Editorial

3 pages, 186 KiB

Open AccessEditorial

Special Issue on Advanced Materials and Nanotechnology for Sustainable Energy and Environmental Applications

by Angela Malara and Patrizia Frontera

Appl. Sci. 2022, 12(15), 7440; https://0-doi-org.brum.beds.ac.uk/10.3390/app12157440 - 25 Jul 2022

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Materials play a very important role in the technological development of a society, greatly impacting people’s daily lives [...] Full article

(This article belongs to the Special Issue Advanced Materials and Nanotechnology for Sustainable Energy and Environmental Applications)

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14 pages, 4022 KiB

Open AccessArticle

Light Harvesting in Silicon Nanowires Solar Cells by Using Graphene Layer and Plasmonic Nanoparticles

by Ali Elrashidi

Appl. Sci. 2022, 12(5), 2519; https://0-doi-org.brum.beds.ac.uk/10.3390/app12052519 - 28 Feb 2022

Cited by 11 | Viewed by 1804

Abstract

In this work, a silicon nanowire solar cell for efficient light harvesting in the visible and near-infrared regions is introduced. In this structure, the silicon nanowires (SiNWs) are coated with a graphene layer and plasmonic nanoparticles are distributed on the top surface of [...] Read more.

In this work, a silicon nanowire solar cell for efficient light harvesting in the visible and near-infrared regions is introduced. In this structure, the silicon nanowires (SiNWs) are coated with a graphene layer and plasmonic nanoparticles are distributed on the top surface of the silicon substrate layer. The proposed structure is simulated using the finite difference time domain (FDTD) method to determine the performance of the solar cell by calculating the open-circuit voltage, fill factor, short-circuit current density, and power conversion efficiency. The absorbed light energy is compared for different nanoparticle materials, namely Au, Ag, Al, and Cu, and Au NPs give the best performance. Different values of the radius of the Au NP are simulated, namely 30, 40, 50, and 60 nm, to determine the optimum radius, and the effect of excess carrier concentration on the solar cell performance is also tested. The obtained open-circuit voltage is 0.63 V, fill factor is 0.73, short-circuit current density is 41.7 mA/cm², and power conversion efficiency is 19.0%. The proposed SiNW solar cell improves the overall efficiency by almost 60%. Furthermore, the effects of the NW length and distance between NWs are also studied in this work. Finally, the distribution of the optical power in different layers along the solar cell and for different solar cell structures is also illustrated in this paper. Full article

(This article belongs to the Special Issue Advanced Materials and Nanotechnology for Sustainable Energy and Environmental Applications)

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10 pages, 2509 KiB

Open AccessFeature PaperArticle

Competitive Detection of Volatile Compounds from Food Degradation by a Zinc Oxide Sensor

by Lucio Bonaccorsi, Andrea Donato, Antonio Fotia, Patrizia Frontera and Andrea Gnisci

Appl. Sci. 2022, 12(4), 2261; https://0-doi-org.brum.beds.ac.uk/10.3390/app12042261 - 21 Feb 2022

Cited by 5 | Viewed by 1783

Abstract

During the phenomenon of food degradation, several volatile organic compounds are generally released. In particular, due to lipid oxidation in stored and packed meat, hexanal is formed as a typical decomposition product. Therefore, its detection can provide an important indication of the quality [...] Read more.

During the phenomenon of food degradation, several volatile organic compounds are generally released. In particular, due to lipid oxidation in stored and packed meat, hexanal is formed as a typical decomposition product. Therefore, its detection can provide an important indication of the quality and conservation of meat. Unfortunately, the simultaneous release of other compounds, such as 1-pentanol and 1-octen-3-ol, during the first phase of the degradation process can have an undesirable effect on the detection of hexanal. In this work, a metal oxide (MOX) sensor based on zinc oxide (ZnO) was prepared and tested for possible use in the monitoring of low concentrations of hexanal. The sensor was expected to detect the target volatile with minimum interference from all the others, when released all at the same time. For this purpose, the ZnO sensor was exposed to both pure and different mixtures of vapors of the main competing organic compounds. Comparing the results of the mixtures to the response relating to pure hexanal, it was highlighted that the presence of 1-pentanol and 1-octen-3-ol decreases the response of the sensor to hexanal in terms of the eR/R₀ ratio, especially at low concentrations (5–10 ppm), while at 50 ppm, the sensor response was comparable with the hexanal quantity, proving that its detection was less affected at higher concentrations. Full article

(This article belongs to the Special Issue Advanced Materials and Nanotechnology for Sustainable Energy and Environmental Applications)

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11 pages, 5226 KiB

Open AccessFeature PaperArticle

Thermal Stability of Ionic Liquids: Effect of Metals

by Francesca Nardelli, Emilia Bramanti, Alessandro Lavacchi, Silvia Pizzanelli, Beatrice Campanella, Claudia Forte, Enrico Berretti and Angelo Freni

Appl. Sci. 2022, 12(3), 1652; https://0-doi-org.brum.beds.ac.uk/10.3390/app12031652 - 04 Feb 2022

Cited by 3 | Viewed by 1664

Abstract

We investigated the thermal stability and corrosion effects of a promising ionic liquid (IL) to be employed as an advanced heat transfer fluid in solar thermal energy applications. Degradation tests were performed on IL samples kept in contact with various metals (steel, copper [...] Read more.

We investigated the thermal stability and corrosion effects of a promising ionic liquid (IL) to be employed as an advanced heat transfer fluid in solar thermal energy applications. Degradation tests were performed on IL samples kept in contact with various metals (steel, copper and brass) at 200 °C for different time lengths. Structural characterization of fresh and aged IL samples was carried out by high-resolution magic angle spinning nuclear magnetic resonance and Fourier transform infrared spectroscopic analyses, while headspace gas chromatography–mass spectrometry was employed to evaluate the release of volatile organic compounds. The combination of the above-mentioned techniques effectively allowed the occurrence of degradation processes due to aging to be verified. Full article

(This article belongs to the Special Issue Advanced Materials and Nanotechnology for Sustainable Energy and Environmental Applications)

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14 pages, 3275 KiB

Open AccessFeature PaperArticle

Morphological Observation of LiCl Deliquescence in PDMS-Based Composite Foams

by Emanuela Mastronardo, Elpida Piperopoulos, Davide Palamara, Andrea Frazzica and Luigi Calabrese

Appl. Sci. 2022, 12(3), 1510; https://0-doi-org.brum.beds.ac.uk/10.3390/app12031510 - 30 Jan 2022

Cited by 3 | Viewed by 2450

Abstract

The LiCl-based heat storage system exhibits a high-energy density, making it an attractive and one of the most investigated candidates for low-temperature heat storage applications. Nevertheless, lithium chloride, due to its hygroscopic nature, incurs the phenomenon of deliquescence, which causes some operational challenges, [...] Read more.

The LiCl-based heat storage system exhibits a high-energy density, making it an attractive and one of the most investigated candidates for low-temperature heat storage applications. Nevertheless, lithium chloride, due to its hygroscopic nature, incurs the phenomenon of deliquescence, which causes some operational challenges, such as agglomeration, corrosion, and swelling problems during hydration/dehydration cycles. Here, we propose a composite material based on silicone vapor-permeable foam filled with the salt hydrate, hereafter named LiCl-PDMS, aiming at confining the salt in a matrix to prevent deliquescence-related issues but without inhibiting the vapour flow. In particular, the structural and morphological modification during hydration/dehydration cycles is investigated on the composite foam, which is prepared with a salt content of 40 wt.%. A characterization protocol coupling temperature scanned X-ray diffraction (XRD) and environmental scanning electron microscopy (ESEM) analysis is established. The operando conditions of the dehydration/hydration cycle were reproduced while structural and morphological characterizations were performed, allowing for the evaluation of the interaction between the salt and the water vapor environment in the confined silicon matrix. The material energy density was also measured with a customized coupled thermogravimetric/differential scanning calorimetric analysis (TG/DSC). The results show an effective embedding of the material, which limits the salt solution release when overhydrated. Additionally, the flexibility of the matrix allows for the volume shrinkage/expansion of the salt caused by the cyclic dehydration/hydration reactions without any damages to the foam structure. The LiCl-PDMS foam has an energy density of 1854 kJ/kg or 323 kWh/m³, thus making it a competitive candidate among other LiCl salt hydrate composites. Full article

(This article belongs to the Special Issue Advanced Materials and Nanotechnology for Sustainable Energy and Environmental Applications)

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10 pages, 2303 KiB

Open AccessArticle

Effect of Working Atmospheres on the Detection of Diacetyl by Resistive SnO₂ Sensor

by Andrea Gnisci, Antonio Fotia, Lucio Bonaccorsi and Andrea Donato

Appl. Sci. 2022, 12(1), 367; https://0-doi-org.brum.beds.ac.uk/10.3390/app12010367 - 31 Dec 2021

Cited by 2 | Viewed by 1846

Abstract

Nanostructured metal oxide semiconductors (MOS) are considered proper candidates to develop low cost and real-time resistive sensors able to detect volatile organic compounds (VOCs), e.g., diacetyl. Small quantities of diacetyl are generally produced during the fermentation and storage of many foods and beverages, [...] Read more.

Nanostructured metal oxide semiconductors (MOS) are considered proper candidates to develop low cost and real-time resistive sensors able to detect volatile organic compounds (VOCs), e.g., diacetyl. Small quantities of diacetyl are generally produced during the fermentation and storage of many foods and beverages, conferring a typically butter-like aroma. Since high diacetyl concentrations are undesired, its monitoring is fundamental to identify and characterize the quality of products. In this work, a tin oxide sensor (SnO₂) is used to detect gaseous diacetyl. The effect of different working atmospheres (air, N₂ and CO₂), as well as the contemporary presence of ethanol vapors, used to reproduce the typical alcoholic fermentation environment, are evaluated. SnO₂ sensor is able to detect diacetyl in all the analyzed conditions, even when an anaerobic environment is considered, showing a detection limit lower than 0.01 mg/L and response/recovery times constantly less than 50 s. Full article

(This article belongs to the Special Issue Advanced Materials and Nanotechnology for Sustainable Energy and Environmental Applications)

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16 pages, 3071 KiB

Open AccessFeature PaperArticle

Hydrothermal Carbonization as Sustainable Process for the Complete Upgrading of Orange Peel Waste into Value-Added Chemicals and Bio-Carbon Materials

by Antonella Satira, Emilia Paone, Viviana Bressi, Daniela Iannazzo, Federica Marra, Paolo Salvatore Calabrò, Francesco Mauriello and Claudia Espro

Appl. Sci. 2021, 11(22), 10983; https://0-doi-org.brum.beds.ac.uk/10.3390/app112210983 - 19 Nov 2021

Cited by 20 | Viewed by 2489

Abstract

In this study, a simple and green protocol to obtain hydrochar and high-added value products, mainly 5-hydroxymethylfurfural (5-HMF), furfural (FU), levulinic acid (LA) and alkyl levulinates, by using the hydrothermal carbonization (HTC) of orange peel waste (OPW) is presented. Process variables, such as [...] Read more.

In this study, a simple and green protocol to obtain hydrochar and high-added value products, mainly 5-hydroxymethylfurfural (5-HMF), furfural (FU), levulinic acid (LA) and alkyl levulinates, by using the hydrothermal carbonization (HTC) of orange peel waste (OPW) is presented. Process variables, such as reaction temperature (180–300 °C), reaction time (60–300 min), biomass:water ratio and initial pH were investigated in order to find the optimum conditions that maximize both the yields of solid hydrochar and 5-HMF and levulinates in the bio-oil. Data obtained evidence that the highest yield of hydrochar is obtained at a 210 °C reaction temperature, 180 min residence time, 6/1 w/w orange peel waste to water ratio and a 3.6 initial pH. The bio-products distribution strongly depends on the applied reaction conditions. Overall, 180 °C was found to be the best reaction temperature that maximizes the production of furfural and 5-HMF in the presence of pure water as a reaction medium. Full article

(This article belongs to the Special Issue Advanced Materials and Nanotechnology for Sustainable Energy and Environmental Applications)

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10 pages, 1365 KiB

Open AccessFeature PaperArticle

A New Biorefinery Approach for the Full Valorisation of Anchovy Residues: Use of the Sludge Generated during the Extraction of Fish Oil as a Nitrogen Supplement in Anaerobic Digestion

by Filippo Fazzino, Emilia Paone, Altea Pedullà, Francesco Mauriello and Paolo S. Calabrò

Appl. Sci. 2021, 11(21), 10163; https://0-doi-org.brum.beds.ac.uk/10.3390/app112110163 - 29 Oct 2021

Cited by 2 | Viewed by 1743

Abstract

Several anchovies species are captured all over the world; they are consumed fresh but also preserved by the industry, either by brine-fermentation or canning in oil. The industrial process generates large amounts of residue (about 50% of the original fish biomass) that is [...] Read more.

Several anchovies species are captured all over the world; they are consumed fresh but also preserved by the industry, either by brine-fermentation or canning in oil. The industrial process generates large amounts of residue (about 50% of the original fish biomass) that is generally used to produce fish flour. In this paper, the advancement of a recently proposed process for the full valorisation of anchovies aimed at the extraction of fish oil (to be used as an omega-3 source) and at the production of biomethane through anaerobic digestion is presented. Particularly, in the experiments presented, a co-digestion of anchovy sludge—used as a nitrogen supplement—and market waste (5% and 95% on a Total Solids basis) was performed. Since the proposed extraction process uses, as a green-solvent, d-limonene, the well-known problems of toxicity for the anaerobic biomass must be overcome during the digestion process. As discussed below, the granular activated carbon (GAC) is used to reclaim and improve anaerobic digestion processes in a reactor displaying clear signs of inhibition. In fact, GAC demonstrates multiple benefits for anaerobic digestion, such as adsorption of toxic substances, biomass selection, and triggering of direct interspecies electron transfer (DIET). Full article

(This article belongs to the Special Issue Advanced Materials and Nanotechnology for Sustainable Energy and Environmental Applications)

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