Tailored MXene-derived nano-heterostructure oxides for peroxymonosulfate activation in the treatment of municipal wastewaters.

Nowadays, in the field of environmental protection, a huge effort is focused on efficient and sustainable processes to treat wastewaters. The current study emphasizes the photocatalytic performance of TiNbO, a nano-heterostructure material derived from the oxidation of (TiNb)CT MXene. The TiNbO nano-heterostructure exhibited remarkable performance in the degradation of caffeine (CAF) and sulfamethoxazole (SMX) under UVA irradiation in the presence of peroxymonosulfate (PMS).

MXene-Derived Oxide Nanoheterostructures for Photocatalytic Sulfamethoxazole Degradation.

Herein, we report for the first time the use of ternary oxide nanoheterostructure photocatalysts derived from (Nb , Ti )CT MXene in the treatment of water. Three different compositions of binary MXenes, viz., (TiNb)CT , (TiNb)CT , and (TiNb)CT (with T = OH, F, and Cl), were used as single-source precursor to produce TiNbO -3:1, TiNbO -1:1, and TiNbO -1:3 by controlled-atmosphere thermal oxidation.

2D TiO Nanosheets Decorated Via Sphere-Like BiVO: A Promising Non-Toxic Material for Liquid Phase Photocatalysis and Bacterial Eradication.

An in-depth investigation was conducted on a promising composite material (BiVO/TiO), focusing on its potential toxicity, photoinduced catalytic properties, as well as its antibiofilm and antimicrobial functionalities. The preparation process involved the synthesis of 2D TiO using the lyophilization method, which was subsequently functionalized with sphere-like BiVO through wet impregnation. Finally, we developed BiVO/TiO S-scheme heterojunctions which can greatly promote the separation of electron-hole pairs to achieve high photocatalytic performance.

Controversial mechanism of simultaneous photocatalysis and Fenton-based processes: additional effect or synergy?

Many published articles have reported the advantages of coupling photocatalysis and Fenton-based processes for environmental remediation purposes, especially wastewaters treatment, but without providing detailed discussion on how and why the resulting process is better, thus leading to misconception about their synergy. In this work, the context of the water pollution is presented along with the pros and cons of individual photocatalysis and Fenton-based processes. The simultaneous triggering of these two advanced oxidation processes is critically discussed from both performance and mechanism sides since additional effect and synergy are often misunderstood in the literature.

Application of MXene for remediation of low-level radioactive aqueous solutions contaminated with Ba and Cs.

MXene is an innovative multilayered material that has been prepared by an acid-salt (HCl + NHF) etching route and tested for the removal of Ba and Cs in radioactive conditions for the first time. MXene has exhibited high uptake capacity of about 154.9 and 121.

Versatile application of BiVO/TiO S-scheme photocatalyst: Photocatalytic CO and Cr(VI) reduction.

Herein, the synthesis, characterization, and reduction properties of 2D TiO aerogel powder decorated with BiVO (TiO/BiVO) were investigated for versatile applications. First, 2D TiO was prepared via lyophilization and subsequently modified with BiVO using a wet impregnation method. The morphology, structure, composition, and optical properties were evaluated using transmission electron microscopy (TEM), X-ray diffractometry (XRD), laser-induced breakdown spectroscopy (LIBS), and diffuse reflectance spectroscopy (DRS), respectively.

Anodic TiO Nanotube Layers for Wastewater and Air Treatments: Assessment of Performance Using Sulfamethoxazole Degradation and NO Reduction.

The preparation of anodic TiO nanotube layers has been performed using electrochemical anodization of Ti foil for 4 h at different voltages (from 0 V to 80 V). In addition, a TiO thin layer has been also prepared using the sol-gel method. All the photocatalysts have been characterized by XRD, SEM, and DRS to investigate the crystalline phase composition, the surface morphology, and the optical properties, respectively.

Fluoride-free synthesis of anodic TiO nanotube layers: a promising environmentally friendly method for efficient photocatalysts.

TiO nanotube (TNT) layers are generally prepared in fluoride-based electrolytes electrochemical anodization that relies on the field-assisted dissolution of Ti metal forming nanoporous/nanotubular structures. However, the usage of fluoride ions is considered hazardous to the environment. Therefore, we present an environmentally friendly synthesis and application of TNT layers prepared in fluoride-free nitrate-based electrolytes.

Contribution of photocatalytic and Fenton-based processes in nanotwin structured anodic TiO nanotube layers modified by Ce and V.

In the present work, nanotwin structured TiO nanotube (TNT) layers are prepared by the electrochemical anodization technique to form the anatase phase and by surface modification spin-coating of Ce and V precursors to form Ce-TNT and V-TNT, respectively. The surface and cross-sectional images by SEM revealed that the nanotubes have an average diameter of ∼130 nm and a length of ∼14 μm. In addition, the TEM images revealed the nanotwin structures of the nanotubes, especially the anatase (001) and (112) twin surfaces, that increase the transport of photogenerated charges.

Impacts of environmental levels of hydrogen peroxide and oxyanions on the redox activity of MnO particles.

Despite the widespread presence of hydrogen peroxide (HO) in surface water and groundwater systems, little is known about the impact of environmental levels of HO on the redox activity of minerals. Here we demonstrate that environmental concentrations of HO can alter the reactivity of birnessite-type manganese oxide, an earth-abundant functional material, and decrease its oxidative activity in natural systems across a wide range of pH values (4-8). The HO-induced reductive dissolution generates Mn(II) that will re-bind to MnO surfaces, thereby affecting the surface charge of MnO.

Significant role of iron on the fate and photodegradation of enrofloxacin.

Enrofloxacin (ENR) belongs to the fluoroquinolone (FQ) antibiotics family, which are contaminants of emerging concern frequently found in effluents. Although many works studying photo-Fenton process for FQ degradation have been reported, there are no reports analysing in deep the effect of iron complexation, as well as other metals, towards FQs' photolysis, which, evidently, also contributes in the overall degradation of the pollutant. Therefore, in this work, we report a comparative study between the photochemical fate of ENR and its complex with Fe(III) under simulated sunlight irradiation.

Phenanthrene decomposition in soil washing effluents using UVB activation of hydrogen peroxide and peroxydisulfate.

In this work, the decomposition of phenanthrene (PHE) in mimic and real soil washing (SW) effluents was investigated using UVB light assisted activation of hydrogen peroxide (HO) and peroxydisulfate (PDS) oxidation processes. The impact of oxidant concentration, initial pH, and coexisting inorganic anions (Cl, HCO and NO) on PHE removal was evaluated. PHE degradation efficiency under UVB irradiation followed the order of UVB/PDS > UVB/HO > UVB.

Ferrate(VI) oxidation of pentachlorophenol in water and soil.

Although the use of ferrate (VI), an emerging green oxidant, has been widely investigated to remove organic pollutants in water, its ability to remediate contaminated soils has been scarcely evaluated. Here, we explore the use of ferrate (VI) to degrade a polychlorinated persistent compound, the pentachlorophenol (PCP), in aqueous solution and in an aged contaminated soil under batch, water-saturated and water-unsaturated flow conditions. The first results showed the prominent efficiency of ferrate (VI) over conventional oxidants (e.

Innovative depollution treatment using multi-valent iron species: from fundamental study to application in municipal wastewater.

In this work, a new combination of oxidation treatments for the degradation of bisphenol A (BPA) is investigated. This innovative wastewater (WW) treatment includes the use of ferrate (FeO) and its decomposition byproducts under dark and UVA irradiation. The oxidation by ferrate leads to a fast but incomplete degradation of BPA with a degradation extent of 45% after 60 min under adopted experimental conditions.

Enhancement of iron-mediated activation of persulfate using catechin: From generation of reactive species to atenolol degradation in water.

Persulfate (PS) activation reaction, which forms sulfate radical (SO), can be used to degrade organic pollutants in water. However, a drawback of this reaction is that the regeneration of ferrous ions requires a high concentration of hydrogen peroxide (Fenton-like reaction) or use of UV radiation. Catechin (CAT), a non-toxic antioxidant of natural origin from tea, is used in this work to improve the sulfate radical-mediated degradation of atenolol (ATL, a model pollutant) in water using relatively low concentrations of reactive chemical species (less than 100 μM).

Bismuth vanadate-based semiconductor photocatalysts: a short critical review on the efficiency and the mechanism of photodegradation of organic pollutants.

The number of publications on photocatalytic bismuth vanadate-based materials is constantly increasing. Indeed, bismuth vanadate is gaining stronger interest in the photochemical community since it is a solar-driven photocatalyst. However, the efficiency of BiVO-based photocatalyst under sunlight is questionable: in most of the studies investigating the photodegradation of organic pollutants, only few works identify the by-products and evaluate the real efficiency of BiVO-based materials.