Design and Application of Ag₃PO₄@Ag₄V₂O₇ Z-Scheme Photocatalysts with a Micro-Nano Tube-Cluster Structure for the Co-Degradation of Nitrate and Ammonia in Wastewater

Abstract

Water eutrophication due to the discharge of nitrogen-containing wastewater has aroused widespread concern around the world, and photocatalysis is confirmed a promising method to dispose the problem. Nonetheless, co-degradation of ammonia nitrogen and nitrate nitrogen is still nerve-wracking. In this work, the Ag3PO4@Ag4V2O7 Z-scheme photocatalysts with a micro-nano tube-cluster structure were designed by a facile in situ growth method, which realized concurrent removal of nitrate and ammonia in wastewater, without the addition of hole scavengers or electron scavengers, due to its high redox ability. The experimental results demonstrated that P@V1 composites showed superior rate (2.79 times enhancement) and higher conversion (3.00 times enhancement) compared with the pure Ag4V2O7 crystals for ammonia degradation and the pure Ag3PO4 crystals for nitrate reduction, respectively. Therefore, Z-scheme photocatalysts offer a new thought for co-degradation of low concentrations of nitrogenous contaminated water.

ZnO Photocatalyst Revisited: Effective Photocatalytic Degradation of Emerging Contaminants Using S-Doped ZnO Nanoparticles under Visible Light Radiation

“…Various types of biological, physical, and chemical methods such as chemical deposition, separation, clotting, removal by adsorption on activated carbon, chlorination, and ozonation are applied to treat industrial wastewaters. − In the chemical methods, chlorination and ozonation are employed, which are slow processes, and they are not economically feasible; hence, the use of these approaches is limited. − The traditional filtration methods do not have good efficiencies and only cause phase changes of pollutants. The first studies on photocatalysts date back to 1970s when Fujishima and Honda realized the photocatalytic effects of TiO 2 electrodes on water decomposition into H 2 and O 2 . , In the last few decades, advanced oxidation processes (AOPs) have been proposed as successors to previous methods as they have greatly improved the degradation of organic pollutants. − The main feature of all AOPs is the production of highly reactive hydroxyl radicals with an oxidative power which is much faster than that of ozone and hydrogen peroxide. Recently, AOPs have mostly been replaced by some previously applied water treatment methods because they have strongly succeeded in the degradation of organic pollutants. , Oxidation in AOPs can be either homogeneous or heterogeneous .…”

Inside‐and‐Out Semiconductor Engineering for CO2 Photoreduction: From Recent Advances to New Trends

“…In contrast, the morphology control, such as 1D nanobelts, [ 383–387 ] or 2D nanosheets, [ 222,388–390 ] was introduced to enhance the photocatalytic activity of Z‐scheme junction photocatalysts. To build a unique 3D morphology, Yang et al [ 227 ] assembled 2D ZnIn 2 S 4 nanosheets onto 1D TiO 2 nanobelts to form a direct Z‐scheme junction ZnIn 2 S 4 /TiO 2 .…”

A novel 2D graphene oxide modified α-AgVO3 nanorods: Design, fabrication, and enhanced visible-light photocatalytic performance

“…Silver vanadium oxides (SVOs), including AgVO 3 [11], Ag 4 V 2 O 7 [12], Ag 3 VO 4 [13], and Ag 2 V 4 O 11 [14], have been widely exploited in the field of catalysis www.springer.com/journal/40145 owing to their excellent electrical properties, controllable surface, and easy availability. Among these SVOs, monoclinic structured α-AgVO 3 is one of the most promising visible-light-responsible photocatalyst because the hybridization of V 3d, O 2p, and Ag 4d orbits can form highly dispersed valence bands with a narrow bandgap [15].…”