 1441 cm −1 region indicates the presence of Mn dopant in the composites [34]. At the low wavenumber region, the absorption belonged to the vibration of Ti-O-Ti, Mn-O-Ti, and Mn-O are found around 400-700 cm −1 [35]. Sharp peaks observed around 500 cm −1 correspond to the stretching vibration of Zr-O of the ZrO 2 phase [36].…”

Photodegradation of Phenol under Visible Light Irradiation Using Cu-N-codoped ZrTiO₄ Composite as a High-Performance Photocatalyst

“…Crystallization from amorphous to anatase is inhibited by the presence of copper and nitrogen dopants [42]. The presence of Zr 4+ in the TiO 2 system also inhibits the transformation of anatase to rutile [22] respectively. This is because ZrO 2 and N dopants prevent the transformation of anatase to rutile [43].…”

“…This coupling will offer the added benefits of large surface area, high thermal stability, and corrosion resistance [20]. Doping of ZrTiO 4 with metals, such as Fe [21], Mn [22], and Zn [23], as well as non-metals such as N [24] and C [25], has been reported to decrease the band gap to visible light. Copper (Cu) and nitrogen (N) have been chosen as the dopants for this work, as they both have excellent efficiency in separating the charge carriers.…”

Copper-and-Nitrogen-Codoped Zirconium Titanate (Cu-N-ZrTiO₄) as a Photocatalyst for Photo-Degradation of Methylene Blue under Visible-Light Irradiation

“…This is due to the heterojunction between the valence band and conduction band of ZrO 2 with TiO 2 [24]. The wide bandgap (E g ) of ZrO 2 mixes with the relatively small Eg of TiO 2 until it reaches equilibrium, resulting in a ZrTiO 4 band gap with a slightly smaller Eg [27]. Codoping of both nitrogen and copper shifts the absorption edge of the ZrTiO 4 composite towards the visible light region until it reaches the saturation point [31].…”

“…Zirconium titanate (ZrTiO 4 ) modified by the doping method will decrease the band gap to visible light. Several studies have reported that doping can be done with metals such as Fe [26], Mn [27], and Zn [28] and also non-metals such as N [29] and C [30]. In this study, copper (Cu) and nitrogen (N) were chosen as dopants because they have good charge-carrier separation efficiency.…”