Enhanced Photocatalytic Activity of Hierarchical Macro-Mesoporous Anatase byZrO2Incorporation

Abstract

The effect of the addition of zirconia in the photocatalytic behaviour of titania is analysed. In order to increase the ways for reagent and product diffusion in the material, a sol-gel hydrothermal synthesis route using Tween-20 as a directing agent to obtain a hierarchical macro-mesoporous structure is proposed. Nanostructured macro-mesoporous TiO2/ZrO2photocatalyst with 0, 10, 20, 30, and 100% mol of ZrO2were obtained and calcined at different temperatures. The crystalline structure was analyzed by X-ray diffraction and TEM. The porosity was confirmed by SEM, TEM, and nitrogen adsorption-desorption isotherms. The worm-like mesoporous structure was confirmed by TEM. The specific surface areas obtained by Brunauer-Emmet-Teller method (BET) ranged from 125 to 180 m2/g. The Tween-20 total elimination from the structure by thermal treatment was confirmed by infrared spectroscopy and thermogravimetric analysis. Additionally, the photocatalytic effect of the zirconia addition was studied in the methylene blue (MB) degradation reaction, and the best photocatalytic activity was obtained in the sample with 10% mol of ZrO2, degrading up to 92% the MB.

Enhanced catalytic degradation of ciprofloxacin over Ce-doped OMS-2 microspheres

“…All the samples exhibited type IV isotherms, indicative of a solid mesoporous structure. Except for the difference that the isotherms of OMS-2 and Ce(0.06)-OMS-2 were with a H3 hysteresis loop associated with rod-like fibers given rise to narrow slit porous shape, while those of Ce(0.48)-OMS-2 and Ce(0.96)-OMS-2 were with a H2 hysteresis loop corresponding to pores with narrow necks and wider bodies [23]. The BET surface area followed the order of OMS-2 (72 m 2 g −1 ) < Ce(0.06)-OMS-2 (90 m 2 g −1 ) < Ce(0.48)-OMS-2 (304 m 2 g −1 ) < Ce(0.96)-OMS-2 (366 m 2 g −1 ), indicating that the doping of Ce significantly increased the surface area, which was likely due to the reduction of fiber length with increase of Ce content.…”

Thermally treated zeolitic imidazolate framework-8 (ZIF-8) for visible light photocatalytic degradation of gaseous formaldehyde

“…[8][9][10] A hierarchical porous structure is more attractive owing to the facilitation of mass diffusion and the improved light transmittance. [11][12][13] Therefore, a porous photocatalyst is desirable for HCHO elimination.…”

Decolorization of Rhodamine B dye by using multiwalled carbon nanotubes/Co–Ti oxides nanocomposite and Co–Ti oxides as photocatalysts

“…The active surface area and adsorption capacity in this system are greatly increased to the dye molecules (Smirnova et al 2015). Various metal oxides such as ZnO, Al 2 O 3 , MnO 2 , ZrO 2 , Ta 2 O 5 and In 2 O 3 have been coupled with TiO 2 and were found to be efficiently increased its photocatalytic activity (Benjume et al 2012).…”

“…It is chemically and biologically inert, non-corrosive, photocatalytically stable and has high oxidative ability (Kerkez and Boz 2015). TiO 2 represents low photocatalytic activity due to its wide band gap, high electron-hole pair recombination rate and also its excitation only under UV light wavelength (Benjume et al 2012). Various approaches have been practiced to retard its charge recombining deficiency such as depositing noble metals like Pt or Pd on TiO 2 surface , doping other metal such as magnesium on TiO 2 surface (Avasarala et al 2016) and combining TiO 2 with other metal oxides such as ZrO 2 to form nanoconjugates (Benjume et al 2012).…”

“…TiO 2 represents low photocatalytic activity due to its wide band gap, high electron-hole pair recombination rate and also its excitation only under UV light wavelength (Benjume et al 2012). Various approaches have been practiced to retard its charge recombining deficiency such as depositing noble metals like Pt or Pd on TiO 2 surface , doping other metal such as magnesium on TiO 2 surface (Avasarala et al 2016) and combining TiO 2 with other metal oxides such as ZrO 2 to form nanoconjugates (Benjume et al 2012). Nanoconjugates also called mixed oxide composites have more efficient photocatalytic activity than pure substances through the generation of new active sites, thermal stability, improved mechanical strength and surface area of titania.…”