Which Are the Main Surface Disinfection Approaches at the Time of SARS-CoV-2?

Among many guidelines issued by the World Health Organization to prevent contagion from novel coronavirus (SARS-CoV-2), disinfection of animate and inanimate surfaces has emerged as a key issue. One effective approach to prevent its propagation can be achieved by disinfecting air, skin, or surfaces. A thorough and rational application of an Environmental Protection Agent for disinfection of surfaces, as well as a good personal hygiene, including cleaning hands with appropriate products (e.g., 60–90% alcohol-based product) should minimize transmission of viral respiratory pathogens such as SARS-CoV- 2. Critical issues, associated with the potential health hazard of chemical disinfectants and the ineffective duration of most of the treatments, have fostered the introduction of innovative and alternative disinfection approaches. The present review aims to provide an outline of methods currently used for inanimate surface disinfection with a look to the future and a focus on the development of innovative and effective disinfection approaches (e.g., metal nanoparticles, photocatalysis, self-cleaning, and self-disinfection) with particular focus on SARS-CoV-2. The research reviews are, usually, focused on a specific category of disinfection methods, and therefore they are limited. On the contrary, a panoramic review with a wider focus, as the one here proposed, can be an added value for operators in the sector and generally for the scientific community

Which Are the Main Surface Disinfection Approaches at the Time of SARS-CoV-2?

Among many guidelines issued by the World Health Organization to prevent contagion from novel coronavirus (SARS-CoV-2), disinfection of animate and inanimate surfaces has emerged as a key issue. One effective approach to prevent its propagation can be achieved by disinfecting air, skin, or surfaces. A thorough and rational application of an Environmental Protection Agent for disinfection of surfaces, as well as a good personal hygiene, including cleaning hands with appropriate products (e.g., 60\u201390% alcohol-based product) should minimize transmission of viral respiratory pathogens such as SARS-CoV-2. Critical issues, associated with the potential health hazard of chemical disinfectants and the ineffective duration of most of the treatments, have fostered the introduction of innovative and alternative disinfection approaches. The present review aims to provide an outline of methods currently used for inanimate surface disinfection with a look to the future and a focus on the development of innovative and effective disinfection approaches (e.g., metal nanoparticles, photocatalysis, self-cleaning, and self-disinfection) with particular focus on SARS-CoV-2. The research reviews are, usually, focused on a specific category of disinfection methods, and therefore they are limited. On the contrary, a panoramic review with a wider focus, as the one here proposed, can be an added value for operators in the sector and generally for the scientific community

FOTOCATALIZZATORI FISSATI MEDIANTE LE FINITURE TRADIZIONALI DEL MARMORINO: UNA STRATEGIA ECOLOGICA TRA CHIMICA E RESTAURO PER RENDERE PIÙ PULITE LE NOSTRE CITTA’

Nella tradizione costruttiva veneziana del rivestimento ad intonaco in marmorino è noto che le finiture superficiali erano basate su particolari lavorazioni di pressatura e lamatura e sulla stesura di additivi di protezione organici (sapone, cera, olio di lino) in modo da rendere le superfici molto resistenti alle aggressioni ambientali. Negli interventi di restauro sulle facciate dell’edilizia storica, nei casi in cui si eseguono integrazioni di marmorini esistenti o rifacimenti estesi, è possibile operare con quelle sostanze protettive, in particolare calce e sapone, che riprendono le tecniche del passato e offrono durabilità simili a quelle antiche. Questa possibilità di lavorare con sostanze protettive fissate in superficie ha offerto l’occasione di sperimentare l’aggiunta di prodotti eco-compatibili e incolori che forniscano anche un miglioramento delle condizioni ambientali. Infatti, sono stati eseguiti una serie di campioni utilizzando materiali nanostrutturati multifunzionali che possono degradare i principali inquinanti ambientali organici e inorganici (NOx, VOC) mediante fotocatalisi, oltre a ridurre gli attacchi batterici e conferire proprietà autopulenti. Sfruttando le caratteristiche leganti della calce e del sapone impiegati per rinforzare i marmorini preesistenti, allo stato secco, o i marmorini di nuova esecuzione, con stesure superficiali a fresco, si sono studiati gli effetti di due fotocatalizzatori basati sul biossido di titanio e sull’ossido di zinco, entrambi considerati in una versione commerciale e in una versione sintetizzata in laboratorio. Per simulare il degrado superficiale è stato impiegato il blu di metilene come modello di inquinante organico in modo da valutare le proprietà fotocatalitiche dei materiali mediante analisi colorimetriche; inoltre sono stati caratterizzati i materiali con altre tecniche di laboratorio: diffrazione ai raggi X (XRD), fisisorbimento di azoto, microscopia elettronica a scansione (SEM) accoppiata ad analisi EDX (Energy Dispersive X ray). I migliori risultati sono stati ottenuti con il biossido di titanio commerciale e l’ossido di zinco sintetizzato in laboratorio applicati sfruttando la capacità legante del sapone. I risultati sono soddisfacenti e aprono un settore innovativo nel campo del restauro che trova nella chimica un supporto verso la biocompatibilità dei materiali impiegati anche per ridurre l’inquinamento presente nell’aria, oltre a ridurre gli attacchi batterici e conferire proprietà autopulenti

Photoreforming of Glucose over CuO/TiO2

Hydrogen production has been investigated through the photoreforming of glucose, as model molecule representative for biomass hydrolysis. Different copper-or nickel-loaded titania photocatalysts have been compared. The samples were prepared starting from three titania samples, prepared by precipitation and characterized by pure Anatase with high surface area, or prepared through flame synthesis, i.e., flame pyrolysis and the commercial P25, leading to mixed Rutile and Anatase phases with lower surface area. The metal was added in different loading up to 1 wt % following three procedures that induced different dispersion and reducibility to the catalyst. The highest activity among the bare semiconductors was exhibited by the commercial P25 titania, while the addition of 1 wt % CuO through precipitation with complexes led to the best hydrogen productivity, i.e., 9.7 mol H2/h kgcat. Finally, a basic economic analysis considering only the costs of the catalyst and testing was performed, suggesting CuO promoted samples as promising and almost feasible for this application

Titanium Dioxide-Based Nanocomposites for Enhanced Gas-Phase Photodehydrogenation

Light-driven processes can be regarded as a promising technology for chemical production within the bio-refinery concept, due to the very mild operative conditions and high selectivity of some reactions. In this work, we report copper oxide (CuO)-titanium dioxide (TiO2) nanocomposites to be efficient and selective photocatalysts for ethanol photodehydrogenation under gas phase conditions, affording 12-fold activity improvement compared to bare TiO2. In particular, the insertion method of the CuO co-catalyst in different TiO2 materials and its effects on the photocatalytic activity were studied. The most active CuO co-catalyst was observed to be highly dispersed on titania surface, and highly reducible. Moreover, such high dispersion was observed to passivate some surface sites where ethanol is strongly adsorbed, thus improving the activity. This kind of material can be obtained by the proper selection of loading technique for both co-catalysts, allowing a higher coverage of photocatalyst surface (complex-precipitation in the present work), and the choice of titania material itself. Loading copper on a high surface area titania was observed to afford a limited ethanol conversion, due to its intrinsically higher reactivity affording to a strong interaction with the co-catalyst

Light-driven processes for fuel production and cultural heritage remediation

Sunlight in an appealing energy source exploitable for a sustainable and equal development of human society, being abundant, widespread and cheap, on a scenario of adaptation strategies for facing the climate change happening on Earth surface. Several kind of chemical reactions required to sustain the society, from fuel production to environmental remediation, can be potentially run exploiting the light as energy source. A light-activated catalyst (photocatalyst) is often needed to allow such reactions to occurs, able to both absorb the photons and decrease the kinetic barrier. The aim of this work was to prepare some earth-abundant oxide-based semiconductor (SC) materials and assessed them in some photocatalyzed reactions, using a selected SC for each process. Titanium dioxide (TiO2) was used for H2 production from biomass, zinc oxide (ZnO) and a mixed iron-copper oxide (CuFeO2) in CO2 photoreduction, while a calcium-based plaster (marmorino) modified with TiO2 and ZnO, was used in cultural heritage photoremediation (self-cleaning). Different characterization techniques were exploited to achieve a comprehensive knowledge of structural, morphological, optical and surface properties of the prepared materials. Finally, the physical-chemical properties of these oxides were correlated to the photoactivity, aiming to understand how these features affect, negatively or positively, the performances of a given reaction

Titanium Dioxide-Based Nanocomposites for Enhanced Gas-Phase Photodehydrogenation

Light-driven processes can be regarded as a promising technology for chemical production within the bio-refinery concept, due to the very mild operative conditions and high selectivity of some reactions. In this work, we report copper oxide (CuO)-titanium dioxide (TiO2) nanocomposites to be efficient and selective photocatalysts for ethanol photodehydrogenation under gas phase conditions, affording 12-fold activity improvement compared to bare TiO2. In particular, the insertion method of the CuO co-catalyst in different TiO2 materials and its effects on the photocatalytic activity were studied. The most active CuO co-catalyst was observed to be highly dispersed on titania surface, and highly reducible. Moreover, such high dispersion was observed to passivate some surface sites where ethanol is strongly adsorbed, thus improving the activity. This kind of material can be obtained by the proper selection of loading technique for both co-catalysts, allowing a higher coverage of photocatalyst surface (complex-precipitation in the present work), and the choice of titania material itself. Loading copper on a high surface area titania was observed to afford a limited ethanol conversion, due to its intrinsically higher reactivity affording to a strong interaction with the co-catalyst

Marmorino and photocatalysts: a meeting between tradition and innovation

Nella sperimentazione che si propone sono stati studiati campioni di marmorino tradizionale veneziano accoppiati a materiali nanostrutturati multifunzionali con proprietà fotocatalitiche. Mediante fotocatalisi questi materiali possono degradare i principali inquinanti ambientali organici e inorganici (VOC, NOx), conferire proprietà autopulenti e ridurre gli attacchi batterici. Sfruttando le caratteristiche leganti della calce e del sapone, sostanze protettive fissate in superficie che riprendono le tecniche del passato, si sono studiati gli effetti di due fotocatalizzatori a base di biossido di titanio e di ossido di zinco, entrambi considerati in una versione commerciale e in una versione sintetizzata in laboratorio. Per simulare il degrado superficiale è stato impiegato il blu di metilene come modello di inquinante organico e diverse tipologie di sporco, in modo da valutare le proprietà fotocatalitiche di self-cleaning dei materiali mediante analisi colorimetriche. Sono state verificate anche le proprietà biocide dei materiali. I migliori risultati sono stati ottenuti con i campioni a base di biossido di titanio commerciale e di ossido di zinco sintetizzato in laboratorio applicati sfruttando la capacità legante del sapone. I risultati sono soddisfacenti, sono stati raggiunti grazie alla collaborazione tra università ed impresa ed aprono un settore innovativo nel campo del restauro intrecciato a quello della chimica.In the proposed experimentation, samples of traditional Venetian marmorino coupled with multifunctional nanostructured materials with photocatalytic properties were studied. By means of photocatalysis they can degrade the main organic and inorganic environmental pollutants (VOC, NOx), confer self-cleaning properties, and reduce bacterial attacks. By exploiting the binding characteristics of lime and soap, protective substances fixed to the surface that reflect the techniques of the past, the effects of two photocatalysts based on titanium dioxide and zinc oxide were studied, both considered in a commercial version and in a version synthesized in the laboratory. To simulate the surface degradation, methylene blue as a model of organic pollutant and different types of dirt were used, to evaluate the photocatalytic self-cleaning properties of the materials by means of colorimetric analyses. The biocidal properties of the materials were also verified. The best results were obtained with samples based on commercial titanium dioxide and lab synthesized zinc oxide applied using the soap. The results are satisfactory, they have been achieved thanks to the collaboration between university and Company and open up an innovative sector in the field of restoration intertwined with chemistry