Himanshu Narayan

Synthesis and characterization of Y3+-doped TiO2 nanocomposites for photocatalytic applications

The TiO(2).[Y(2)O(3)](x) (x = 0.1-0.4) nanocomposites (NCs) with an average particle size of 74 nm were prepared by the method of chemical co-precipitation followed by hydrolysis (CPH). Their visible light photocatalytic activity was investigated for the degradation of congo red (CR) dye. All NCs showed improved degradation as compared to the polycrystalline samples of similar compositions prepared by the solid-state reaction (SSR) route (average particle size of a few micrometers), as well as to the pure TiO(2). The better photocatalytic activity of the NCs was attributed to their smaller particle size. Another comparison of the results with those obtained with Zn(2+)/Fe(3+) ions co-doped TiO(2) NCs, under similar experimental conditions, revealed that in the Y(3+)-doped NCs, particle size might not be the only factor responsible for the improved photocatalytic properties. It was concluded that the Y(3+) ion-mediated suppression of the unwanted e(-)/h(+) recombination could be the possible factor leading to additional enhancement.

Visible Light Photocatalysis with Rare Earth Ion-Doped TiO Nanocomposites

Rare earth (R) ion-doped TiO2 nanocomposites (NCs) with general composition [R2O3]𝑥⋅[TiO2]1−𝑥 (R: Y, Yb, Gd; 𝑥=0.1, 0.2) were synthesized through co-precipitation/hydrolysis (CPH). NC particles with average size of approximately a few tens of nm were obtained. Similar compositions of polycrystalline (PC) samples with larger particle size were also prepared employing solid state reaction (SSR) method. Visible light photocatalytic activity of all samples was investigated for degradation of Congo red (CR) dye. Both in terms of apparent rate constant (𝑘obs) and percent degradation after 180 min (𝐶180), all NCs produced significantly enhanced degradation as compared to pure TiO2 and PC samples. Best degradation of 95% (𝐶180 value) resulted with 𝑥=0.2 composition of Y3