Photocatalytic Activity of Combustion Synthesized ZrO₂ and ZrO₂–TiO₂ Mixed Oxides

Abstract

Tetragonal ZrO 2 , synthesized by solution combustion technique, was found to be photocatalytically active for the degradation of anionic dyes. The compound was characterized by FT-Raman spectroscopy, X-ray photoelectron spectroscopy, FT-infrared spectroscopy, UVÀvis spectroscopy, BET surface area analysis, and zero point charge pH measurement. A high concentration of surface hydroxyl groups was observed over the catalyst, as confirmed by XPS and FTIR. The photocatalytic degradation of orange G, amido black, remazol brilliant blue R, and alizarin cyanine green (ACG) was carried out with this material. The effect of pH, inorganic salts, and H 2 O 2 on the activity of the catalyst was also studied, and it was found that the catalyst maintained its activity at a wide range of pH and in the presence of inorganic salts. Having established that ZrO 2 was photocatalytically active, mixed oxide catalysts of TiO 2 ÀZrO 2 were also tested for the photocatalytic degradation of ACG, and the 50% ZrO 2 ÀTiO 2 mixed oxides showed activity that was comparable to the activity of TiO 2 .

Synthesis, luminescence and photocatalyst properties of zirconia nanosheets by modified Pechini method

“…The photocatalytic degradation of anionic dye such as methyl orange was carried out by t-ZrO 2 nanopowdersat optimized conditions (C 0 of dyes= 10 ppm and 25 mg nanopowders) and different pH (Fig. 7).Literatures show that the isoelectric point (pH ie ) of zirconia was4.1 for t-ZrO 2 sample [56][57][58][59][60]. At pH lower than pH ie , the surface oftzirconia are positive and at pH higher than pH pzc, the surface of nanostructures are negative.…”

Study on crystallinity and morphology controlling of titania using acrylamide gel method and their photocatalytic properties

“…The kinetics of photocatalytic degradation of dyes has been reported to usually follow pseudofirstorder kinetics [42]:…”

“…Thus the plot of variation of natural log of the normalized concentration with time will be linear, and the slope of the regressed line will yield the rate coefficient of degradation [42].…”

Zirconia nanoparticle-modified graphitic carbon nitride nanosheets for effective photocatalytic degradation of 4-nitrophenol in water

“…Sensitization and combination with semiconductor NPs (namely Au, Ag, Pt, and Pd) and carbon-based materials (CNTs and graphene) are the most viable routes for improving the g-C 3 N 4 -based photocatalysts (Sridharan et al 2014). Among the metal oxide NPs, ZrO 2 is a material with favored properties including high stability, high toughness, high chemical strength, desirable corrosion, chemical and microbial resistance (Polisetti et al 2011;Singh and Nakate 2014). Moreover, ZrO 2 NPs have plenty of oxygen vacancies on surfaces with wideband-gap P-type semiconductors.…”