Search results for "photocatalysi"

Selective Oxidation of Alcohols to Aldehydes by TiO2 Photocatalysis

2011

Acid-Base Properties and their Influence on the Photoreactivity of Oxides

1988

It is described the existence on the surface of a solid of acidic and basic centres. The correlation with electron donor-acceptor properties is described. The influence of such centres in influencing the reactivity in a photocatalytic process is discussed. The case of ethanoic acid photodecarboxylation over a series of insulator and semiconductor oxides and their mixtures is briefly reported outlining how the acid-base properties affect the photoreactivity.

Self-Cleaning ZnO Nanosheets for Piezoelectric Sensors

2022

The design of wearable sensors coupling versatile analytical detection to self-cleaning is a highly desired combination, tackling the need of smart devices in response to the recent virus pandemics. To this aim, this work shows ZnO nanostructures obtained by a mild wet-chemistry approach onto ITO/PET flexible supports, resulting in wearable piezoelectric sensors exhibiting photocatalytic activity. ITO surfaces are treated with 0.5 mM KMnO4 aqueous solution (20 minutes, 90°C); ZnO growth is subsequently carried out by a previously shown wet-chemistry method [1]. SEM analysis shows the presence of a good surface coverage of ZnO nanosheets (NSs) (about 1.5 NSs/μm2) in the case of treated ITO, …

Influence of the Substituent on Selective Photocatalytic Oxidation of Aromatic Compounds in Aqueous TiO2 Suspensions.

2006

Experimental results are reported showing that the photocatalytic oxidation of aromatic compounds containing an electron-donor group (EDG) gives rise mainly to ortho- and para-monohydroxy derivatives while in the presence of an electron-withdrawing group (EWG) all the monohydroxy derivatives are obtained.

Reuse and recycling in construction: novel photocatalytic nano-mortars from valorised industrial wastes

2021

Production of novel eco-composite nano-mortars for architectural finishing, designed to combat environmental pollution affecting building shells, is reported. Specimens consist of a natural hydraulic lime mortar matrix doped with various kinds of nanophotocatalysts, produced from valorized industrial wastes: TiO2-hexaferrite from Fe3O2, and Ti(SO4)2-hydroxyapatite from Atlantic codfish bones. Samples were characterized and their photocatalytic activity was evaluated. Analysis showed that industrial wastes may be usefully reused to produce a new generation of sustainable, cheap and multifunctional novel building materials.

Sunlight-induced functionalisation reactions of heteroaromatic bases with aldehydes in the presence of TiO2: A hypothesis on the mechanism

2007

In previous studies we reported a new photocatalytic system involving polycrystalline TiO2 for the selective functionalisation of heteroaromatic bases with ethers and amides. In order to extend the applications of this new reaction and to better understand the mechanism involved, we have examined aromatic and aliphatic aldehydes as acyl radical sources for the nucleophilic addition to protonated N-heteroarenes in acetonitrile as the solvent and TiO2/H2O2 as the photocatalytic system. Acyl radicals may undergo decarbonylation to yield the corresponding alkyl radicals. Acyl/alkyl derivative ratios depend on the nature of the aldehydes, and present a different distribution from that obtained i…

Sunlight-induced reactions of some heterocyclic bases with ethers in the presence of TiO2. A green route for the synthesis of heterocyclic aldehydes

2005

Fundamentals of Heterogeneous Photocatalysis and its Application for Environmental and Synthetic Purposes

2010

Keggin and Wells-Dawson supported heteropolyacids as heterogeneous (photo)catalysts for gas-solid 2-propanol dehydration

2016

Catalytic and photocatalytic tests for 2-propanol dehydration to propene were successfully carried out by using binary materials obtained by supporting a Keggin or Wells-Dawson heteropolyacids via impregnation method to commercial SiO2 or TiO2. (Photo)catalytic 2-propanol dehydration was studied in gas-solid regime by using a continuous (photo)reactor working at atmospheric pressure and 80 °C. Propene and diisopropyl ether were the main reaction products. For the continuous photo-assisted runs the reactor was also illuminated with UV light. The heteropolyacid species played a key role both for the catalytic and the photo-assisted catalytic reactions; indicating that the acidity of the clust…

Electron transfer and energy transfer in heterogeneous photocatalysis

2018

Electron transfer and energy transfer in heterogeneous photocatalysis