Study of electronic and optical properties of BiTaO₄ for photocatalysis

Abstract

We present the optical absorption spectrum of BiTaO 4 using the photo acoustic spectroscopy (PAS) technique and first principles approach. Band gap have been estimated 2.65 and 2.45 eV using PAS method and DFT calculations, respectively. Position of reduction and oxidation level with respect to vacuum level are identified, which shows that BiTaO 4 can be used as photocatalyst for hydrogen production. Electronic structure is explained by plotting total density of states (TDOS).

Synthesis of CdS nano-spheres by a simple and fast sonochemical method at room temperature

“…As seen, as the amount of sulfur in starting solution increases a blue shift is observed as a consequence of the decrease in particle size (Table 1). To obtain the optical band gap energies, the geometrical method was applied to the experimental data, assuming direct band transitions [18], which uses the relation below:…”

Sonochemical synthesis of Cd1−xZnxS solid solutions for application in photocatalytic reforming of glycerol to produce hydrogen

“…To obtain the optical band gap energies, the geometrical method was applied to the DRS experimental data, assuming direct band transitions [28], which uses the relation below,…”

Visible-light-driven photocatalytic hydrogen production over dye-sensitized β-BiTaO4

“…These materials are envisaged as interesting photocatalysts for eliminating organic pollutants from domestic or industrial effluents [5], as well as for producing H 2 by the photocatalytic decomposition of water under UV light irradiation [6]. Recently, we prepared nano-sized triclinic BiTaO 4 (known as type ␤ polymorph, stable at high temperatures) by polymeric precursor method with BET surface area of 3.31 m 2 g −1 [7,8]. It is seven times much higher than surface area of BiTaO 4 obtained from solid state reaction.…”

“…The pH of zero point of charge (pHZPC) is given by one half of the sum of the two surface pK a s [9]. At high pH, under conditions in which the pH > pH ZPC , the metal oxide surface become negative ( MO − ) and the interactions with cationic dye will be favored, while anionic dye will be favored at low pH under conditions in which pH < pH ZPC , where the surface is positively charged ( MOH 2 + ).…”