Leonardo Palmisano

• Chemistry
• Professor (Full) at University of Palermo

The reaction of DMPO as the spin trapping agent with nitrate radicals photocatalytically generated results in the formation of DMPOX showing a highly specific EPR spectrum. The method can be used as a semi‐quantitative and convenient way to detect nitrate radicals in non‐aqueous solutions/suspensions, which was never achieved up to now through EPR...

The reaction of DMPO as the spin trapping agent with nitrate radicals photocatalytically generated results in the formation of DMPOX showing a highly specific EPR spectrum. The method can be used as a semi‐quantitative and convenient way to detect nitrate radicals in non‐aqueous solutions/suspensions, which was never achieved up to now through EPR...

Hydrogen has a lot of promise as an alternative to various carbon containing fuels as burning it releases only water which does not contribute to climate change. However, the standard method of producing hydrogen uses methane as the source, releases carbon dioxide and requires high temperatures and pressures meaning it cannot be considered a sustai...

A commercial TiO2 sample, used as received or hydrothermally treated to increase surface hydroxylation, has been functionalized by surface modification with hexadecyltrimethoxysilane. The anchoring of the silane has been characterized by means of FTIR and solid‐state NMR spectroscopies, and the grafting density was determined by thermogravimetric a...

A commercial TiO2 sample, used as received or hydrothermally treated to increase surface hydroxylation, has been functionalized by surface modification with hexadecyltrimethoxysilane. The anchoring of the silane has been characterized by FTIR and solid‐state NMR spectroscopies, and the grafting density was determined by thermogravimetric and N2 phy...

In the present work, nanowire (NW) structured TiO2 nanoparticles were prepared using the hydrothermal method and characterized by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and BET specific surface area techniques. They were obtained in the anatase phase and presented a high surface area (ca. 300 m²/g). A commercial TiO2 (anatase,...

The ternary chalcogenide ZnIn2S4 (ZIS) has been synthesized by a simple hydrothermal method in which the carcinogen thiacetamide, universally used as a precursor, has been, for the first time, replaced successfully with the harmless thiourea. ZIS has been used as photocatalyst for the partial oxidation of different aromatic alcohols to their corres...

Nanotube/nanowire structured TiO2 samples on Ti plates were prepared by anodic oxidation in aqueous, glycerol or ethylene glycol medium under different experimental conditions and characterized by XRD, SEM‐EDX, electrochemical methods (photocurrent profiles and electrochemical impedance spectroscopy). The nanostructured TiO2 was built on relatively...

In this work, MBi2O4‐P25 (M = Cu, Ni, Co, Zn) composites are successfully synthesized by a simple ball milling method by varying some parameters (rotation speed, rotation time, metal/TiO2 ratio) to optimize the preparation conditions. The noble metal‐free TiO2‐based photocatalysts are used to carry out the partial oxidation of glucose and glycerol...

Different TiO2 modified (with Pt, Cu2O, Nb) photocatalysts have been compared for the photo-reforming of glucose and fructose at ambient conditions with the aim of linking the photoactivity to some structural and surface characteristics. A different degree of conversion, distribution of intermediates and H2 production were observed with the various...

Pt-anatase, -rutile and -brookite TiO 2 photocatalysts were used for glycerol photoreforming. Pt-brookite showed the highest surface hydration and the highest H 2 production.

In recent years, due to the high consumption of drugs both for human needs and for their growing use, especially as regards antibiotics, in the diet of livestock, water pollution has reached very high levels and attracted widespread attention. Drugs have a stable chemical structure and are recalcitrant to many treatments, especially biological ones...

Globular NiFe2O4 nanoparticles have been synthesized by a simple sol–gel method. The structural, morphological, and optical properties of the material have been thoroughly characterized by means of X-ray diffraction, scanning electron microscopy, Fourier transformed infrared and diffuse reflectance spectroscopy, specific surface area, and porosity...

The oxidative cleavage of alkenes represents a relevant chemical process with immense potential for the synthesis of partially oxidized compounds. Several methodologies have been proposed for achieving oxidative cleavage of alkenes, aiming to obtain carbonyl products. However, none of these approaches have been successfully scaled up for industrial...

Bare zinc oxide (ZnO) and Ba-doped ZnO (BZO) samples were prepared by using a simple precipitation method. The effects of Barium doping on the structural, morphological, and optoelectronic properties, as well as on the physico-chemical features of the surface were investigated and correlated with the observed photocatalytic activity under natural s...

Photoreforming of biomass represents an attractive and promising approach to produce renewable and sustainable chemicals and fuels [1,2]. In particular, glucose and fructose, which derive from cellulose, can be used to produce high-value compounds and hydrogen in a sustainable mode. In this work we report the preparation of TiO 2 (HP) based photoca...

The selective photocatalytic oxidation of organic substances is today considered one of the green techniques to synthesize important starting materials in different technological applications. This work reports an efficient, simple and cheap strategy for the synthesis of a new photocatalytic CuBi 2 O 4-TiO 2 (CBO/TiO 2) heterosystem at room tempera...

Nanotube-structured TiO2 electrodes on Ti plates were formed in ethylene glycol solution by the anodic oxidation method applied for different times and calcined at 500 °C. Different amounts of WO3 were decorated on the nanotube surfaces electrochemically. The electrodes were characterized, and the effects of the nanotube length on the Ti plate, dec...

A set of four composite materials was prepared, consisting of a nanosponge matrix based on β-cyclodextrin in which carbon nitride was dispersed. The materials were characterized by the presence of diverse cross-linker units joining the cyclodextrin moieties, in order to vary the absorption/release abilities of the matrix. The composites were charac...

Photoreforming (PR) of biomass can be considered a viable technology under mild experimental conditions to produce hydrogen with a high reaction rate using compounds from renewable resources and waste materials. The application of biomass PR gives rise to both hydrogen generation and biomass waste valorization. The process could be scaled up to obt...

Both water photo‐splitting and photoinduced reforming of biomass components and derivatives at ambient conditions may provide a viable technology to produce green hydrogen. The production of H 2 can be achieved at high rates from compounds obtained from renewable resources and waste materials, thus opening a route for their valorization. Ultimately...

Biomass is a green renewable resource easily available and considered a precious alternative to non-renewable sources for the production of valuable chemicals and fuels [1]. Hexoses, such as glucose, or fructose, are among the most abundant monosaccharides present in biomass and their transformation can give rise to a variety of platform chemicals....

We here investigated a solar photothermo-catalytic combined process where the toluene (as volatile organic compound model) was first oxidized to CO2 which was subsequently converted into solar fuels in a second reactor. For this aim two noble-metal free catalytic systems were used, namely MnOx-ZrO2, which gave the best results for the toluene remov...

In this work anaerobic heterogeneous photocatalytic solar/UV light reforming of glycerol in aqueous media was performed with Pt-photodeposition and noble metal free modified TiO2 photocatalysts prepared through ball milling, a very simple and cheap coupled catalyst preparation method. Different amounts of Cu2O or 3% CuO were loaded on TiO2 using ba...

Composites of C3N4/reduced graphene oxide have been used as photocatalysts for triethanolamine photo-reforming with H2 generation in aqueous solution. The rate of H2 production over the Ag loaded best performing photocatalyst reached 525 μmol·h⁻¹·g⁻¹ which increases to ca. 88,000 μmol·h⁻¹·g⁻¹ in the presence also of 1% of Pt. The apparent quantum e...

A set of metals modified TiO 2 photocatalysts were prepared starting from titanium tetraisopropoxyde and different metal precursors to study the influence of the addition of the various foreign agents on the physico-chemical and photocatalytic properties of the catalysts. The powders were characterized by X-ray diffraction, Raman spectroscopy, spec...

The effects of the nature of some carboxylic acids (oxalic, malic, citric, and tartaric acid) and of the annealing temperature in the preparation of the ZnO photocatalyst by a non-hydrolytic sol-gel route (using zinc acetate as the precursor) have been studied for oxidation of 2-propanol in air as probe reaction in a gas-solid regime. The physico-c...

Within the current production systems, the need for low environmental impact processes to produce chemicals, the treatment of aqueous effluents and the production of fuels is becoming an increasingly urgent challenge. In this context, photoelectrocatalysis (PEC), which couples the electrochemical method (EC) with photocatalysis (PC), can be conside...

Nanotube/nanowire-structured TiO2 was formed on the Ti surface by an anodic oxidation method performed at different potential values (50 or 60 V) and for different times (3 or 5 h). The TiO2 photocatalysts were taken in powder form using the ultrasonic treatment from the Ti electrodes, calcined at different temperatures, and characterized by XRD an...

Photocatalytic chemical transformations in the presence of irradiated TiO2 are generally considered in terms of interfacial electron transfer. However, more elusive energy-transfer-driven reactions have been also hypothesized to occur, mainly on the basis of the indirect evidence of detected reaction products whose existence could not be justified...

Photoelectrocatalytic (PEC) oxidation of glycerol to commercially valuable compounds was carried out using nanotube, nanobelt and nanosponge TiO2 on Ti plates prepared by anodic oxidation method. The plates were characterized by XRD, SEM and electrochemical methods (photocurrent profiles and EIS). Glycerol oxidation experiments were carried out und...

This study reports the anaerobic reduction of maleic acid to succinic acid in aqueous dispersion of different TiO2 based photocatalysts. Some home prepared and commercial solids containing different polymorphic phases of TiO2 and loaded with Pt and Ru were compared at different acidic pHs. The aim of the work was to verify the feasibility of the pr...

The photocatalytic oxidation of 5-hydroxymethyl-2-furfural (HMF) under natural solar irradiation was carried out in liquid–solid regime by using a batch reactor. Home prepared meso-tetra aryl substituted porphyrins (Pps) whether metal-free (H2Pp) or containing Cu(II) or Zn(II) complexes (CuPp, ZnPp), opportunely functionalized with lipophilic [(3-n...

The front cover artwork is provided by the authors, University of Palermo (Italy). The image depicts the synergic coupling of the electrocatalytic system (yellow wire) with a photocatalytic one (blue wire), represented by the weaving of the two wires together. The coupled system is used for the photoelectrocatalytic reduction of carbon dioxide to f...

The Front Cover depicts the synergic coupling of an electrocatalytic system (yellow wire) with a photocatalytic method (blue wire), represented by the weaving of the two wires together. The coupled system is used for the photoelectrocatalytic reduction of carbon dioxide. As discussed in the corresponding Review, coupling of the two technologies all...

The photoactive features of the least common polymorph of TiO2, i.e. brookite, were combined with the thermocatalytic redox ones of cerium oxide, focusing on the effects of the addition of small amounts of Co-Cu oxides for the solar CO2 conversion. By considering the characterization data, surface segregation of the hosted metal oxides on the TiO2-...

Heterogeneous photocatalysis permits meeting stricter environmental limits by using green chemistry concepts. Drinking, industrial, and wastewater, which are often polluted by toxic organic species, can be treated by complete degradation of organic pollutants to small and non-noxious species, without using chemicals and avoiding sludge production a...

Partial photocatalytic oxidation of salicyl alcohol (2-hydroxybenzyl alcohol) to salicylaldehyde in water was investigated under environmental friendly conditions in the presence of home-prepared and commercial TiO2 (Merck and Aeroxide P25) samples under UVA irradiation. The photocatalysts were characterized by using BET, XRD, SEM and/or TEM techni...

The present review summarizes some of the main results achieved in electrochemical, photocatalytic, and (photo)‐electrocatalytic systems for the reduction of carbon dioxide. After a preliminary survey of the electrocatalytic and photocatalytic systems in terms of materials used, efficiencies, operating conditions, and product distribution, it is sh...

The most investigated materials used as heterogeneous photocatalysts for the formation of high-value chemicals under mild experimental conditions are presented in this survey. Only papers reporting reactions carried out in harmless solvents like water, the green solvent par excellence, are reported. Metal oxides have been often used, but also carbo...

The influence of pH on the photocatalytic partial oxidation of 4-methoxybenzyl alcohol (MBA) and vanillyl alcohol (VA) to their corresponding aldehydes in aqueous suspension under UVA irradiation was investigated by using poorly crystalline home-prepared and crystalline commercial TiO2 (BDH, Merck and Degussa P25) photocatalysts. The results clearl...

The use of TiO2 as heterogeneous catalyst and/or active support for metals or other oxides is here reported. Many reactions of industrial relevance involve, in fact, titania-based catalysts, among them, NOx abatement, Fischer–Tropsch and water–gas shift, Deacon and Claus processes, hydrodesulfurizations and hydrogenations, selective reductions and...

The photoelectrocatalytic (PEC) oxidation of 3-pyridinemethanol to 3-pyridinemethanal and vitamin B3 was investigated by using Pt, Au and Pd loaded (as single or bimetallic) nanotube structured TiO2 on Ti plate in water under UVA irradiation. Nanotube structured TiO2 on Ti plate samples were prepared as anode by anodic oxidation method in ethylene...

A set of C 3 N 4 samples has been prepared by using melamine, cyanuric acid and barbituric acid as the precursors. The materials were subjected both to physical and chemical characterization and were used as photocatalysts for the selective oxidation of aromatic alcohols in water suspension under UV and visible irradiation. The photoactivity of the...

Dielectric barrier discharge plasma and photocatalysis have been proposed as tools for decontamination of process water, especially in food industry. The present investigation aims to redefine and identify the features of coupling the two technologies in terms of degradation efficiency of a model compound. Results show that, when the process is car...

The aim of the chapter is to describe some different preparation methods and characterization techniques for bare, supported, and coupled TiO2 samples used in different fields. Particular attention has been paid both to the fundamental aspects of the different TiO2 preparation and characterization methods and the practical applications that the res...

TiO2 is an abundant, biocompatible, and inexpensive semiconductor with unique optoelectronic properties and high chemical stability. This chapter summarizes the main features of TiO2 that underlie the applications described in the present book.

Heterogeneous TiO2 photocatalysis is a promising technology based on the capability of the semiconducting material to generate charges upon irradiation of suitable energy. The photogenerated electrons and holes, in turn, induce redox reactions involving species adsorbed on the surface of the photocatalyst, giving rise to chemical transformations. T...

Fluorination of the TiO2 surface has been often reported as a tool to increase the photocatalytic efficiency due to the beneficial effects in terms of production of oxidizing radicals. Moreover, it is shown that the unique amphiphilic properties of the fluorinated TiO2 (TiO2-F) surface allow one to use this material as a stabilizer for the formulat...

The photocatalytic partial oxidation of tyrosol to hydroxytyrosol, the most powerful and expensive natural antioxidant currently known, has been studied in irradiated aqueous suspensions of TiO2 as the photocatalyst. Three TiO2 samples, two commercial (Merck and P25® Evonik) and a home prepared one, have been used bare or surface modified. The infl...

The thermocatalytic, photocatalytic and photothermo-catalytic oxidation of some volatile organic compounds (VOCs), 2-propanol, ethanol and toluene, was investigated over brookite TiO 2-CeO 2 composites. The multi-catalytic approach based on the synergistic effect between solar photocatalysis and thermocatalysis led to the considerable decrease in t...

The influence of bromide ions on systems containing highly reactive radical species is of great interest for environmental remediation, atmospheric chemistry and synthesis of high added value compounds. In this regard, irradiated TiO2 suspensions are simple and suitable systems to highlight some mechanisms of general validity in the above mentioned...

The Keggin heteropolyacid (HPA), H3PW12O40 (PW12) has been supported on commercial boron nitride (BN) and two types of home prepared carbon nitride (C3N4). The supported PW12 was used in the gas-solid (photo)catalytic 2-propanol dehydration reaction to give propene at atmospheric pressure and temperatures in the range 70–120 °C and resulted more ac...

This chapter deals with water treatments by advanced oxidation processes (AOPs) based on chemical and photochemical reactions. The most used processes are described, and for each of them, the main reaction mechanisms, principles, advantages, drawbacks, performances and formation of by-products, coupled with technologies and their applications to wa...

Surface fluorination improves the photocatalytic activity of TiO2 and the influences of various features of fluorinated TiO2 (TiO2-F) have often been discussed in the literature. The present paper addresses the changes induced by surface fluorination on the morphological, structural, surface and electronic features of TiO2. In particular, X-ray dif...

Composites comprised of Ag3PO4 and bare TiO2 (TiO2@Ag3PO4) or silver doped TiO2 (Ag@TiO2–Ag3PO4) have been synthesized by coupling sol–gel and precipitation methods. For the sake of comparison, also the bare components have been similarly prepared. All the samples have been characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectr...

In the present work, dialysis was used to recover vanillin while being produced by partial photocatalytic oxidation of ferulic acid in an aqueous solution at ambient temperature. The relatively high value of the permeate flux through a dense polyether-block amide membrane allowed continuously extracting vanillin from the reacting solution, thus avo...

Objective The necessity to have green and sustainable industrial processes has promoted new technologies for air and water purification together with the research of new energy sources. In this contest, the TiO2-based photocatalysis can be considered a promising route for both environmental applications aIn this work, we have investigated the photo...

The depletion of fossil fuel requires the search for alternative renewable feedstock and environmentally friendly methods for the production of high value-added compounds and fuels. In this context, the efficient use of biomass has emerged as a significant research field as it represents an alternative green and renewable carbon source. Various tec...

Graphitic carbon nitride (g-C3N4) is a metal-free conjugated polymer which has become a new research hotspot in photocatalysis. It can be used for solar energy exploitation like in solar energy organic synthesis, one of the most new and appealing green applications of heterogeneous photocatalysis. This chapter resumes the state-of-the-art and progr...

Aims The aim of this study was to understand if the presence of K in the in C3N4 could increase the oxidative conversion of HMF to high added value species. Background The influence of the potassium metal cation on the graphitic carbon nitride (g-C3N4) photocatalyst has been studied in the partial oxidation of 5-hydroxymethyl-2-furfural (HMF) to 2...

In this paper the first photoelectrocatalytic 3-pyridinemethanol oxidation to 3-pyridinemethanal and vitamin B3 was investigated. For this aim efficient nanotubes structured TiO2 on Ti plate as photoanode were prepared by anodic oxidation method in ethylene glycol and characterized by XRD, SEM, and photocurrent techniques. The effect of nanotube mo...

The outcomes of gathering leading scholars in solar energy, materials science and energy efficiency at the beginning of the world's energy transition to renewable energy at the "SuNEC-Sun New Energy Conference" held in Sicily between 2011 and 2016 suggests two major achievements and has two lessons to teach.

In the present work we scrutinize the effect of substituents in the phenyl ring of the benzyl alcohol on its photo‐oxidation to the corresponding benzaldehyde driven by polymeric carbon nitride photocatalyst in aqueous medium. It has been established that electron donating (ED) substituents in para‐ and ortho‐position with respect to the CH2OH‐grou...

Differently shape-controlled anatase TiO2 materials were tested as photocatalysts under both simulated and natural solar irradiation. Their photocatalytic activity in 2-propanol and propene partial oxidation and in the complete mineralization of acetaldehyde appears to increase with decreasing the shape control of the TiO2 material. This insight se...

Four different C 3 N 4 specimens have been prepared, a bulk one (MCN), a thermally etched (MCN-TE), a solid prepared by hydrothermally treating MCN with H 2 O 2 (MCN-H 2 O 2 ) and a polymeric carbon nitride-hydrogen peroxide adduct (MCN-TE-H 2 O 2 ). The principal aim of this work was to correlate the capability of the prepared material to generate...

We investigated CO2 photocatalytic reduction coupling, for the first time in literature, the assets offered by the continuous operating mode using C3N4-TiO2 photo-catalyst embedded in a dense Nafion matrix. The reactor performance was analyzed under UV–vis light in terms of productivity, selectivity and converted carbon. Reaction pressure was speci...

This paper focused for the first time on the comparison between three different approach to modify the chemico-physical properties of TiO2-based photocatalysts and their effect in the H2 production by photocatalytic water splitting both under UV and solar light irradiation, under the same experimental conditions. The application of pulsed laser irr...

A long-term test at a laboratory scale with a closed system (a coral reef aquarium)has been carried out to study the potentialities of photocatalytic ozonation and photocatalysis for the removal of noxious organic compounds in recirculating systems (aquaria and recirculating aquaculture systems)working with a minimum make up of new water. Attention...

This study investigated the treatment of a shipboard slop containing commercial gasoline in a pilot plant scale consisting of a membrane biological reactor (MBR) and photocatalytic reactor (PCR) acting in series. The MBR contributed for approximately 70% to the overall slop purification. More precisely, the biological process was able to remove app...

Pickering emulsions provide a new way to enhance the efficiency of photocatalytic degradation of water-insoluble pollutants. Indeed, the semiconductor solid particles dually act as photocatalyst and stabilizer of the emulsion droplets whose size dramatically affects the photocatalytic reaction. The present work aims at the validation of this concep...

In the present chapter, the analogies between photocatalytic systems and the systems where the more common thermally activated reactions take place are highlighted. The objective is to propose a unified approach for the analysis and the design, which, however, must take into account how and why photocatalytic reactors differ from reactors with ther...

Soon after the publication of the first pioneering works on heterogeneous photocatalysis, the number of papers on this topic continuously increased. This intriguing field of research is very complex as it endows with an interdisciplinary overview that involves different aspects of chemistry, physics, material and environmental sciences. Even if pho...