The Structural, Photocatalytic Property Characterization and Enhanced Photocatalytic Activities of Novel Photocatalysts Bi2GaSbO7 and Bi2InSbO7 during Visible Light Irradiation

Abstract

In order to develop original and efficient visible light response photocatalysts for degrading organic pollutants in wastewater, new photocatalysts Bi2GaSbO7 and Bi2InSbO7 were firstly synthesized by a solid-state reaction method and their chemical, physical and structural properties were characterized. Bi2GaSbO7 and Bi2InSbO7 were crystallized with a pyrochlore-type structure and the lattice parameter of Bi2GaSbO7 or Bi2InSbO7 was 10.356497 Å or 10.666031 Å. The band gap of Bi2GaSbO7 or Bi2InSbO7 was estimated to be 2.59 eV or 2.54 eV. Compared with nitrogen doped TiO2, Bi2GaSbO7 and Bi2InSbO7, both showed excellent photocatalytic activities for degrading methylene blue during visible light irradiation due to their narrower band gaps and higher crystallization perfection. Bi2GaSbO7 showed higher catalytic activity compared with Bi2InSbO7. The photocatalytic degradation of methylene blue followed by the first-order reaction kinetics and the first-order rate constant was 0.01470 min−1, 0.00967 min−1 or 0.00259 min−1 with Bi2GaSbO7, Bi2InSbO7 or nitrogen doped TiO2 as a catalyst. The evolution of CO2 and the removal of total organic carbon were successfully measured and these results indicated continuous mineralization of methylene blue during the photocatalytic process. The possible degradation scheme and pathway of methylene blue was also analyzed. Bi2GaSbO7 and Bi2InSbO7 photocatalysts both had great potential to purify textile industry wastewater.

Photophysical and Photocatalytic Properties of BiSnSbO6 under Visible Light Irradiation

“…As shown in Figure 7 b,c, the calculational k value of BiSnSbO 6 for the phenol photodegradation was higher than that of N-doped TiO 2 . Above results demonstrated that the photosensitive effect was not a main factor in the photodegradation process of RhB with BiSnSbO 6 as a photocatalyst and BiSnSbO 6 itself had photocatalytic activity [ 54 , 55 ].…”

Enhanced Visible Light Sensitization of N-Doped TiO2 Nanotubes Containing Ti-Oxynitride Species Fabricated via Electrochemical Anodization of Titanium Nitride

“…Zero-order kinetic models are typical of reactions where the surface of active sites is quickly saturated and mass diffusion, rather than the concentration of reactive species, becomes the controlling stage. , The fastest degradation rate was assigned to a 4.1 atom % N loading, presenting a kinetic constant of 1.9 × 10 –3 min –1 , whereas the rate became progressively slower upon the addition of further N doping. Compared to N-doped TiO 2 NPs, the kinetic constant was of the same order of N-doped TiO 2 fabricated by the sol–gel method . Furthermore, TiO 2 –N containing 4.1 atom % of N presented a slightly superior kinetic constant than N-doped sputtered TiO 2 films presenting N concentration of 1.2 atom % .…”

“…Compared to N-doped TiO 2 NPs, the kinetic constant was of the same order of N-doped TiO 2 fabricated by the sol−gel method. 104 Furthermore, TiO 2 −N containing 4.1 atom % of N presented a slightly superior kinetic constant than N-doped sputtered TiO 2 films presenting N concentration of 1.2 atom %. 31 Interestingly, TiO 2 nanospheres containing TiO 1−x N x could lead to the fastest degradation of MB by nitriding TiO 2 nanosphere for at least 7 h at 700 °C.…”

Synthesis, Performance Measurement of Bi2SmSbO7/ZnBiYO4 Heterojunction Photocatalyst and Photocatalytic Degradation of Direct Orange within Dye Wastewater under Visible Light Irradiation

“…The conventional processing methods that we used to degrade those dye contaminates were bio-degradation, electrochemistry, adsorption and flocculation-precipitation [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. However, because of the shortcomings and limitations of each method, the conventional methods of treating wastewater cannot achieve the maximum degradation effect [ 23 ]. Since 1972, photocatalytic reaction was firstly found, the photocatalysis technology had been booming due to the strong market demand [ 24 ], and is widely used in sewage treatment [ 25 , 26 ].…”