Search results for " PHOTOCATALYSIS"

Preface to Materials Science in Photocatalysis

2021

Preparation, Characterization and Photocatalytic Activity of TiO2 Impregnated with the Heteropolyacid H3PW12O40: Photo-assisted Degradation of 2-prop…

2009

Abstract Both commercial and home prepared TiO2 samples impregnated with tungstophosphoric acid (H3PW12O40) were prepared and used for the photo-assisted degradation of 2-propanol in gas–solid regime. The characterization results evidenced a good coverage of the polyoxometalate (POM) onto the surface of both types of TiO2 samples along with a marginal effect of the presence of ethanol or HCl during the POM impregnation step on the specific surface area, porosity, morphology, crystallinity and acidity of the samples. Propene was the main intermediate product found in 2-propanol photocatalytic degradation by using the samples containing POM as the photocatalyst, whereas propanone was mainly o…

SrTiO 3 -based perovskites: Preparation, characterization and photocatalytic activity in gas–solid regime under simulated solar irradiation

2015

Strontium titanate-based perovskites have been prepared in the presence of Y and Co with the aim to substitute Sr and Ti, respectively, in the ST crystalline structure. The obtained samples have been characterized by XRD, Raman spectroscopy, FE-SEM, XPS and tested as photocatalysts in two gas-solid regime reactions: (i) 2-propanol complete mineralization and (ii) propene partial oxidation, using a system simulating solar irradiation. All the tested samples resulted active as photocatalysts but with significant differences. The lattice substitution of Sr by Y displays a beneficial effect on the 2-propanol photodegradation. Conversely, the partial presence of cobalt on the ST surface, as Co-o…

Titania–Silica Materials for Enhanced Photocatalysis

2015

Mesoporous titania–organosilica nanoparticles comprised of anatase nanocrystals crosslinked with organosilica moieties have been prepared by direct co-condensation of a titania precursor, tetrabuthylortotitanate (TBOT), with two organosilica precursors, 1,4-bis(triethoxysilyl) benzene (BTEB) and 1,2-bis(triethoxysilyl) ethane (BTEE), in mild conditions and in the absence of surfactant. These hybrid materials show both high surface areas (200–360 m2 g−1) and pore volumes (0.3 cm3 g−1) even after calcination, and excellent photoactivity in the degradation of rhodamine 6G and in the partial oxidation of propene under UV irradiation, especially after the calcination of the samples. During calci…

Visible-light-induced oxidation of trans-ferulic acid by TiO2 photocatalysis

2012

Abstract The oxidation of trans-ferulic acid (C10H10O4) in aqueous TiO2 dispersion occurs via the formation of a charge-transfer complex on the TiO2 surface that is able to absorb visible light (λ ⩾ 400 nm). The main product is CO2, whereas secondary oxidation products are organic species such as vanillin, caffeic acid, homovanillic acid, and vanillylmandelic acid. Oxidation through the formation of a charge-transfer complex occurs only in the presence of specific TiO2 samples. Experiments in the absence of oxygen, in the presence of bromate ions and by using a phosphate-modified TiO2, have been carried out for investigating the reaction mechanism. In order to study the interaction between …

Photocatalytic CO2 Reduction in Gas-Solid Regime in the Presence of Bare, SiO2 Supported or Cu-Loaded TiO2 Samples

2013

Both commercial and home prepared (HP) TiO2 samples have been tested for the photocatalytic reduction of CO2. (HP) TiO2 powders were prepared by using TiCl4 or Ti(OC4H9)4 as the precursors to obtain HP1 and HP2 samples, respectively. Also HP Cu-loaded and SiO2 supported TiO2 powders were prepared. The HP samples were more active than the commercial ones for the photoreduction of CO2 with and without water vapour. HP1 produced mainly formaldehyde, HP2 principally methane. Acetaldehyde was found to be the primary product obtained when HP1 was supported on SiO2. The addition of Cu increased the photocatalytic reactivity either of bulk and SiO2-supported HP1. In particular, 1 wt % of Cu improve…

Preface

2009

This Special Issue of Catalysis Today includes selected papers presented at the 5th European Conference on Solar Chemistry & Photocatalysis: Environmental Applications (SPEA 5). The conference, held from 4th to 8th October 2008, was organized by Leonardo Palmisano and Vincenzo Augugliaro in Palermo (Italy). The 252 delegates (representing 757 authors) who came from many different European and non-European countries delivered four plenary lectures and 49 oral presentations. To emphasise the poster presentation, the 184 posters were briefly introduced by the appropriate Session Chairman before each oral sessions began. Both oral and poster presentations were divided into the following five to…

Selective Oxidation of Alcohols to Aldehydes by TiO2 Photocatalysis

2011

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, …

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.