Photocatalytic oxidation of water and air contaminants with metal doped BiTaO4 irradiated with visible light

A review of volatile organic compounds (VOCs) degradation by vacuum ultraviolet (VUV) catalytic oxidation

Volatile organic compounds (VOCs), one of the most important gaseous air pollutants, are getting more and more attention, and a lot of technologies have been studied and applied to eliminate VOCs emissions. Advanced oxidation processes (AOPs) are considered as one of the most promising techniques used for the degradation of VOCs. Vacuum ultraviolet (VUV) catalytic oxidation system is a typical composite AOPs system involving several processes such as VUV photodegradation, photocatalytic oxidation (PCO), ozone catalytic oxidation (OZCO) and their combinations. VUV based catalytic oxidation processes have been intensively studied for degrading VOCs. This review summarizes the recent studies on the use of VUV catalytic oxidation for degrading VOCs. All the processes involved in VUV catalytic oxidation and their combinations have been reviewed. Studies of VOCs degradation by VUV catalytic oxidation can be generally divided into two aspects: developments of catalysts and mechanistic studies. Principles of different processes, strategies of catalyst development and reaction mechanism are summarized in this review. Two directions of prospective future work were also proposed.

Construction of novel Z-scheme Ag/ZnFe2O4/Ag/BiTa1-xVxO4 system with enhanced electron transfer capacity for visible light photocatalytic degradation of sulfanilamide

A novel Z-scheme system, Ag/ZnFe₂O₄/Ag/BiTa_1-xV_xO₄ with enhanced electron transfer capacity was constructed for degrading sulfanilamide (SAM) using solar light. The photocatalytic activity of Ag/ZnFe₂O₄/Ag/BiTa_1-xV_xO₄ was investigated. The effects of the mass ratio (ZnFe₂O₄:BiTaO₄), doped V dose, Ag wt.% content, and irradiation time on the catalytic performance were evaluated. The reasonable mechanism of Ag/ZnFe₂O₄/Ag/BiTa_1-xV_xO₄ solar photocatalytic degradation was also presented. These results reveal Ag/ZnFe₂O₄/Ag/BiTa_1-xV_xO₄ possesses enhanced photocatalytic performance. The loaded Ag as electron mediator increases the electron transfer rate. Particularly, the doped V and the Fe ions from ZnFe₂O₄ form a powerful electron driving force, which enhances the electron transfer capacity. Ag/ZnFe₂O₄/Ag/BiTa_1-xV_xO₄ shows optimal photocatalytic performance at 2.0 wt.% Ag and 0.5% doped V dose (ZnFe₂O₄:BiTaO₄ = 1.0:0.5). Also, Ag/ZnFe₂O₄/Ag/BiTa_1-xV_xO₄ exhibits high stability and repeatability in photocatalytic degradation. Several active species (^•OH, ^•O₂^-, and h⁺) are produced in the Z-scheme photodegradation of SAM. These results on the enhanced photocatalytic activity of Ag/ZnFe₂O₄/Ag/BiTa_1-xV_xO₄ are ascribed to synergistic photocatalytic effects of ZnFe₂O₄ and BiTa_1-xV_xO₄ mediated through Ag and driven by doped V and Fe ions. Therefore, the Z-scheme Ag/ZnFe₂O₄/Ag/BiTa_1-xV_xO₄ photocatalytic technology proves to be promising for the solar photocatalytic treatment of antibiotics under solar light.

Recent advances in non-metal modification of graphitic carbon nitride for photocatalysis: a historic review

This review provides a comprehensive survey and critical comments on the development of photocatalysts with a focus on the metal-free materials.

The Polymerization Effect on Synthesis and Visible-Light Photocatalytic Properties of Low-Temperature β-BiNbO4 Using Nb-Citrate Precursor

Low-temperature β-BiNbO4 powders (denoted as Low-β) were prepared by citrate and Pechini methods using homemade water-soluble niobium precursors. The addition of ethylene glycol and the resultant polymerization effect on the synthesis and visible-light photocatalytic performance of β-BiNbO4 powders were fully investigated. The polymerization effect is beneficial to lower the phase formation temperature and obtain smaller particle catalysts. Both methods can synthesize catalysts with excellent performance of visible-light degradation of methyl violet (MV). The Low-β BiNbO4 powder prepared by citrate method shows better degradation rate of about 1 h to decompose 80 % of MV and also displays good photocatalytic stability. The photodegradation of MV under the visible-light irradiation followed the pseudo-first-order kinetics according to the Langmuir-Hinshelwood model, and the obtained first-order rate constant and half-time are 2.85 × 10(-2) min(-1) and 24.3 min, respectively. The better photocatalytic performance of BiNbO4 powders prepared by citrate method can be attributed to its smaller band gap and better crystallinity.

Tailoring the electronic structure of β-Ga2O3 by non-metal doping from hybrid density functional theory calculations

Se-doped and I-doped β-Ga₂O₃ are theoretically found to be promising photocatalysts for water splitting in the visible region.