Uroš Cvelbar

• PhD, Professor
• Head of Department at Jožef Stefan Institute

The large-scale microwave plasma synthesis of graphene and nitrogen-doped graphene with tailored structural properties, crucial for their successful usage applications, has been demonstrated. The developed atmospheric pressure plasma method offers several advantages, including the continuous production of high-quality, free-standing graphene withou...

The production, conversion and storage of energy based on electrocatalysis, mainly assisted by oxygen evolution reaction (OER), plays a crucial role in alkaline water electrolyzers (AWEs) and fuel cells. Nevertheless, the insufficient availability of highly efficient catalyst materials at a reasonable cost that overcome the sluggish electrochemical...

Cellulose nanofibrils are one of the keystone materials for sustainable future, yet their poor water repellency hinders their push into industrial applications. Due to complexity and poor economical outcome and/or processing toxicity of the existing hydrophobization methods, nanocellulose loses against its antagonist plastic in medical and food ind...

Increasing demand for miniatured electronic devices with high power efficiencies and energy densities led to the exponential growth of electrochemical capacitors. Currently, the available electrochemical capacitors deliver the highest performance at direct current (DC), mainly in the low-frequency regions (less than 1 Hz) due to their electrode arc...

For the extended ultra-wideband THz band up to 10 THz and beyond, materials with different functional properties are required. In addition, the THz shielding devices require the desired thickness for different shielding effects, which can be tailored by the surface functionalities. Here, a plasma-assisted soft chemistry approach was used to tailor...

Supercapacitors (SCs) are considered one of the front-runner energy storage devices for future electronic and automobile device applications. Even though their high-power densities, fast charge/discharge, and long cycling stabilities make them promising for future applications, their charge-discharge takes place below 1 Hz, a major issue for using...

Phase transformations through ion exchange reactions represent a relatively new strategy, offering a promising route for synthesizing complex and metastable morphologies and phases in nanoscaled solid ionic materials, which are challenging or even impossible to achieve through standard bottom-up approaches. Moreover, they provide a unique opportuni...

The global research interest in two-dimensional (2D) materials and their derivatives has increased significantly, driven by the requirements of application-oriented materials for different sectors, including energy storage. Among the various classes of material groups, 2D layered materials have emerged as a critical research area due to their high...

Low-temperature plasmas are nowadays widely developed and used for synthesis and functionalization of various materials with applications in areas ranging from microelectronics and aeronautical industry to energy conversion and storage. The focus of the research and applications has lately shifted towards carbon and carbon-based materials synthesis...

We analyzed the effect of the calcination atmosphere and visible-light contribution to an accelerated reaction rate and improved H2 selectivity over 2 wt% Ni/CeO2−x nanorod catalysts. Spectroscopic and structural characterization was performed by operando DRIFTS, in situ Raman, UV-vis and XAS techniques, which were complemented by DFT calculations....

The exceptional tailoriability of electrical properties in reduced graphene oxide (rGO) is a pivotal factor in unleashing its advanced gas sensing capabilities. Amidst various chemically/thermally-driven techniques, plasma reduction emerges as the fastest method with the potential for scalable treatment. This paper demonstrates a controlled plasma-...

Materials with tunable negative electromagnetic performance, i.e., where dielectric permittivity becomes negative, have long been pursued in materials research due to their peculiar electromagnetic (EM) characteristics. Here, this promising feature is reported in materials on the case of plasma‐synthesized nitrogen‐doped graphene sheets with tunabl...

Taking advantage of the high-energy-density microwave plasma environment as a unique 3D space for the self-assembly of free-standing nanostructures, a novel multifunctional platform for the continuous production of graphene and derivatives at the gram scale was developed. The platform is supported by a prototype plasma machine capable of performing...

Hydrogen separation using nanostructured membranes has gained research attention because of its potential to produce high‐purity hydrogen by separating gases at the molecular level. Quadrupole mass spectrometry (QMS) is one method to evaluate these membranes' effectiveness in separating hydrogen from gas mixtures. However, quantifying gases in a mi...

This research examines the effects of dielectric material thickness and geometry on the formation of surface dielectric barrier discharge (DBD) in air. To initiate the discharge process, electrodes are connected to a high voltage source, ionizing the surrounding air and forming a thin layer of plasma near the dielectric material. The electrohydrody...

Copper oxide nanowires have gained attention in the scientific community due to their potential in a wide range of applications, including gas sensing, solar cells, energy storage, photocatalysis, and as antibacterial agents. Despite significant research on their thermal growth, the underlying mechanism remains unresolved, and the exact experimenta...

The facilitated electrochemical properties of plasma play a critical role in enhancing the synthesis and design of functional nanomaterials for the development of novel sensors. The targeted challenge is to customize and tailor functionality at multiple scales to improve detection device performance. In the realm of optoelectronics, plasmonic sensi...

Atmospheric mercury, specifically oxidized mercury (Hg II ), is the largest anthropogenic pool of mercury in the atmosphere. This type of mercury can accumulate in the food chain after undergoing methylation and entering ecosystems through wet and dry deposition. It is important to evaluate the level of wet and dry deposition, but measurements of a...

The spontaneous increase for advanced energy materials to meet consumer requirements demands the designing of smart, high-performing materials for fabricating next-generation energy devices. The requirement is not only for smart materials but also for manufacturing alternative devices to the rapidly exhausting lithium-based batteries. Currently, so...

Bisphenols represent one of the most recognised harmful contaminants found in environment as a result of their extensive use for the industrial production of polycarbonate, epoxy resins, and thermal paper. They are known for their ability to act as endocrine disruptors, as well as for their potential to cause genotoxicity and cytotoxicity. ¹ . Alth...

Fourier transform infrared spectroscopy (FTIR) is one of the most widely used vibrational diagnostic techniques to investigate gas-phase reactive oxygen and nitrogen species (RONS). However, the technique carries intrinsic challenges, particularly in relation to interfering peaks in the spectral data. This study explores the interfacial processes t...

Because of the enormous number of potential compositions comparable to the number of stars in the universe, high entropy alloys (HEAs) are a virtually endless source of materials possessing versatile properties. Among them, HEAs are promising substitutes for critical elements such as rare earths or platinum group metals. Random or incremental devel...

Demand for higher power efficiency devices to be used in the various miniatured and portable equipment has increased and led to significant growth in the electrochemical capacitors. Currently, different available electrochemical capacitors mostly deliver the highest performance at low frequencies (less than 1 Hz) due to the microporous electrode st...

Facilitated electrochemical properties of plasma are crucial for improving functional nanomaterials synthesis and design for novel sensor development. Controlled customization and functionality tailoring at multiscale is the targeted challenge for better detection devices performance. In the modern era of optoelectronics, among various probing appr...

In the present study, we report on the temperature limiting conditions for the growth of copper oxide nanowires via thermal oxidation of copper, which have been puzzling scientists for decades and were up until now unknown. We explore the lowest temperature limits for nanowire synthesis and find the lowest nanowire diameter that can be achieved via...

Complex hierarchical metamaterials are currently the focus of many cutting‐edge studies due to their potential to advance such critically important areas of technology as energy storage and transformation, sensing, photovoltaics, nano‐medicine, antibacterial and self‐regenerating materials. However, the deterministic design of novel hierarchical me...

Bisphenols are widely recognised as toxic compounds that potentially threaten the environment and public health. Here we report the use of cold atmospheric pressure plasma (CAP) to remove bisphenol A (BPA) and bisphenol S (BPS) from aqueous systems. Additionally, methanol was added as a radical scavenger to simulate environmental conditions. After...

Textiles are important components for the development of lightweight and flexible displays useful in smart materials. In particular, halochromic textiles are fibrous materials with a color-changing ability triggered by pH variations mainly based on pH-sensitive dye molecules. Recently, a novel class of 2-aminoimidazole azo dyes was developed with d...

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...

Unwelcomed biofilms are problematic in food industries, surgical devices, marine applications, and wastewater treatment plants, essentially everywhere where there is moisture. Very recently, label-free advanced sensors such as localized and extended surface plasmon resonance (SPR) have been explored as tools for monitoring biofilm formation. Howeve...

Portable electronic devices require high-performance miniaturised electronic components, preferably produced at low cost. In most line-powered applications, alternating current line filters are used to filter AC lines to direct current signals, making filtering capacitors a key necessity in modern electronic devices. Currently, aluminium electrolyt...

The optoelectronic properties of transition metal oxide semiconductors depend on their oxygen vacancies, nanostructures and aggregation states. Here, we report the synthesis and photoluminescence (PL) properties of substoichiometric tungsten oxide (WO3-x) aggregates with the nanorods, nanoflakes, submicro-spherical-like, submicro-spherical and micr...

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 reacti...

It is shown that surface-enhanced Raman spectroscopy (SERS) can identify bacteria based on their genomic DNA composition, acting as a "sample-distinguishing marker". Successful spectral differentiation of bacterial species was accomplished with nanogold aggregates synthesized through single-step plasma reduction of the ionic gold-containing vapored...

In this paper, we explore the development of copper oxide layers and their evolution into nanowires on thermally oxidized copper and underlying chemical processes governing the growth of unidirectional, one-dimensional copper oxide (CuO), especially focusing on the role of underlying oxide layers. Extensive experimental data sets of grown nanowires...

Plasma conversion of ethanol into carbon nanostructures is easily achieved by in-liquid plasmas but also possible with atmospheric pressure plasmas, where plasma forms in the gas phase over the liquid’s surface. Two plasma configurations were used – atmospheric pressure plasma jet (APPJ) and dielectric barrier discharge (DBD). These plasmas configu...

Copper oxide nanowires represent a popular topic in recent research due to their potential use in gas sensors, batteries, supercapacitors etc. One of their advantages is facile synthesis, as they can be synthesized merely by heating metallic copper in the air. Moreover, their parameters, such as length and diameter, can be easily tailored by adjust...

A new low temperature plasma based method for the growth of the vertically aligned graphene nanowalls is developed. The method allows growth of the vertically (or horizontally) aligned graphene at the temperatures of the surfaces as low as 450°C. This low surface temperature growth enables growth suitable for the coating of various surfaces that co...

Considering the increasing demand for advanced energy materials for future energy-related applications, designing promising materials at a low cost is critical. Given the importance of structural design and morphological features of the designed material in energy applications, fabricating materials at the nanoscale with controlled morphology and o...

Cold-atmospheric plasma-assisted deposition has emerged as an efficient technique for synthesising gold nanoparticles (AuNPs). Here, a plasma-vapour interaction is used for the simultaneous reduction and deposition of AuNPs from an inorganic precursor (HAuCl4). As surface analyses suggest, plasma input power plays an important role in reduction eff...

Designing advanced energy materials based on carbon nanostructures that could meet consumer requirements with high performance at low cost and not requiring expensive or precious materials is a green step towards new-gen energy systems. Such systems would be lightweight and could replace rapidly exhausting Li-based batteries. Although several carbo...

Considering the increasing demand for advanced energy materials to meet consumer requirements, developing advanced high-performing materials at low cost in a green approach is the future step towards fabricating next-generation energy devices. The demand is not only for designing advanced materials but also for replacing rapidly exhausting lithium-...

Surface engineering of graphene-based materials with nitrogen is a potential technique for tailoring the electrical and electronic features of the nanostructures. Surface engineered graphene can be fabricated by adsorbing foreign molecules into the graphene lattice or substitutional doping. Considering different chemical and physical doping techniq...

Calibration for gaseous oxidized mercury species by nonthermal plasma oxidation of Hg0 to HgII species in the presence of O2/Cl2/Br2 gas.

The functionalization of polyester fabric (PES) with antimicrobial agents presents huge number of potential applications in advanced products. However, the lack of functional groups and the high PES hydrophobicity make the functionalization processes costly, prolonged and requires the use of polluting chemicals compounds. In this work, dielectric b...

Atmospheric mercury measurements carried out in the recent decades have been a subject of bias largely due to insufficient consideration of metrological traceability and associated measurement uncertainty, which are ultimately needed for the demonstration of comparability of the measurement results.This is particularly challenging for gaseous HgII...

Developing novel, fast and efficient ecologically benign processes for removing organic contaminants is important for the continued development of water treatment. For this reason, this study investigates the implementation of Cold Atmospheric pressure Plasma (CAP) generated in ambient air as an efficient tool for the removal of Bisphenol A (BPA) a...

Antimicrobial textiles are helpful tools to fight against multidrug-resistant pathogens and nosocomial infections. The deposition of silver nanoparticles (AgNPs) onto textiles has been studied to achieve antimicrobial properties. Yet, due to health and environmental safety concerns associated with such formulations, processing optimizations have be...

The possible benefits of an atmospheric pressure plasma jet skin treatment have been tested in vivo on mouse skin. Many studies have been conducted in vitro on mouse skin cells, but only a few in vivo where, due to the complexity of the biological system, plasma can cause severe damages. For this reason, we investigated how kHz plasma generated in...

Atmospheric pressure plasmas are becoming relevant in local microbial deactivation and other combined effects of plasmas on living organisms. For this reason, our research was focussed on optimisation of atmospheric pressure plasma jet (APPJ) parameters to complete the deactivation of different bacteria strains in a medium. Different helium APPJ tr...

Manganese-doped ceria nanoparticles were prepared by hydrothermal synthesis and the prepared samples were thermally treated at 500 °C for 2 hours. The samples were investigated using X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), energydispersive X-ray spectroscopy (EDS), N2 adsorption and X-ray photoelectron sp...

The cellulose-based products are gaining increased interest, especially as a top-choice material for replacing plastics in packaging-related fields. Nevertheless, the high inherent wettability often hinders its advancement in becoming an efficient substitute in packaging industry. To bridge this challenge,the fluorocarbon plasma processing was impl...

Different structured WO3-x nanomaterials were synthesized in ethanoic acid using the WCl6 and Ti(OC4H9)4 precursors. Advanced characterizations reveal that the incorporation of TiO2 leads to the granulation and structural conversion of WO3-x due to the reduction of surface tension on the WO3-x nanoparticles (NPs) and the fast nucleation of the WO3-...

The proliferation and transmission of viruses has become a threat to worldwide biosecurity, as exemplified by the current COVID-19 pandemic. Early diagnosis of viral infection and disease control have always been critical. Virus detection can be achieved based on various plasmonic phenomena, including propagating surface plasmon resonance (SPR), lo...

Sub-stoichiometric tungsten oxide (i.e., WO3-x) materials are advanced multipurpose semiconducting materials. However, it is still a challenge to tune their structure and morphology. Here we report the structural and morphological conversion and the photoluminescence (PL) enhancement of the WO3-x materials synthesized in the mixed acetic and oleic...

Epoxy composites filled by multiwalled carbon nanotubes treated by inductively coupled ammonia plasma were prepared to improve composite intrinsic properties. The ammonia plasma treatment generated amine and oxygenated groups on the carbon nanotube surface, which facilitated its interaction with the epoxy ring and restricted the slippage of epoxy f...

Mycotoxins are widespread chemical entities in the agriculture and food industries that can induce cancer growth and immune deficiency, posing a serious health threat for humankind. These hazardous compounds are produced naturally by various molds (fungi) that contaminate different food products and can be detected in cereals, nuts, spices, and oth...

Conversion-reaction induced charge storage mechanisms of transition metal sulphides have received considerable interest in designing high-capacity electrodes for electrochemical energy storage devices. However, their low conductivity and structural degradation during cycling limit their applications as energy storage devices. A combination of diffe...

Atmospheric pressure plasma jets have been shown to impact several cancer cell lines, both in vitro and in vivo. These effects are based on the biochemistry of the reactive oxygen and nitrogen species generated by plasmas in physiological liquids, referred to as plasma-conditioned liquids. Plasma-conditioned media are efficient in the generation of...

Thermally stable carbon nitride nanostructures have potential applications in surface coatings and automotive fields. In this work, hydrogenated nitrogen-rich carbon nitride nanoparticles have been synthesised via low-pressure low-power plasma vapour deposition technique from methane/nitrogen gas mixture in a dry process. Thermal stability of the i...

The 1D metal oxide nanostructures, including nanowires, are researched for at least two decades. However, the theoretical models on their synthesis and growth mechanisms are still controversial, even for the simplest growth method, namely thermal oxidation of a metallic surface. In this paper, the relevance analysis of the growth conditions reporte...

Photonic techniques based on evanescent waves sensing (such as the surface plasmon resonance (SPR) method) using plasmonic and nanostructured metallic/semiconductor materials hold huge potential in biosensing and associated analysis of biomolecular interactions. However, conventional SPR suffers from low penetration depths (<300 nm), limiting the a...

In the late XX and early XXI century, the uncontrollable and irreversible worldwide spread of macro- (>5 mm), micro- (5 µm–5 mm), and nanoplastic (<5 µm) pollutants have represented a growing concern. Recent ‘food for thought’ research provided by Isobe et al . offers a pessimistic forecast, suggesting the amount of non-conservative microplastics w...

The electronic properties of the graphene materials can be tuned by chemical doping either by the adsorption of foreign molecules into the graphene lattice or by substitutional doping. Among the various chemical and physical doping techniques, plasma-assisted surface treatment techniques are considered as a fast approach to fabricate nitrogen-incor...

There are enormous efforts being made to develop alternative energy storage devices and to meet the energy needs beyond consumer electronics and electric vehicles. Considering batteries and supercapacitors as one of the best performing energy storage devices with high specific energy and power density, there are lots of efforts have been applied to...

In this paper, we report the one−step synthesis of the TiO2/WO3-x hybrid nanomaterials in ethanoic acid using the tungsten hexachloride (WCl6) and titanium butoxide precursors. The characterization results indicate that the WO3-x incorporation in TiO2 nanomaterials leads to the morphology conversion of TiO2 nanomaterials from the nanoparticles to t...

Transition-metal sulfides combined with conductive carbon nanostructures are considered promising electrode materials for redox-based supercapacitors due to their high specific capacity. However, the low rate capability of these electrodes, still considered "battery-type" electrodes, presents an obstacle for general use. In this work, we demonstrat...

Impinging gas jets can induce depressions in liquid surfaces, a phenomenon familiar to anyone who has observed the cavity produced by blowing air through a straw directly above a cup of juice. A dimple-like stable cavity on a liquid surface forms owing to the balance of forces among the gas jet impingement, gravity and surface tension1,2. With incr...

Antibacterial coating is an important strategy preventing bacterial colonization and biofilm formation. One-step synthesis of nanocapsule-containing antibacterial coatings with controlled release of Ag⁺ ions was achieved in the current work by aerosol-assisted atmospheric pressure plasma deposition. The experimental parameters of deposition includi...

The substoichiometric tungsten oxide (WO3-x) nanostructures are important for the catalytic, energy and optoelectronic applications, yet it remains challenging to control their morphologies and oxygen vacancies. Here we address the challenge of synthesizing the WO3-x nanoflakes and nanorods in ethanol and ethanoic acid by solvothermal method, where...

Plasma jets are extensively used in biomedical applications, particularly for exploring cell viability behaviour. However, many experimental parameters influence the results, including jet characteristics, secondary liquid chemistry and protocols used, slowing research progress. A specific interest of the presented research was skin cell behaviour...

Properties of substoichiometric tungsten oxide (WO3-x) semiconducting nanomaterials in diverse applications are morphology-dependent. However, it remains challenging to control morphology and structure of WO3-x nanostructures. Here, we report the solvothermal synthesis of WO3-x nanostructures with different morphologies in tungsten hexachloride-eth...

Cover Picture: The study demonstrates complete removal of aflatoxin B1 from the artificially contaminated corn kernels with an indirect cold atmospheric pressure plasma treatment generated with a surface barrier discharge system working in the ambient air. Furthermore, it presents the first step towards acceptance of plasma technology as a safe foo...

Mycotoxins, the toxic secondary metabolites produced by filamentous fungi, are found in up to 80% of global food and feed crops. Here, we report on the complete removal of aflatoxin B 1 (AFB 1) from the artificially contaminated corn kernels with an indirect cold atmospheric pressure plasma (CAP) treatment generated with a surface barrier discharge...

Hybrid graphene-based nanostructures are considered promising materials for energy storage applications. However, the synthesis of high-quality hybrid graphene nanostructures at high yields is challenging. In the present work we propose a novel, single-step microwave plasma-enabled approach to synthetize customizable hybrid graphene-based nanostruc...