Efficient Photocatalytic Removal of Contaminant by Bi₃Nb_xTa_1−xO₇ Nanoparticles under Visible Light Irradiation

Abstract

Nanosized Bi 3 Nb x Ta 1-x O 7 photocatalysts were prepared by a facile and low-cost sol-gel method using stable, less toxic Ta 2 O 5 , Nb 2 O 5 , and Bi(NO 3 ) 3 • 5H 2 O as the raw materials. The as-prepared samples were characterized by X-ray diffraction, transmission electron microscopy, Fourier transformation infrared spectroscopy, X-ray photoelectron spectroscopy, and UV-vis diffuse reflectance spectroscopy. The Bi 3 Nb x Ta 1-x O 7 nanoparticles exhibited an efficient photocatalytic activity in the decomposition of acid red G (ARG) dye solution under visible light irradiation. Besides decoloring, the typical sample Bi 3 Nb 0.6 Ta 0.4 O 7 also showed an excellent photocatalytic property for the removal of the cyanotoxin, microcystin-LR (MC-LR, an emerging contaminant from the Contaminant Candidate Lists (CCLs 1-3) of the USEPA). The excellent visible light photocatalytic activity of the samples was mainly attributed to their narrow band gaps, small particle size, and the oxygen vacancies on the surface of the catalysts. According to experimental results, a possible mechanism of the photocatalysis over Bi 3 Nb x Ta 1-x O 7 was proposed.

Single-crystalline Bi5O7NO3 nanofibers: Hydrothermal synthesis, characterization, growth mechanism, and photocatalytic properties

“…Accelerated separation of electron-hole pairs upon photoexcitation was ascribed to the permanent static electric fields between the Bi 5 O 7 and N-O 3 layers. When the aqueous RhB/Bi 5 O 7 NO 3 suspension was irradiated with visible light, the electron-hole pairs react with O 2 and OH -directly or indirectly to form O ÅÀ 2 and Å OH oxidation species [22,49,50]. Terephthalic acid photoluminescence (TA-PL) probing technique has been widely used in the detection of Å OH radicals [47,51].…”

Synthesis of nanometer-size Bi3TaO7 and its visible-light photocatalytic activity for the degradation of a 4BS dye

“…For instance, tantalum alkoxides are expensive, they need special care such as the use of dry solvents and inert atmospheres, and can produce polluting side products; the use of tantalum chloride produces toxic HCl gas during the synthesis process. Therefore, it is important to synthesize new nanosized tantalate photocatalysts with high visible-light photocatalytic activity via a facile and low-cost sol-gel method [26].…”

Multi-layer three-dimensionally ordered Bismuth trioxide/Titanium dioxide nanocomposite: Synthesis and enhanced photocatalytic activity

“…Fig. 3(b) presents the Bi 4f XPS spectra of the 3DOM Bi 2 O 3 /TiO 2 -X, which could be observed that two peaks for the Bi 4f of the 3DOM Bi 2 O 3 /TiO 2 -X are located at the binding energies of 159.6 and 164.8 eV [42,43], pertaining to Bi 4f 7/2 and Bi 4f 5/2 respectively. Moreover, there is with a spin-orbit splitting of 5.3 eV belonged to the characteristic of Bi 3+ [44].…”