Upconverting particles in near-infrared light-induced TiO photocatalysis: towards the optimal architecture of upconverter/photocatalyst systems.

Preparation of highly active core-shell/hybrid materials based on up-converting particles combined with semiconductors for photocatalytic application usually requires sophisticated and multi-step synthesis procedures. We propose a new design of a highly efficient NIR-driven photocatalytic system composed of spatially separated thin films of upconverting NaYF:Yb,Tm particles (UCPs), and TiO. Several samples of UCPs were prepared in the form of thin films and suspensions, directly coated with a titania layer or mixed with P25.

Functionalization of Polypropylene by TiO Photocatalytic Nanoparticles: On the Importance of the Surface Oxygen Plasma Treatment.

A new two-step method for developing a nanocomposite of polypropylene (PP) decorated with photocatalytically active TiO nanoparticles (nTiO) is proposed. This method involves the low-temperature plasma functionalization of polypropylene followed by the ultrasound-assisted anchoring of nTiO. The nanoparticles, polymeric substrate, and resultant nanocomposite were thoroughly characterized using nanoparticle tracking analysis (NTA), microscopic observations (SEM, TEM, and EDX), spectroscopic investigations (XPS and FTIR), thermogravimetric analysis (TG/DTA), and water contact angle (WCA) measurements.

Photocatalytic Transformation of Organics to Valuable Chemicals - Quo Vadis?

Recent development in photocatalysis is increasingly focused on transforming organic compounds toward producing fine chemicals. Simple, non-selective oxidation reactions (degradation of pollutants) and very demanding solar-to-chemical energy conversion processes (production of solar fuels) face severe economic limitations influenced by still low efficiency and insufficient stability of the systems. Synthesis of fine chemicals, including reductive and oxidative selective transformations, as well as C-C and C-N coupling reactions, can utilise the power of photocatalysis.

Water disinfection using hydrogen peroxide with fixed bed hematite catalyst - kinetic and activity studies.

A lab-scale reactor with a fixed-bed hematite catalyst for the effective decomposition of HO and bacteria inactivation was designed. The bactericidal effect is the largest at a low initial bacterial count of 2·10 CFU/L, which is typical for natural surface waters. When using a 5 mM HO solution and a residence time of 104 min, the reduction in the number of E.

New insights into the influence of plasmonic and non-plasmonic nanostructures on the photocatalytic activity of titanium dioxide.

The results of this work cover the influence of plasmonic (gold) and non-plasmonic (palladium) nanostructures on the photocatalytic activity and redox properties of titanium dioxide. Materials decorated with gold, palladium and both materials were examined using photoelectrochemical and spectroelectrochemical methods to establish the changes introduced by the modifications and the possibility of the influence of the plasmonic effect from gold on their activity. Additionally, the photocatalytic tests of hydroxyl radical generation and hydrogen evolution were performed to confirm the activity of modified materials in oxidation and reduction reactions.

Enhanced Solar Fuel Production over In O @Co VO Hierarchical Nanofibers with S-Scheme Charge Separation Mechanism.

The conversion of CO into valuable solar fuels via photocatalysis is a promising strategy for addressing energy shortages and environmental crises. Here, novel In O @Co VO hierarchical heterostructures are fabricated by in situ growing Co VO nanorods onto In O nanofibers. First-principle calculations and X-ray photoelectron spectroscopy (XPS) measurements reveal the electron transfer between In O and Co VO driven by the difference in work functions, thus creating an interfacial electric field and bending the bands at the interfaces.

Phototransformations of TiO/AgO composites and their influence on photocatalytic water splitting accompanied by methanol photoreforming.

This work aimed to revise the mechanism of photocatalytic activity of the TiO/AgO system in photocatalytic water splitting accompanied by methanol photoreforming. The transformation of AgO into silver nanoparticles (AgNPs) during photocatalytic water splitting/methanol photoreforming was monitored using XRD, XPS, SEM, UV-vis, and DRS techniques. The impact of AgNPs, grown on TiO, on its optoelectronic properties was analysed through spectroelectrochemical measurements.

Selective and efficient catalytic and photocatalytic oxidation of diphenyl sulphide to sulfoxide and sulfone: the role of hydrogen peroxide and TiO polymorph.

In this paper, we describe the role of anatase and rutile crystal phases on diphenyl sulphide (PhS) catalytic and photocatalytic oxidation. The highly selective and efficient synthesis of diphenyl sulfoxide (PhSO) and diphenyl sulfone (PhSO) at titanium dioxide was demonstrated. PhS oxidation in the presence of hydrogen peroxide at anatase-TiO can take place both as a catalytic and photocatalytic reaction, while at rutile-TiO only photocatalytic oxidation is possible.

Interfacial Charge Transfer Complexes in TiO-Enediol Hybrids Synthesized by Sol-Gel.

Metal oxide-organic hybrid semiconductors exhibit specific properties depending not only on their composition but also on the synthesis procedure, and particularly on the functionalization method, determining the interaction between the two components. Surface adsorption is the most common way to prepare organic-modified metal oxides. Here a simple sol-gel route is described as an alternative, finely controlled strategy to synthesize titanium oxide-based materials containing organic molecules coordinated to the metal.

Near-Infrared-Triggered Nitrogen Fixation over Upconversion Nanoparticles Assembled Carbon Nitride Nanotubes with Nitrogen Vacancies.

Photocatalytic artificial fixation of N to NH occurs over NaYF:Yb,Tm (NYF) upconversion nanoparticles (NPs) decorated carbon nitride nanotubes with nitrogen vacancies (NYF/NV-CNNTs) in water under near-infrared (NIR) light irradiation. NYF NPs with a particle size of ca. 20 nm were uniformly distributed on the surface of NV-CNNTs.

Combined Spectroscopic Methods of Determination of Density of Electronic States: Comparative Analysis of Diffuse Reflectance Spectroelectrochemistry and Reversed Double-Beam Photoacoustic Spectroscopy.

The diffuse reflectance spectroelectrochemistry (SE-DRS) and reversed double-beam photoacoustic spectroscopy (RDB-PAS) provide unique, complementary information on the density of electronic states (DOS) in the vicinity of the conduction band bottom. The measurements are performed under quite different conditions, representing the solid/liquid and solid/gas interfaces in SE-DRS and RDB-PAS, respectively. DOS profiles obtained from both types of measurements can be considered as unique "fingerprints" of the tested materials.

Catalytic and photocatalytic oxidation of diphenyl sulphide to diphenyl sulfoxide over titanium dioxide doped with vanadium, zinc, and tin.

Samples of TiO (P25) doped with zinc, tin, and vanadium, thermally treated at 550 °C for 6 h, were tested as catalysts and photocatalysts for the oxidation of diphenyl sulphide to diphenyl sulfoxide and sulfone, using hydrogen peroxide as an oxidation agent. Thermal treatment of pure TiO and its vanadium-doped forms resulted in a decrease of anatase and an increase of rutile content. The opposite effect was observed for TiO doped with zinc or tin, where thermal treatment resulted in the rutile to anatase phase transition.

Attaching titania clusters of various size to reduced graphene oxide and its impact on the conceivable photocatalytic behavior of the junctions-a DFT/D + U and TD DFTB modeling.

DFT/D  +  U and density functional based tight binding (DFTB) molecular modeling was used to investigate the role of the structural, electronic and optical properties of reduced graphene oxide surface (r-GO), hybridized with hydrated TiO moieties of various size, ranging from small molecular TiO clusters into extended TiO rutile type nanocrystals of ~5 nm diameter. The calculated adhesion energies, varying from  -5.048 eV (r-GO|TiO), -12.

Generation of hydroxyl radicals and singlet oxygen by particulate matter and its inorganic components.

Particulate matter (PM) can strongly affect redox biochemistry and therefore induce the response of the immune system and aggravate the course of autoimmune diseases. Nanoparticles containing transition metal compounds possessing semiconductor properties (TiO, ZnO) may act as photocatalysts and accelerate the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). In this study, the NIST standard reference material, SRM 1648a, has been analyzed in terms of this consideration.

Chemical composition of submicron and fine particulate matter collected in Krakow, Poland. Consequences for the APARIC project.

Submicron particulate matter containing particles with an aerodynamic diameter ≤1 μm (PM1) are not monitored continuously by Environmental Protection Agencies around the World and are seldom studied. Numerous studies have indicated that people exposed to ultrafine (≤100 nm), submicron and fine particulate matter containing particles with an aerodynamic diameter ≤2.5 μm (PM2.

Periopathogens differ in terms of the susceptibility to toluidine blue O-mediated photodynamic inactivation.

Background: The main goal of periodontal therapy is to eliminate the infection spreading in periodontium. Antimicrobial photodynamic therapy may be applied in order to eradicate pathogens remaining in periodontal tissues after conventional mechanical debridement, to improve the treatment results. The aim of this in vitro study was to evaluate the susceptibility of selected key periopathogens to toluidine blue O-mediated photodynamic inactivation and the influence of photosensitizer's concentration and light dose on the effectiveness of this process.

Photosensitization of CuI - the role of visible light induced Cu→ Cu transition in photocatalytic degradation of organic pollutants and inactivation of microorganisms.

Bare and photosensitized copper iodides were tested in photocatalysed degradation of an organic dye (Acid Red 1) and inactivation of fungi (Saccharomyces cerevisiae). CuI, with the band gap energy slightly lower than that of TiO, appeared to be highly efficient in these processes. Sensitization of copper iodide was achieved by surface modification with [Cu(SCN)(phen)].

Structural, Optical, and Magnetic Properties of Zn-Doped CoFeO Nanoparticles.

The effect of Zn-doping in CoFeO nanoparticles (NPs) through chemical co-precipitation route was investigated in term of structural, optical, and magnetic properties. Both XRD and FTIR analyses confirm the formation of cubic spinel phase, where the crystallite size changes with Zn content from 46 to 77 nm. The Scherrer method, Williamson-Hall (W-H) analysis, and size-strain plot method (SSPM) were used to study of crystallite sizes.

Photocatalytic Carbon Dioxide Reduction at p-Type Copper(I) Iodide.

A p-type semiconductor, CuI, has been synthesized, characterized, and tested as a photocatalyst for CO reduction under UV/Vis irradiation in presence of isopropanol as a hole scavenger. Formation of CO, CH , and/or HCOOH was observed. The photocatalytic activity of CuI was attributed to the very low potential of the conduction band edge (i.

Influence of π-Iodide Intermolecular Interactions on Electronic Properties of Tin(IV) Iodide Semiconducting Complexes.

Coordination compounds with a tin center surrounded by both organic and inorganic ligands ([SnI4{(C6H5)3PO}2], [SnI4{(C6H5)2SO}2], and [SnI4(C5H5NO)2]) acting as molecular semiconductors are in the spotlight of this article. This is a new class of hybrid semiconducting materials where optoelectronic properties of inorganic core (SnI4) were tuned by organic ligands. The valence band is located at the inorganic portion of the molecule while the conduction band is made of carbon-based orbitals.

Antimicrobial photodynamic therapy-A discovery originating from the pre-antibiotic era in a novel periodontal therapy.

Antimicrobial photodynamic therapy (aPDT) involves pathogens' destruction caused by means of toxic Reactive Oxygen Species (ROS) that are generated upon the interaction of a photoactivatable substance (photosensitizer), light of the appropriate wavelength and oxygen. Among many clinical applications, it is also used as a supplementary method of treatment of periodontal disease. Many in vitro studies confirmed, that a major periopathogenic bacterium, Porphyromonas gingivalis is susceptible to this method.

Solar energy utilization in the direct photocarboxylation of 2,3-dihydrofuran using CO2.

The conversion of CO2 into high energy products (fuels) and the direct carboxylation of C-H bonds require a high energy input. Energy cannot be derived from fossil carbon, in this case. Solar energy can be used instead, with a low environmental impact and good profit.

An integrated photocatalytic/enzymatic system for the reduction of CO2 to methanol in bioglycerol-water.

A hybrid enzymatic/photocatalytic approach for the conversion of CO2 into methanol is described. For the approach discussed here, the production of one mol of CH3OH from CO2 requires three enzymes and the consumption of three mol of NADH. Regeneration of the cofactor NADH from NAD(+) was achieved by using visible-light-active, heterogeneous, TiO2-based photocatalysts.