Effect of Metal Cocatalysts and Operating Conditions on the Product Distribution and the Productivity of the CO Photoreduction.

The CO photoreduction is a promising way to convert one of the most abundant greenhouse gases to valuable chemicals. The photoreduction in the liquid phase is limited by the low solubility of CO in water, but this point is overcome here by using an innovative photoreactor, which allows one to work up to pressures of 20 bar, improving the overall productivity. The photoreduction was performed in the presence of NaSO and using in primis commercial titanium dioxide (P25) and a set of titania catalysts functionalized by surface deposition of either monometallic or bimetallic cocatalysts.

Sonophotocatalytic degradation of sodium diclofenac using low power ultrasound and micro sized TiO.

The nonsteroidal anti-inflammatory drug sodium diclofenac (DC) is an emerging water pollutant which resists conventional wastewater treatments. Here the sonophotocatalytic degradation of DC was carried out using micrometric TiO (both pristine and Ag-decorated), UV-A irradiation and 20 kHz pulsed ultrasound. Sonophotocatalytic tests were compared with photolysis, sonolysis, sonophotolysis, sonocatalysis and photocatalysis data performed in the same conditions.

Effect of Carbon Support, Capping Agent Amount, and Pd NPs Size for Bio-Adipic Acid Production from Muconic Acid and Sodium Muconate.

The effect of support, stabilizing agent, and Pd nanoparticles (NPs) size was studied for sodium muconate and t,t-muconic acid hydrogenation to bio-adipic acid. Three different activated carbons (AC) were used (Norit, KB, and G60) and carbon morphology did not affect the substrate conversion, but it greatly influenced the adipic acid yield. 1% Pd/KB Darco catalyst, which has the highest surface area and Pd surface exposure, and the smallest NPs size displayed the highest activity.

Experimental Characterization of Polymer Surfaces Subject to Corona Discharges in Controlled Atmospheres.

Polymeric dielectrics are employed extensively in the power transmission industry, thanks to their excellent properties; however, under normal operating conditions these materials tend to degrade and fail. In this study, samples of low-density polyethylene, polypropylene, polymethyl methacrylate, and polytetrafluorethylene were subjected to corona discharges under nitrogen and air atmospheres. The discharges introduced structural modifications over the polymer surface.

Photocatalytic porcelain grés large slabs digitally coated with AgNPs-TiO.

TiO is employed as both photocatalytic and structural materials, leading to its applications in external coatings or in interior furnishing devices, including cement mortar, tiles, floorings, and glass supports. The authors have already demonstrated the efficiency of photoactive micro-sized TiO and here its industrial use is reported using the digital printing to coat porcelain grés slabs. Many advantages are immediately evident, namely rapid and precise deposition, no waste of raw materials, thus positively affecting the economy of the process.

Ultrasound-assisted impregnation for high temperature Fischer-Tropsch catalysts.

A fraction of the petroleum extracted from oil reservoirs contains associated natural gas. Rather than building infrastructure to recover low volumes of this natural gas, the industry flares or vents it to the atmosphere, which contributes to atmospheric greenhouse gas emissions but also reduces the air quality locally because it contains gaseous sulphur and nitrogen compounds. Converting the natural gas (NG) to hydrocarbons with a small-scale two-step gas-to-liquids process, is an alternative to flaring and venting.

Comparison of Branched and Linear Perfluoropolyether Chains Functionalization on Hydrophobic, Morphological and Conductive Properties of Multi-Walled Carbon Nanotubes.

The functionalization of multi-walled carbon nanotubes (MW-CNTs) was obtained by generating reactive perfluoropolyether (PFPE) radicals that can covalently bond to MW-CNTs' surface. Branched and linear PFPE peroxides with equivalent molecular weights of 1275 and 1200 amu, respectively, have been thermally decomposed for the production of PFPE radicals. The functionalization with PFPE chains has changed the wettability of MW-CNTs, which switched their behavior from hydrophilic to super-hydrophobic.

Simultaneous photodegradation of VOC mixture by TiO powders.

Volatile and semi volatile organic compounds' concentration have dramatically increased in indoor environments in recent years. UV light promotes titanium dioxide, which oxidises various molecules; however, most of the studies report the degradation of a single VOC. Here, we investigate the photo-oxidation of 17 molecules in mixture to have a realistic test of TiO efficacy.

Micro-sized TiO as photoactive catalyst coated on industrial porcelain grès tiles to photodegrade drugs in water.

Pharmaceutical compounds and their metabolites raise worrying questions because of their continuous release and lack of efficient removal by conventional wastewater treatments; therefore, they are being detected in groundwater, surface water and drinking water in increasing concentrations. Paracetamol and aspirin are two of the most commonly used drugs employed as fever reducer, analgesic and anti-inflammatory. They and their metabolites are very often found in river water, so their degradation is necessary in order to render water suitable for human consumption.

Fe-based heterogeneous catalysts for the Fischer-Tropsch reaction: Sonochemical synthesis and bench-scale experimental tests.

The sonochemical synthesis of nanostructured materials owes its origins to the extreme conditions created during acoustic cavitation, i.e., the formation of localized hot spots in the core of collapsing bubbles in a liquid irradiated with high intensity ultrasound (US).

Copper NPs decorated titania: A novel synthesis by high energy US with a study of the photocatalytic activity under visible light.

The most important drawback of the use of TiO2 as photocatalyst is its lack of activity under visible light. To overcome this problem, the surface modification of commercial micro-sized TiO2 by means of high-energy ultrasound (US), employing CuCl2 as precursor molecule to obtain both metallic copper as well as copper oxides species at the TiO2 surface, is here. We have prepared samples with different copper content, in order to evaluate its impact on the photocatalytic performances of the semiconductor, and studied in particular the photodegradation in the gas phase of some volatile organic molecules (VOCs), namely acetone and acetaldehyde.

Porous TiO2 microspheres with tunable properties for photocatalytic air purification.

The synthesis of highly-crystalline porous TiO(2) microspheres is reported using ultrasonic spray pyrolysis (USP) in the presence of colloidal silica as a template. We have exploited the interactions between hot SiO(2) template particles surface and TiO(2) precursor that occur during reaction inside the droplets, to control the physical and chemical properties of the resulting particles. Varying the SiO(2) to titanium precursor molar ratio and the colloidal silica dimension, we obtained porous titania microspheres with tunable morphology, porosity, BET surface area, crystallite size, band-gap, and phase composition.

Photocatalytic NOx abatement: the role of the material supporting the TiO2 active layer.

The importance of the choice of a suitable substrate as supporting material for photoactive TiO(2), either in the form of powders or thin films or in photoactive paints, is frequently disregarded. In this paper four different supports (stainless steel, sand-blasted stainless steel, Teflon and glass) are object of investigation. The final aim is to verify the presence of interactions between the photocatalyst (AEROXIDE(®) TiO(2) P25 by Evonik Degussa Corporation) and the support, directly involved in the photocatalytic activity in the NO(x) abatement.

Photodegradation of Pollutants in Air: Enhanced Properties of Nano-TiO(2) Prepared by Ultrasound.

Nanocrystalline TiO(2) samples were prepared by promoting the growth of a sol-gel precursor, in the presence of water, under continuous (CW), or pulsed (PW) ultrasound. All the samples turned out to be made of both anatase and brookite polymorphs. Pulsed US treatments determine an increase in the sample surface area and a decrease of the crystallite size, that is also accompanied by a more ordered crystalline structure and the samples appear to be more regular and can be considered to contain a relatively low concentration of lattice defects.

Efficiency of 1,4-dichlorobenzene degradation in water under photolysis, photocatalysis on TiO2 and sonolysis.

The rate of 1,4-dichlorobenzene (1,4-DCB) degradation and mineralization in the aqueous phase was investigated either under direct photolysis or photocatalysis in the presence of commercial or sol-gel synthesized TiO2, or under sonolysis at 20 kHz with different power inputs. Two lamps, both emitting in the 340-400 nm wavelength range with different energy, were employed as irradiation sources. Photocatalysis ensured faster removal of 1,4-DCB with respect to sonolysis and direct photolysis.

The beneficial influence of ultrasound in the polymerization of epsilon-caprolactam to polyamide-6 (Nylon 6). Part I: primary experimental results.

Epsilon-caprolactam (CL) polymerization to polyamide-6 (Nylon 6) was studied at different contents of water in CL (0.01-2 wt%), with or without epsilon-amino-caproic acid (ACA) as an activator, applying to the mixture an initial treatment of Ultrasound (US) (17.5-20 kHz) at low temperatures (70-110 degrees C) and for short times (max 10 min).

The beneficial influence of ultrasound in the polymerization of epsilon-caprolactam to polyamide-6 (Nylon 6). Part II: additional experiment to understand the "pre-sonication effect".

Ultrasound (US) "pre-sonication effect" is the beneficial effect of US in the hydrolytic polymerization of epsilon-caprolactam (CL) mixtures with very low water concentrations (about 0.1-1 wt%). It appears after a mild initial treatment of the mixtures with US [17.

Degradation of methyl tert-butyl ether in water: effects of the combined use of sonolysis and photocatalysis.

The degradation of methyl tert-butyl ether (MTBE) in water was kinetically investigated in a O(2)/Ar 80:20 atmosphere employing either sonolysis at 20 kHz, or photocatalysis on TiO(2) (with 315 nm< lambda(irr) <400 nm), or simultaneous sonolysis and photocatalysis (i.e. sonophotocatalysis), as degradation techniques.

Degradation of organic water pollutants through sonophotocatalysis in the presence of TiO(2).

The degradation of 2-chlorophenol and of the two azo dyes acid orange 8 and acid red 1 in aqueous solution was investigated kinetically under sonolysis at 20 kHz and under photocatalysis in the presence of titanium dioxide particles, as well as under simultaneous sonolysis and photocatalysis, i.e. sonophotocatalysis.