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The dominance of plastics in the packaging market is due to their low weight and thickness, which save transportation costs. However, their non-biodegradability poses a significant threat to the environment. Paper, on the other hand, is considered as a safer alternative due to its natural composition and biodegradability. The porous structure of paper limits its application in packaging, and its poor water resistance further restricts its use in humid environments. Therefore, lamination is a method useful tool to improve the barrier properties of paper. Additionally, the researchers are focusing on developing biodegradable and water-based coatings with anti-fat properties as a green alternative to plastic packaging. The impact of a new grease-resistant coating composed of starch, gelatin and sodium alginate on the mechanical properties of paper was investigated through tensile, tearing, and bursting strength tests. The results showed significant improvements in the mechanical properties of the coated paper sheets. Furthermore, the biodegradability test indicated that the paper samples coated with the new composition showed a 50% weight loss after one week of incubation in the soil, and after three weeks, they exhibited 100% weight loss, demonstrating their outstanding biodegradability.

This work reports a facile fabrication method to modify exfoliated molybdenum disulfide (e-MoS2) nanosheets with magnetite nanoparticles with various size distribution. The obtained materials have been utilized as nanofillers of polyethylene to enhance its thermal properties and flame retardance. The incorporation of magnetite modified MoS2 nanosheets leads to the reduction of the peak heat release rate. The best thermal conductivity has been noticed for composites with e-MoS2/Fe3O4 with 2 wt. % of nanofillers. The lowest CO emission was observed for the PE/e-MoS2 composite containing also 2 wt. % of Fe3O4. All composites with exfoliated MoS2 exhibited greater thermal properties in respect to the pristine polyethylene.

In this study, the adsorption of Ni2+ and Fe3+ metal ions from aqueous solutions onto graphene oxide (GO) have been explored. The effects of various experimental factors such as pH of the solution, initial metal ion concentration and temperature were evaluated. The kinetic, equilibrium and thermodynamic studies were also investigated. The adsorption rate data were analyzed using the pseudo-first-order kinetic model, the pseudo-second-order kinetic model and the intraparticle diffusion model. Kinetic studies indicate that the adsorption of both ions follows the pseudo-second-order kinetics. The isotherms of adsorption data were analyzed by adsorption isotherm models such as Langmuir and Freundlich. Equilibrium data fitted well with the Langmuir model. The maximum adsorption capacities of Ni2+ and Fe3+ onto GO were 35.6 and 27.3 mg g−1, respectively. In addition, various thermodynamic parameters, such as enthalpy (ΔHO), entropy (ΔSO) and Gibbs free energy (ΔGO), were calculated.

A PANI/NaTaO3 composite was successfully synthesized by an oxidative polymerization of aniline monomer in hydrochloric acid solution containing sodium tantalate. NaTaO3 at a monoclinic structure was produced via hydrothermal method. The photocatalytic activities of the unmodified NaTaO3 and PANI/NaTaO3 were evaluated for hydrogen generation from an aqueous HCOOH solution and under UV light irradiation. The results showed that the evolution rate of H2 increased significantly when NaTaO3 was modified with PANI. The enhancement of the photocatalytic activity of PANI/NaTaO3 composite was ascribed to the effective charge transfer and separation between NaTaO3 and PANI, which reduced their recombination. This indicates that PANI modification of tantalate photocatalysts may open up a new way to prepare highly efficient catalytic materials for H2 generation.

Graphene – novel 2D material, which possesses variety of fascinating properties, can be considered as a convenient support material for the nanoparticles. In this work various methods of synthesis of reduced graphene oxide with metal or metal oxide nanoparticles will be presented. The hydrothermal approach for deposition of platinum, palladium and zirconium dioxide nanoparticles in ethylene glycol/water solution was applied. Here, platinum/reduced graphene oxide (Pt/RGO), palladium/reduced graphene oxide (Pd/RGO) and zirconium dioxide/reduced graphene oxide (ZrO2/RGO) nanocomposites were prepared. Additionally, manganese dioxide/reduced graphene oxide nanocomposite (MnO2/RGO) was synthesized in an oleic-water interface. The obtained nanocomposites were investigated by transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), Raman spectroscopy and thermogravimetric analysis (TGA). The results shows that GO can be successfully used as a template for direct synthesis of metal or metal oxide nanoparticles on its surface with a homogenous distribution.

The removal of Ni2+ from aqueous solution by magnetic multiwalled carbon nanotube nanocomposite (MMWCNTs-C) was investigated. MMWCNTs-C was characterized by X-ray Diffraction method (XRD), High-Resolution Transmission Electron Microscopy (HRTEM), surface area (BET), and Fourier Transform-Infrared Spectroscopy (FTIR). The effects of initial concentration, contact time, solution pH, and temperature on the Ni2+ adsorption onto MMWCNTs-C were studied. The Langmuir and Freundlich isotherm models were applied to fit the adsorption data. The results showed that the adsorption isotherm data were fitted well to the Langmuir isotherm model with the maximum monolayer adsorption capacity of 2.11 mg g–1. The adsorption kinetics was best described by the pseudo-second-order model. The thermodynamic parameters, such as ΔHo, ΔGo and ΔSo, were also determined and evaluated. The adsorption of Ni2+ is generally spontaneous and thermodynamically favorable. The values of ΔHo and ΔGo indicate that the adsorption of Ni2+ onto MMWCNTs-C was a physisorption process.

Calcination and microwave-assisted hydrothermal processing of precipitated zirconium dioxide are compared. Characterization of synthesized products of these two technologies is presented. The infiuence of thermal treatment up to 1200oC on the structural and spectroscopic properties of the so-obtained zirconium dioxide is examined. It was found that initial crystallization of material inhibits the crystal growth up to the 800oC (by means of XRD and TEM techniques), while the material crystallized from amorphous hydroxide precursor at 400oC, exhibits 26 nm sized crystallites already. It was found using the TG technique that the temperature range 100–200oC during the calcination process is equivalent to a microwave hydrothermal process by means of water content. Mass loss is estimated to be about 18%. Based on X-ray investigations it was found that the initial hydroxide precursor is amorphous, however, its luminescence activity suggests the close range ordering in a material.

The results of investigation of the cement composites modified with 5% of silica-magnetite nanostructures of the core-shell type are presented in the paper. The nanoindentation method employing three-sided pyramidal Berkovich indenter was used in the research. The mechanical properties and microstructure of the modified cement composites were evaluated on the basis of the values of hardness and indentation modulus measured inside the cement matrix and in the aggregate-paste interfacial zone. The results were compared with those obtained for the reference composites without nanostructures. The positive influence of the presence of silica-magnetite nanoparticles on the tested properties was found out.

Near-infrared (NIR) emitting phosphors draw much attention because they show great applicability and development prospects in many fields. Herein, a series of inverse spinel-type structured LiGa5O8 phosphors with a high concentration of Cr3+ activators is reported with a dual emission band covering NIR-I and II regions. Except for strong ionic exchange interactions such as Cr3+-Cr3+ and Cr3+ clusters, an intervalence charge transfer (IVCT) process between aggregated Cr ion pairs is proposed as the mechanism for the ~1210 nm NIR-II emission. Comprehensive structural and luminescence characterization points to IVCT between two Cr3+ being induced by structural distortion and further enhanced by irradiation. Construction of the configurational energy level diagram enabled elucidation of this transition within the IVCT process. Therefore, this work provides insight into the emission mechanism within the high Cr3+ concentration system, revealing a new design strategy for NIR-II emitting phosphors to promote its response., (© 2024 Wiley‐VCH GmbH.)

Photocatalytic hydrogen evolution holds great promise for addressing critical energy and environmental challenges, making it an important area in scientific research. One of the most popular photocatalysts is graphitic carbon nitride (gCN), which has emerged as a noteworthy candidate for hydrogen generation through water splitting. However, ongoing research aims to enhance its properties for practical applications. Herein, we introduce a green approach for the fabrication of porous few-layered gCN with surface modifications (such as oxygen doping, carbon deposition, nitrogen defects) with promoted performance in the hydrogen evolution reaction. The fabrication process involves a one-step solvothermal treatment of bulk graphitic carbon nitride (bulk-gCN) in the presence of different sugars (glucose, sucrose, and fructose). Interestingly, the conducted time-dependent process revealed that porous gCN exfoliated in the presence of fructose at 180 °C for 6 h (fructose_6h) exhibits a remarkable 13-fold promotion of photocatalytic hydrogen evolution compared to bulk-gCN. The studied materials were extensively characterized by microscopic and spectroscopic techniques, allowing us to propose a reaction mechanism for hydrogen evolution during water-splitting over fructose_6h. Furthermore, the study highlights the potential of employing a facile and environmentally friendly fructose-assisted solvothermal process to improve the efficiency and stability of catalysts based on graphitic carbon nitride., (© 2024. The Author(s).)

This study presents a new approach towards the production of sol-gel silica-coated Bi 2 O 3 /Gd 2 O 3 cement additives towards the improvement of early mechanical performance and radiation attenuation. Two types of silica coatings, which varied in synthesis method and morphology, were used to coat Bi 2 O 3 /Gd 2 O 3 structures and evaluated as a cement filler in Portland cement pastes. Isothermal calorimetry studies and early strength evaluations confirmed that both proposed coating types can overcome retarded cement hydration process, attributed to Bi 2 O 3 presence, resulting in improved one day compressive strength by 300% and 251% (depending on coating method) when compared to paste containing pristine Bi 2 O 3 and Gd 2 O 3 particles. Moreover, depending on the type of chosen coating type, various rheological performances of cement pastes can be achieved. Thanks to the proposed combination of materials, both gamma-rays and slow neutron attenuation in cement pastes can be simultaneously improved. The introduction of silica coating resulted in an increment of the gamma-ray and neutron shielding thanks to the increased probability of radiation interaction. Along with the positive early age effects of the synthesized structures, the 28 day mechanical performance of cement pastes was not suppressed, and was found to be comparable to that of the control specimen. As an outcome, silica-coated structures can be successfully used in radiation-shielding cement-based composites, e.g. with demanding early age performances.

Nanoparticles (e.g., graphene oxide, graphene oxide-Fe 3 O 4 nanocomposite or hexagonal boron nitride) loaded with anti-cancer drugs and targeted at cancerous cells allowed researchers to determine the most effective in vitro conditions for anticancer treatment. For this reason, the main propose of the present study was to determine the effect of graphene oxide (GO) with iron oxide (Fe 3 O 4 ) nanoparticles (GO-Fe 3 O 4 ) covalently (c-GO-Fe 3 O 4 -HCPT) and non-covalently (nc-GO-Fe 3 O 4 -HCPT) conjugated with hydroxycamptothecin (HCPT) in the presence of a rotating magnetic field (RMF) on relative cell viability using the MCF-7 breast cancer cell line. The obtained GO-Fe 3 O 4 nanocomposites demonstrated the uniform coverage of the graphene flakes with the nanospheres, with the thickness of the flakes estimated as ca. 1.2 nm. The XRD pattern of GO-Fe 3 O 4 indicates that the crystal structure of the magnetite remained stable during the functionalization with HCPT that was confirmed with FTIR spectra. After 24 h, approx. 49% and 34% of the anti-cancer drug was released from nc-GO-Fe 3 O 4 -HCPT and c-GO-Fe 3 O 4 -HCPT, respectively. The stronger bonds in the c-GO-Fe 3 O 4 -HCPT resulted in a slower release of a smaller drug amount from the nanocomposite. The combined impact of the novel nanocomposites and a rotating magnetic field on MCF-7 cells was revealed and the efficiency of this novel approach has been confirmed. However, MCF-7 cells were more significantly affected by nc-GO-Fe 3 O 4 -HCPT. In the present study, it was found that the concentration of nc-GO-Fe 3 O 4 -HCPT and a RMF has the highest statistically significant influence on MCF-7 cell viability. The obtained novel nanocomposites and rotating magnetic field were found to affect the MCF-7 cells in a dose-dependent manner. The presented results may have potential clinical applications, but still, more in-depth analyses need to be performed.

This study delves into the pressing challenges of climate change and the escalating carbon dioxide (CO 2 ) emissions by exploring hydrogen technology as a sustainable alternative. In particular, there is focus on nickel phosphide-based electrocatalysts, known for their promising performance in hydrogen evolution reactions (HERs) and oxygen evolution reactions (OERs). Therefore, here we have designed a facile strategy to deliver highly porous carbon flakes derived from cellulose fibers via carbonization at 850 °C, yielding highly porous structures and outstanding specific surface area (SSAcel_carb_850_act = 3164 m 2 /g) after activation. As-fabricated carbon was utilized as a support for Ni 12 P 5 with an optimized mass ratio. Electrochemical testing revealed that the composite of Ni 12 P 5 and carbon flakes with a ratio of 100:1, respectively, exhibited the most favorable kinetics for the oxygen evolution reaction (OER). Importantly, the durability tests of this sample demonstrated the most stable behavior and lowest potential change under high current density among the studied samples, making it a promising candidate in practical applications. Moreover, the analysis of electrocatalysts after an OER does not show any changes, indicating that the sample does not undergo undesired intermediate reactions and that unwanted products are not released, explaining its stable behavior. This provides a straightforward approach for creating a cellulose-derived composite with enhanced electroactivity and durability.

Achieving the desired properties of paper such as strength, durability, and printability remains challenging. Paper mills employ calcium carbonate (CaCO 3 ) as a filler to boost paper's brightness, opacity, and printability. However, weak interaction between cellulose fibers and CaCO 3 particles creates different issues in the papermaking industry. Therefore, this study explores the influence of various inorganic additives as crosslinkers such as mesoporous SiO 2 nanospheres, TiO 2 nanoparticles, h-BN nanoflakes, and hydroxylated h-BN nanoflakes (h-BN-OH) on inorganic fillers content in the paper. They were introduced to the paper pulp in the form of a polyethylene glycol (PEG) suspension to enable bonding between the inorganic particles and the paper pulp. Our findings have been revealed based on detailed microscopic and structural analyses, e.g., transmission and scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and N 2 adsorption/desorption isotherms. Finally, the inorganic fillers (CaCO 3 and respective inorganic additives) content was evaluated following ISO 1762:2001 guidelines. Conducted evaluations allowed us to identify the most efficient crosslinker (SiO 2 nanoparticles) in terms of inorganic filler retention. Paper sheets modified with SiO 2 enhance the retention of the fillers by ~12.1%. Therefore, we believe these findings offer valuable insights for enhancing the papermaking process toward boosting the quality of the resulting paper.

Disposable aluminum cans and plastic bottles are common wastes found in modern societies. This article shows that they can be upcycled into functional materials, such as metal-organic frameworks and hierarchical porous carbon nanomaterials for high-value applications. Through a solvothermal method, used poly(ethylene terephthalate) bottles and aluminum cans are converted into MIL-53(Al). Subsequently, the as-prepared MIL-53(Al) can be further carbonized into a nitrogen-doped (4.52 at%) hierarchical porous carbon framework. With an optical amount of urea present during the carbonization process, the carbon nanomaterial of a high specific surface area of 1324 m 2  g -1 with well-defined porosity can be achieved. These features allow the nitrogen-doped hierarchical porous carbon to perform impressively as the working electrode of supercapacitors, delivering a high specific capacitance of 355 F g -1 at 0.5 A g -1 in a three-electrode cell and exhibiting a high energy density of 20.1 Wh kg -1 at a power density of 225 W kg -1 , while simultaneously maintaining 88.2% capacitance retention over 10,000 cycles in two-electrode system. This work demonstrates the possibility of upcycling wastes to obtain carbon-based high-performance supercapacitors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Recently, water oxidation or oxygen evolution reaction (OER) in electrocatalysis has attracted huge attention due to its prime role in water splitting, rechargeable metal-air batteries, and fuel cells. Here, we demonstrate a facile and scalable fabrication method of a rod-like structure composed of molybdenum disulfide and carbon (MoS 2 /C) from parent 2D MoS 2 . This novel composite, induced via the chemical vapor deposition (CVD) process, exhibits superior oxygen evolution performance (overpotential = 132 mV at 10 mA cm -2 and Tafel slope = 55.6 mV dec -1 ) in an alkaline medium. Additionally, stability tests of the obtained structures at 10 mA cm -2 during 10 h followed by 20 mA cm -2 during 5 h and 50 mA cm -2 during 2.5 h have been performed and clearly prove that MoS 2 /C can be successfully used as robust noble-metal-free electrocatalysts. The promoted activity of the rods is ascribed to the abundance of active surface (ECSA) of the catalyst induced due to the curvature effect during the reshaping of the composite from 2D precursor (MoS 2 ) in the CVD process. Moreover, the presence of Fe species contributes to the observed excellent OER performance. FeOOH, Fe 2 O 3 , and Fe 3 O 4 are known to possess favorable electrocatalytic properties, including high catalytic activity and stability, which facilitate the electrocatalytic reaction. Additionally, Fe-based species like Fe 7 C 3 and FeMo 2 S 5 offer synergistic effects with MoS 2 , leading to improved catalytic activity and durability due to their unique electronic structure and surface properties. Additionally, turnover frequency (TOF) (58 1/s at the current density of 10 mA cm -2 ), as a direct indicator of intrinsic activity, indicates the efficiency of this catalyst in OER. Based on ex situ analyzes (XPS, XRD, Raman) of the electrocatalyst the possible reaction mechanism is explored and discussed in great detail showing that MoS 2 , carbon, and iron oxide are the main active species of the reaction., (© 2023 IOP Publishing Ltd.)

The family of graphene-based materials welcomed a new member, borophene, in 2014. Research on synthesis routes and experimental study on physicochemical and biological (especially in vivo) properties still is strongly desired in order to evaluate its practical potential as a drug delivery-system. The effect of two-dimensional borophene nanoflakes on cells, systems and the entire animal organism has not been studied so far. Therefore, we investigated in vivo its biocompatibility with hemocytes in the Tenebrio molitor as a model organism. Short-term studies demonstrated that borophene nanoflakes at doses of 0.5, 1 or 2 µg of nanoflakes per insect did not induce hemocytotoxicity. Hemocytes exposed to nanoflakes showed morphology, adhesiveness and ability to form filopodia as in the control hemocytes. A detailed study indicates that borophene nanoflakes do not: (i) generate intracellular reactive oxygen species in hemocytes, (ii) affect the mitochondrial membrane potential and (iii) interfere with phagocytosis. Therefore, this contribution presents new in vivo insights into the group of two-dimensional materials which are one of the most promising materials for biomedical applications owing to their special structure and unique properties. However, long-term studies in insects and other animals are still necessary to confirm that borophene is biocompatible and biologically safe., (© 2023. The Author(s).)