Enhanced hydrogen production under a visible light source and dye degradation under natural sunlight using nanostructured doped zinc orthotitanates

Abstract

Nanostructured zinc orthotitanates were successfully employed as solar light driven photocatalysts for waste degradation such as H2S which produces H2, a clean energy source, and dye degradation.

Synthesis Temperature Dependent Morphological Evolution in Zinc Titanate Heteronanostructures and Their Application in Environmental Remediation

“…The samples ZT‐150 (500), ZT‐180 (500) and ZT‐200 (500) show two band gaps; first in the range 3.3 eV to 3.5 eV and the second around 3.2 eV. The first band gap (3.3 eV to 3.5 eV) is attributed to the presence of cubic Zn 2 TiO 4 and the second band gap around 3.2 eV is attributed to the presence of tetragonal Zn 2 TiO 4 ,. Nikam et al have reported two band gaps in Zn 2 TiO 4 ; first one around 3.7 eV attributed to the presence of cubic Zn 2 TiO 4 and the second one at about 3.22 eV due to tetragonal Zn 2 TiO 4 .…”

“…The first band gap (3.3 eV to 3.5 eV) is attributed to the presence of cubic Zn 2 TiO 4 and the second band gap around 3.2 eV is attributed to the presence of tetragonal Zn 2 TiO 4 ,. Nikam et al have reported two band gaps in Zn 2 TiO 4 ; first one around 3.7 eV attributed to the presence of cubic Zn 2 TiO 4 and the second one at about 3.22 eV due to tetragonal Zn 2 TiO 4 . The band gap values for bulk cubic ZnTiO 3 and bulk cubic Zn 2 TiO 4 are 3.8 and 3.7 eV, respectively .…”

“…In addition, ZT‐150 (500) shows peaks due to ZnTiO 3 . Tetragonal Zn 2 TiO 4 is stable up to 550 °C and possesses the formula [Ti 0.92 Zn 0.08 ][Zn 1.92 Ti 0.08 ]O 4 . After calcination at 700 °C, the samples ZT‐RT (700), ZT‐50 (700) and ZT‐100 (700) show XRD peaks (Figure ) due to cubic ZnTiO 3 (JCPDS file no.…”

“…The samples calcined at 500 °C and consisting of particles with rod‐like morphology, ZT‐RT (500), ZT‐50 (500) and ZT‐100 (500), show emission bands at around 367 nm and 470 nm. The emission band at about 367 nm is attributed to surface oxygen vacancies occupied by single electrons while the emission band at about 470 nm is attributed to the presence of unoccupied oxygen vacancies on the surface (Scheme ) ,…”

“…Zn 2 Ti 3 O 8 possesses defect spinel structure with a band gap of 3.56 eV and it is stable up to 800 °C . Zinc titanates have been synthesized using ball milling, combustion method, polymeric precursor method, Rf magnetron sputtering, sol‐gel process,, molten salt method, atomic layer deposition, ethylene glycol mediated route, etc. There are a few reports on the synthesis of morphologically interesting zinc titanates ,,…”