Piotr Zawadzki

This review examines the design, properties, and applications of graphene quantum dots in energy, environmental, and health sectors. We discuss synthesis methodologies, highlighting the transition from zero-bandgap graphene to luminescent quantum-confined structures. The study details the integration of graphene quantum dots in photovoltaic architectures and lithium-ion batteries to improve stability and efficiency. Environmental sensing capabilities for metal ion detection are explored, emphasizing the safety of carbon-based dots over toxic heavy-metal alternatives. Biomedical applications, including bioimaging and photodynamic therapy, are evaluated with a focus on biocompatibility and renal clearance. Finally, challenges in large-scale production and commercialization are addressed.

This study investigates the anti-cut properties of a composite based on basalt fabrics with varied structural characteristics, including weave and thread density, enhanced with reduced graphene oxide (rGO). The primary aim is to evaluate the potential of integrating rGO into a basalt matrix to improve its resistance to cutting and mechanical damage. The results indicate that adding rGO significantly increases the cutting resistance of the composite. Molecular simulations demonstrate that the composite, which combines a cross-linked LG 700 resin, rGO, and basalt, is one of the most thermodynamically stable configurations due to strong electrostatic interactions between its components. These interactions and the formation of physical bonds at the interfaces stiffen the material, while also allowing for a unique crack-toughening effect. This resilience, which enables the reformation of physical interactions after stress, directly contributes to the composite’s enhanced resistance to catastrophic failure and its observed performance in cutting tests. These findings suggest that basalt–resin with rGO composites hold great potential for applications requiring high mechanical strength and durability, such as protective clothing (e.g., gloves) and anti-vandalism materials. The study concludes that the developed composite represents a promising advancement for materials exposed to cutting forces.

Graphene quantum dots (QGDs), as nascent carbon-based materials, demonstrate remarkable promise in many different applications. Thanks to excellent electrical and thermal properties, great biocompatibility, feasibility of surface functionalization and low cytotoxicity, QGDs can be any material and have many applications, from elastic PV panels to drug delivery. This paper concentrates on relating the structure of the QGD (which is the result of the synthesis method used and consequently the variable degree of defect, the possible presence of functional groups especially in the defect region, etc.) to the resulting physicochemical properties. Therefore, the aim of this study is to theoretically relate and determine the effect of defect amount and type on the value of the HOMO–LUMO gap with respect to possible QGD luminescence colors. Finally, it presents a direction in new graphene-based materials synthesis, where every single defect has a huge impact on its properties.

This article explores the problem of energy conversion and the related storage of hydrogen as an alternative energy source. A method of altering traditional pressure vessels using a composite material based on epoxy resin and graphene is proposed. The test plan for verifying its mechanical properties has been defined. A quantum chemical simulation in Scigress software was performed to analyse the electron distribution in the macromolecules of the epoxy resin and flake graphene. Based on the results of the strength analysis, the strength properties of the composite and the physicochemical changes at the epoxy resin-graphene. It has been proven that the epoxy resin LG 700 with 0.25% by weight of reduced graphene oxide is a potential material for the modification of pressure vessels. The reason behind it is the possibility of improving the mechanical properties of the epoxy resin due to the reorganisation of the polymer chains in the graphene flake region. This effect supports the formation of semicrystalline regions, which can enhance mechanical properties.

Spatial graphene is a 3D structure of a 2D material that preserves its main features. Its production can be originated from the water solution of graphene oxide (GO). The main steps of the method include the crosslinking of flakes of graphene via treatment with hydrazine, followed by the reduction of the pillared graphene oxide (pGO) with hydrogen overpressure at 700 °C, and further decoration with catalytic metal (palladium). Experimental research achieved the formation of reduced pillared graphene oxide (r:pGO), a porous material with a surface area equal to 340 m²/g. The transition from pGO to r:pGO was associated with a 10-fold increase in pore volume and the further reduction of remaining oxides after the action of hydrazine. The open porosity of this material seems ideal for potential applications in the energy industry (for hydrogen storage, in batteries, or in electrochemical and catalytic processes). The hydrogen sorption potential of the spatial graphene-based material decorated with 6 wt.% of palladium reached 0.36 wt.%, over 10 times more than that of pure metal. The potential of this material for industrial use requires further refining of the elaborated procedure, especially concerning the parameters of substrate materials.

Doping of graphene and a controlled induction of disturbances in the graphene lattice allows the production of numerous active sites for lithium ions on the surface and edges of graphene nanolayers and improvement of the functionality of the material in lithium-ion batteries (LIBs). This work presents the process of introducing boron and fluorine atoms into the structure of the reduced graphene during hydrothermal reaction with boron fluoride tetrahydrofuran (BF₃·THF). The described process is a simple, one-step synthesis with little to no side products. The synthesized materials showed an irregular, porous structure, with an average pore size of 3.44–3.61 nm (total pore volume (BJH)) and a multi-layer structure and a developed specific surface area at the level of 586–660 m²/g (analysis of specific surface Area (BET)). On the external surfaces, the occurrence of irregular particles with a size of 0.5 to 10 µm was observed, most probably the effect of doping the graphene structure and the formation of sp³ hybridization defects. The obtained materials show the ability to store electric charge due to the development of the specific surface area. Based on cyclic voltammetry, the tested material showed a capacity of 450–550 mAh/g (charged up to 2.5 V).

The effects of the labor market on environmental issues are an actual problem at the global level, and recommendations are required to achieve equilibrium between labor productivity and environmental protection. Considering the ecological limits of work and the necessity of reducing the working time to mitigate GHG (greenhouse gas) emissions, this paper aims to assess the impact of the labor market on GHG emissions in the EU-28 countries. Using panel data models for 2007–2019, a positive effect of working time for employed persons on GHG emissions was detected. Labor productivity has a positive impact on emissions for most of the developed countries in the EU (old member states), while the effect is negative in the case of most of the new member states, which suggests that more efforts should be made by old member states to correlate labor productivity with a sustainable level of GHG emissions. As a novelty for research in the field, we assessed also the effect of targeted labor utilization on GHG emissions in order to describe the context of a sustainable economy that is an objective for each country in the EU. These results suggest that progress in GHG emissions mitigation might be achieved by reducing the working time for employed persons, which will also improve well-being. These recommendations could be useful also for other developed countries outside the EU that encounter the same difficulties.