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Global environmental, social, and economic challenges call for innovative solutions to food production. Current food production systems require advances beyond traditional paradigms, acknowledging the complexity arising from sustainability and a present lack of awareness about technologies that may help limit, for example, loss of nutrients from soil. Aquaponics, a closed-loop system that combines aquaculture with hydroponics, is a step towards the more efficient management of scarce water, land, and nutrient resources. However, its large-scale use is currently limited by several significant challenges of maintaining desirable water chemistry and pH, managing infections in fish and plants, and increasing productivity efficiently, economically, and sustainably. This paper investigates the opportunities presented by plasma technologies in meeting these challenges, potentially opening new pathways for sustainability in food production.

Photoluminescence of composites containing carbon nanostructures is critical for many modern applications. Of particular significance are metamaterials capable of generating white light photoluminescence within a single structure, as the white luminescence usually needs separate red-green-blue emitters. This work provides an insight into the photoluminescent properties of a promising family of hierarchical metamaterials made of carbon nanocones in a silicon oxide matrix in view of their use as efficient single-layer white light emitters. The composites were prepared using a facile plasma-enhanced technology, followed by a thermal treatment. ATR-FTIR, Raman, SEM, and AFM microscopy and profilometry characterization confirmed the presence of silica and carbon nanocones. The advanced comprehensive photoluminescence studies conducted using solid-state Yb:KGW laser revealed a significant difference in photoluminescent properties for the composites containing sharp nanocones of similar parameters. A comprehensive morphological analysis performed using several analytical techniques including the 2D fast Fourier transform spectra, Hough distributions, spectral density function, and Minkowski functionals revealed the Minkowski boundary functional, ordering, and connectivity to be the most important morphological descriptors for the photoluminescent response. This study suggests that these morphological parameters play a critical role in defining the key properties of advanced metamaterials via the overlap of ψ functions and may therefore be targeted for informed material design and intelligent fabrication.

Graphene-based nanomaterials that combine significant photocatalytic, antioxidant and antibacterial activity are very attractive candidates for biomedical and environmental applications. Conventional chemical synthesis routes may contaminate the resultant materials with toxic molecules, compromising their properties and limiting their use in biomedical applications. Ideally, to avoid any contamination, the nanomaterials should be synthesized from non-toxic precursors and reagents, e.g. foodstuff via a simple technology that does not rely on the use of hazardous chemicals yet produces materials of high quality. Here, we report an environmentally friendly, low cost reduced graphene oxide-silver-silver oxide nanocomposite with strong photocatalytic, antioxidant and antibacterial activity for environmental remediation. The reduced graphene oxide (FRGO) is synthesized from edible sunflower oil via a simple flame synthesis method. Next, silver nanoparticles (Ag/AgO/Ag2O) are produced by phytochemical reduction of AgNO3 using a reducing agent based on flavonoids from Coleus aromaticus (Mexican mint), also used in food industry. Thus-obtained FRGO-Ag/AgO/Ag2O composite is characterized using X-ray diffraction spectroscopy, scanning electron microscopy, fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The degradation of anionic textile dye Methylene blue (MB) is used as a measure of photocatalytic activity of FRGO and FRGO/Ag/AgO/Ag2O, with solution pH, initial dye concentration, and quantity of the catalyst considered as influencing factors. FRGO-Ag/AgO/Ag2O composites show strong antioxidant activity, with improved radical inhibition as well as dye degradation properties when compared to pristine FRGO.

Environmental concerns regarding the use of potentially harmful chemicals and fossil fuels stimulate research efforts on the multifunctional hybrid nanocomposites produced from biowastes via simple environmentally friendly processes. Such nanomaterials could help to combat the escalating environmental issues related to environmental remediation and energy storage, as a step to the renewable energy technology of the future. This work discusses the synthesis of novel nickel-based reduced graphene oxide (rGO) nanostructured composites with superior energy storage and photocatalytic properties. Using a facile hydrothermal method, rGO nanoflakes were synthesized from the negative value coconut coir biowaste and then decorated with functional NiO and NiFe2O4 nanoparticles to produce hierarchical functional nanocomposites. Benefiting from the synergies arising from the concomitant use of NiFe2O4 nanoparticles and rGO nanoflakes, the resultant nanocomposites yielded excellent specific capacitance of 599.9 F/g at current density of 1 Ag-1 and retention rate of 86.5% even after 2000 cycles. Moreover, the composite exhibited excellent efficiency of visible light driven photocatalytic degradation of 96.5%. Thus, our material is essentially multifunctional and importantly, it demonstrates quite pronounced electrochemical and photocatalytic activities when produced in a simple, single technological route. These findings confirm that the developed multifunctional nanostructured composite is a strong candidate material for energy and environmental remediation applications.

Low-dimensional copper oxide nanostructures are very promising building blocks for various functional materials targeting high-demanded applications, including energy harvesting and transformation systems, sensing and catalysis. Featuring a very high surface-to-volume ratio and high chemical reactivity, these materials have attracted wide interest from researchers. Currently, extensive research on the fabrication and applications of copper oxide nanostructures ensures the fast progression of this technology. In this article we briefly outline some of the most recent, mostly within the past two years, innovations in well-established fabrication technologies, including oxygen plasma-based methods, self-assembly and electric-field assisted growth, electrospinning and thermal oxidation approaches. Recent progress in several key types of leading-edge applications of CuO nanostructures, mostly for energy, sensing and catalysis, is also reviewed. Besides, we briefly outline and stress novel insights into the effect of various process parameters on the growth of low-dimensional copper oxide nanostructures, such as the heating rate, oxygen flow, and roughness of the substrates. These insights play a key role in establishing links between the structure, properties and performance of the nanomaterials, as well as finding the cost-and-benefit balance for techniques that are capable of fabricating low-dimensional CuO with the desired properties and facilitating their integration into more intricate material architectures and devices without the loss of original properties and function.

The article proposes an improved methodology for assessing the effectiveness of the material transportation and evacuation subsystem in a separate mechanized brigade, which can be used to assess the effectiveness of the rear power system of a separate mechanized brigade during combat operations. The efficiency of completing tasks related to the transportation and evacuation of material assets is mainly influenced by the degree of staffing of automobile units and the condition of vehicles, which is indicated by the coefficient of technical readiness. Also taken into account is the degree of use of carrying capacity and number of flights of vehicles, physical and geographical conditions of the combat area, season and time of the day. All this can significantly affect the daily mileage of vehicles and the fulfillment of tasks related to the transportation and evacuation of material assets. An improved methodology is provided for assessing the effectiveness of the material supply subsystem in a separate mechanized brigade, which can be used to evaluate the effectiveness of the rear support system of a separate mechanized brigade during combat operations. During the study of the process of rear support of troops, an important theoretical and practical task is to evaluate the effectiveness of the material resources (MR) transportation and evacuation subsystems in a separate mechanized brigade (smbri) during combat operations. Certain approaches to solving this problem have been developed in a number of sources. However, the experience of the Anti-Terrorist operation in the territory of Donetsk and Lugansk regions and other armed conflicts of recent decades indicates the need to improve the methodology for assessing the effectiveness of the subsystem of transporting and evacuation MR, which would take into account changes in the requirements for the subsystem of transporting and evacuation MR to the separate mechanized brigade, and increase the efficiency of the logistics support system as a whole. Keywords: separate mechanized brigade, rear support, system efficiency, material resources transportation and evacuation, vehicles, automobile units, transportation of material resources.

As famed quantum physicist W. Pauli once said, “The surface was invented by the devil”. The nonequilibrium state of particles forming the surface, and the presence of dangling bonds transform the surfaces into a 2D reactor with high physical and chemical reactivity. When two such active surfaces are matched, their interface becomes even more reactive, giving rise to novel properties or enhanced performance. For this reason, much effort is applied to design nanoengineered interfacial systems for applications spanning all facets of human life. This review article discusses recent, mostly within two years, progress in the design of complex, sophisticated carbon-based interfacial material systems for energy and photonics applications, with the aim to emphasize some of the most interesting and important examples of such systems. Differences in the processes that take place on flat and 3D (curved) surfaces are discussed, with the view of guiding the design and construction of complex functional interfaces, focusing on several points that are of particular importance to the ongoing development of advanced interfacial material systems.

Carbon nanomaterials derived from agricultural waste streams present an exciting material platform that hits multiple sustainability targets by reducing waste entering landfill, and enabling clean energy and environmental remediation technologies. In this work, the energy and photocatalytic properties of reduced graphene oxide fabricated from coconut coir using a simple reduction method using ferrocene are substantially improved by introducing metallic oxides flakes. A series of cobalt ferrite rGO/CoFe

Marine biofouling remains one of the key challenges for maritime industries, both for seafaring and stationary structures. Currently used biocide-based approaches suffer from significant drawbacks, coming at a significant cost to the environment into which the biocides are released, whereas novel environmentally friendly approaches are often difficult to translate from lab bench to commercial scale. In this article, current biocide-based strategies and their adverse environmental effects are briefly outlined, showing significant gaps that could be addressed through advanced materials engineering. Current research towards the use of natural antifouling products and strategies based on physio-chemical properties is then reviewed, focusing on the recent progress and promising novel developments in the field of environmentally benign marine antifouling technologies based on advanced nanocomposites, synergistic effects and biomimetic approaches are discussed and their benefits and potential drawbacks are compared to existing techniques.

By carefully balancing synergies and antagonisms that arise from incorporating Cu and Ag within a single ZnO-based catalytic platform, the photocatalytic activity of Ag/ZnO based on three-dimensional modified ceramic structures can be further significantly enhanced. The performance of Ag/ZnO heterostructure (Z0) was significantly improved by only 0.2 mol% Cu incorporation (Z0.2) and the first-order degradation kinetics constants (K) of Z0.2 were 2 and 1.5 times higher than that of Z0 under simulated sunlight and UV light. The synergies between Cu dopants and metallic Ag were mainly the significantly enhanced visible light absorption capacity and the prolonged photo-excited charge lifetime. However, with the excessive introduction of Cu precursors, the surface Cu2+ was found to inhibit the interfacial charge transfer between Ag and ZnO NPs under UV and visible light irradiation, but the transformation from Cu2+ to Cu+ was also presumed to be a driving factor for the improvement of photocatalytic efficiency. These interactions may provide a useful pathway for enhancing photocatalytic efficiency of low-cost ZnO-based catalytic platforms.

Graphene and its derivatives have acquired substantial research attention in recent years because of their wide range of potential applications. Implementing sustainable technologies for fabricating these functional nanomaterials is becoming increasingly apparent, and therefore, a wide spectrum of naturally derived precursors has been identified and reformed through various established techniques for the purpose. Nevertheless, most of these methods could only be considered partially sustainable because of their complexity as well as high energy, time, and resource requirements. Here, we report the fabrication of carbon nano-onion-interspersed vertically oriented multilayer graphene nanosheets through a single-step, environmentally benign radio frequency plasma-enhanced chemical vapor deposition process from a low-cost carbon feedstock, the oil from the peel of Citrus sinensis orange fruits. C. sinensis essential oil is a volatile aroma liquid principally composed of nonsynthetic hydrocarbon limonene. Transmission electron microscopy studies on the structure unveiled the presence of hollow quasi-spherical carbon nano-onion-like structures incorporated within graphene layers. The as-fabricated nano-onion-incorporated graphene films exhibited a highly hydrophobic nature showing a water contact angle of up to 129(0). The surface energies of these films were in the range of 41 to 35 mJ.m(-2). Moreover, a chemiresistive sensor directly fabricated using C. sinensis-derived onion-structured graphene showed a p-type semiconductor nature and a promising response to acetone at room temperature. With its unique morphology, surface properties, and electrical characteristics, this material is expected to be useful for a wide range of applications.

Supercapacitors and other innovative devices for electric energy generation and storage could significantly improve ecological situation in large densely populated cities. However, for this to become reality, supercapacitors should be produced en masse via a clean, green technology from the ecologically friendly material, preferably from abundant, sustainable resources, such as agricultural waste that is a by-product of other technological cycles. Many types of agricultural waste could be considered as an abundant, low-cost carbon source for large-scale fabrication of graphene-type materials. Here, we demonstrate that widely available coconut waste can be efficiently converted into reduced graphene oxide via simple catalytic oxidation using ferrocene as an efficient and low-cost catalyst. The structure and morphology of the as-prepared materials were characterized by XRD, SEM, and TEM techniques. The results confirmed the formation of high-quality reduced graphene oxide. The as-prepared graphene oxide was then analyzed as an electrode material for supercapacitor applications. We have found that the material exhibits high performance as an electric double layer capacitor (EDLC) and demonstrates excellent cyclic stability. Therefore, the reduced graphene oxide prepared via a simple, green process from this type of agricultural waste could be a good candidate of the supercapacitor electrodes.

Tunability and fine control of structure and morphology in the patterns of vertically-oriented graphenes is of high importance for their efficient functionalization and application. In this work, we present an experimental and simulation insight into the formation of graphene structures. Detailed simulations by an ad hoc model based on a large number of interacting elemental processes were implemented to ensure a deeper insight into the processes which cannot be directly measured and assessed in the experiments, such as relative densities of adsorbed species and density of ion current at the nanostructures. The combination of the experimental and simulation approaches provided a new level of understanding of the processes that govern formation of the graphene network morphology. Moreover, the potential of novel analytical techniques such as Hough transformations, fractal dimension distributions and Minkovski connectivity, 2D FFT transforms, Hough transformation spectra and others for analysis of the graphene array morphology was successfully demonstrated. The evolution of surface morphology of graphene derived from cold-pressed Citrus sinensis oil, a by-product of orange juice production by centrifugation, synthesised via a catalyst‒free process, was investigated using experimental analyses, Raman spectroscopy, scanning electron microscopy and X‒ray photoelectron spectroscopy, and numerous advanced analytical techniques such as distributions of fractal dimensions. National Research Foundation (NRF) This work was supported in part by the following funds and organizations: framework of the PEGASUS (Plasma Enabled and Graphene Allowed Synthesis of Unique nano-Structures) project, funded by the European Union’s Horizon research and innovation programme under grant agreement No. 766894; OSTIn-SRP/EDB, National Research Foundation, and AcRF (Rp6/16 Xs) Singapore; I. L. acknowledges support from the School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology. K.B. acknowledges support from the Australian Research Council.

Plasma-assisted supersonic jet deposition (PA-SJD) is a precise technique for the fabrication of thin films with a desired nanostructured morphology. In this work, we used quadrupole mass spectrometry of the neutral species in the jet and the extensive characterization of TiO

The historic launch of the first several hundred out of 12,000 planned Starlink satellites heralds the arrival of the era of ultra-large satellite constellations. If it will bring new opportunities or insurmountable challenges to astronomy will probably depend on whether you are conducting your observations in space or from the surface of the Earth.

Strong demand for affordable clean energy to support applications ranging from conventional energy supply to space propulsion places spotlight on advanced energy generation using photovoltaic and wind power. Yet, the intermittent nature of solar and wind sources drives the search for energy storage solutions that would permit the needed level of resilience and support further growth in the use of renewable sources of power. Hydrogen generation using sunlight is a promising pathway to decouple demand from supply. Herein, we show how exposure to reactive Ar-H2, Ar-H2-N2, and Ar-O2 plasma environments can notably enhance surface properties of photocatalytic TiO2 nanosheets used in advanced energy generation systems. Treatment using Ar-H2 plasmas produced highly hydrogenated, surface-disordered TiO2 nanosheets with oxygen vacancies, whereas exposure to Ar-H2-N2 plasmas resulted in N doping. Surprisingly, Ar-O2 plasma treatment did not change surface properties of TiO2. Optical emission spectroscopy was used to monitor transient species to further understand surface modification in plasma. Direct measurements demonstrated that among thus-produced samples, hydrogenated TiO2 nanosheets exhibit the highest photocatalytic H2-generation activity under visible-light irradiation, which is also greater than the activity of pure, untreated nanosheets. The mechanism of enhancing the visible-light photocatalytic H2-generation activity on hydrogenated TiO2 nanosheets is also proposed. The level of surface disorder and oxygen vacancies plays an important role in enhancing visible-light absorption and reducing the recombination of photogenerated electrons and holes.

A novel approach to significantly enhance and comprehensively assess the level of nanochannel ordering in self-assembled nanoporous membranes is proposed and tested. An advanced technique based on a two-step anodization and two-step chemical treatment was used to prepare the perfect through membranes by opening channels from the bottom via electrochemical enlargement, and chemical removal of a residual metal and barrier alumina layer. The influence of the process parameters on the self-assembled ordering was studied, and various methods of order assessment were proposed and tested, such as distributions of equivalent disc radii, 2D Fourier transformations, autocorrelation, Hough transformations, Minkowski connectivity, and distributions of nanochannel centre positions. We have demonstrated that self-assembled ordering in nanoscaled membranes could be efficiently tuned by the process parameters, and different assessment methods should be used to comprehensively characterize the order of nanochannels in the nanoporous membranes. To demonstrate the potential of this technique, we show simulations of the narrowing of plasmon spectra in these materials. The proposed fabrication and assessment methods could be used to drastically enhance the properties of nanoporous membranes for nanoelectronics, filters, sensors, bio-active devices and other advanced emerging applications. Finally, our approach could be used for enhancing and tailoring other self-assembled systems and devices of considerable complexity.

Oil spills into ocean or coastal waters can result in significant damage to the environment via pollution of aquatic ecosystems. Absorbents based on reduced graphene oxide (rGO) foams have the capacity to remove minor or major oil spills. However, conventional chemical synthesis of rGO often uses petrochemical precursors, potentially harmful chemicals, and requires special processing conditions that are expensive to maintain. In this work, an alternative cost-effective and environmentally friendly approach suitable for large-scale production of high-quality rGO directly from used cooking sunflower oil is discussed. Thus, produced flaky graphene structures are effective in absorbing used commercial sunflower oil and engine oil, via monolayer physisorption in the case of used sunflower and engine oils facilitated by van der Waals forces, π–π stacking and hydrophobic interactions, π-cation (H+) stacking and radical scavenging activities. From adsorption kinetic models, first-order kinetics provides a better fit for used sunflower oil adsorption (R2 = 0.9919) and second-order kinetics provides a better fit for engine oil adsorption (R2 = 0.9823). From intra-particle diffusion model, R2 for USO is 0.9788 and EO is 0.9851, which indicates that both used sunflower and engine oils adsorption processes follow an intra-particle diffusion mechanism. This study confirms that waste-derived rGO could be used for environmental remediation.

Solid iodine transforms directly into gas when heated — a property that has been used to create cheap, compact engines that could make large networks of small satellites commercially viable. Cheap propulsion engine performs well in space.

It is still problematic to define a direct relationship between specific properties of a nanostructured surface (e.g., wettability) and its morphology. Not surprisingly, scientists continue to explore en masse the cut-and-try method. In this work, new insights are presented into the correlation of functional properties of the complex nanocomposites with their morphological characteristics. Using polyethylene-terephthalate (PET) as a model material due to its importance and wide use in experiments, super-hydrophilic nanocomposites amenable to be used in a variety of industrial applications are first developed, by exposing PET samples to oxygen plasma under controlled conditions. The morphology of the surfaces is confirmed using AFM and SEM techniques, and wettability in air and its oleophobic properties in water using contact angle and roll-off measurements. Next, different analytical tools such as Minkowski connectivity (Euler-Poincaré characteristic), Hough distributions and 2D FFT are applied to study ordering, connectivity, and fractal characteristics of the samples. It is concluded that fractal dimension, along with ordering and connectivity, are among the major characteristics of the nanocomposite that determine many important physical and chemical properties of the functional nanomaterials, and the fractal dimension could be a target morphological feature to inform the design of fabrication technology.

Plasma and metamaterials: what new advances in space micro-propulsion systems can they bring when used together? The aim of this concise review article is to attract attention of the space propulsion scientists and engineers, along with experts working in the fields of micro-machines, optics, communication, and other hi-tech devices, to the opportunities that arise from different possible combinations of plasma and metamaterials. Along with plasma-based techniques used for the fabrication of complex metamaterials, we examine two unusual plasma/metamaterial systems, namely when plasma interacts with a metamaterial, and when plasma itself features some properties of a metamaterial. The fundamental physics behind the principal processes that define the behavior of these systems is briefly outlined. Possible applications in space technology, mainly for micro-propulsion systems for Cubesats and small satellites are also sketched.

Graphene and its derivatives have acquired substantial research attention in recent years because of their wide range of potential applications. Implementing sustainable technologies for fabricating these functional nanomaterials is becoming increasingly apparent, and therefore, a wide spectrum of naturally derived precursors has been identified and reformed through various established techniques for the purpose. Nevertheless, most of these methods could only be considered partially sustainable because of their complexity as well as high energy, time, and resource requirements. Here, we report the fabrication of carbon nano-onion-interspersed vertically oriented multilayer graphene nanosheets through a single-step, environmentally benign radio frequency plasma-enhanced chemical vapor deposition process from a low-cost carbon feedstock, the oil from the peel of

Nitrogen-doped graphene-based aerogels with three levels of hierarchically organized pores were prepared via a simple environmentally friendly process, and successfully tested in supercapacitor applications. Mesopores and macropores were formed during the aerogel preparation followed by carbonization and its chemical activation by potassium hydroxide (KOH). These mesopores and macropores consist of amorphous carbon and a 3D graphene framework. Thermal treatment at 700 &deg, C, 800 &deg, C, 900 &deg, C in N2 atmosphere was done to etch out the amorphous carbon and obtain a stable N-doped 3D graphene. Specific capacitance values obtained from the electrochemical measurements are in the range of 232&ndash, 170 F&times, g&minus, 1. The thus fabricated structures showed excellent cyclic stability, suggesting that these materials have potential as electrodes for solid asymmetric supercapacitors.

International audience; There are a number of pressing problems mankind is facing today that could, at least in part, be resolved by space systems. These include capabilities for fast and far-reaching telecommunication, surveying of resources and climate, and sustaining global information networks, to name but a few. Not surprisingly, increasing efforts are now devoted to building a strong near-Earth satellite infrastructure, with plans to extend the sphere of active life to orbital space and, later, to the Moon and Mars if not further. The realization of these aspirations demands novel and more efficient means of propulsion. At present, it is not only the heavy launch systems that are fully reliant on thermodynamic principles for propulsion. Satellites and spacecraft still widely use gas-based thrusters or chemical engines as their primary means of propulsion. Nonetheless, similar to other transportation systems where the use of electrical platforms has expanded rapidly, space propulsion technologies are also experiencing a shift toward electric thrusters that do not feature the many limitations intrinsic to the thermodynamic systems. Most importantly, electric and plasma thrusters have a theoretical capacity to deliver virtually any impulse, the latter being ultimately limited by the speed of light. Rapid progress in the field driven by consolidated efforts from industry and academia has brought all-electric space systems closer to reality, yet there are still obstacles that need addressing before we can take full advantage of this promising family of propulsion technologies. In this paper, we briefly outline the most recent successes in the development of plasma-based space propulsion systems and present our view of future trends, opportunities, and challenges in this rapidly growing field.

Photovoltaics (PV) as a renewable source of energy has received renewed interest in the immediate provision of sustainable energy to meet market demand in recent years. A key challenge in clean energy research is to ensure that the technology not only provides a sustainable energy source during device operation, but is also environmentally sustainable during the manufacturing phase of the device lifecycle. Plasma sources have been conventionally employed in numerous surface nucleation and nanostructure growth processes due to highly controllable process parameters that enable precise control of material properties at the nanoscale. However, these processes usually employ toxic feedstock as a means to obtain favourable PV characteristics, such as nanotexturing. In this work, an inductively coupled plasma (ICP) system in a cascading cluster configuration setup was employed for fabrication of highly efficient nanotextured PV cells. A 2-step process was developed to use a high density N2 discharge for high density plasma immersion ion implantation (HD-PIII) in group V doping of c-Si samples for high quality junction formation. Subsequently, an Ar + H2 discharge was utilized for the simultaneous nanotexturing of the surface as well as passivation of surface defects through intense hydrogenation from the plasma generated radical flux. The resulting black silicon (b-Si) PV cells fabricated through this process typically have ultra-low reflectance of