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To fill the knowledge gap for borophene, as the youngest member of the two-dimensional (2D) nanomaterials family, a facile, cost effective, scalable and reproducible fabrication route is still strongly required. Among so far studied techniques the potential of pure mechanical processes such as ball milling is not explored yet. Therefore, in this contribution, we explore the efficiency to exfoliate bulk boron into a few-layered borophene induced by mechanical energy in the planetary ball mill. It was revealed that the resulting flakes thickness and distribution can be controlled by (i) rotation speed (250-650 rpm), (ii) time of ball-milling (1-12 hours), and mass loading of bulk boron (1-3 g). Furthermore, the optimal conditions for the ball-milling process to induce efficient mechanical exfoliation of boron were determined to be 450 rpm, 6 hours, and 1 g (450 rpm_6 h_1 g), which resulted in the fabrication of regular and thin few-layered borophene flakes (∼5.5 nm). What is more, the mechanical energy induced during ball-milling, and the heat generated inside, affected the structure of borophene resulting in different crystalline phases. Besides being an additional and interesting discovery, it will also open up opportunities to investigate the relevance between the properties and the emerging phase. Structures labeled as β-rhombohedral, γ-orthorhombic, τ-B and the conditions under which they appear, have been described. Therefore, in our study, we open a new door to obtain a bulk quantity of few-layered borophene for further fundamental studies and practical potential assessment., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Since its discovery, graphene has been widely considered a great material that has advanced the Li-ion battery field and allowed development in its performance. However, most current graphene-related research is focused on graphene-based composites as electrode materials, highlighting the role of graphene in composite materials. Herein, we focused on a three-dimensional composite film with unique sandwich-type architecture based on ultrafast self-expanded and reduced graphene oxide (userGO) and exfoliated WS 2 . This strategy allows non-active agents [e.g., carbon black and poly (vinylidene fluoride)] free electrodes in LIBs in the form of a film. The ultra-quick exothermal nature of the USER reaction allows the rapid release of internally generated gases to create highly porous channels inside the film. Hence, the improved Li-ion transport in the LIBs boosted the electrochemical performance of both film components (ex-WS 2 and reduced graphene), resulting in a high specific capacity of 762 mAh/g at .05 A/g and high Coulombic efficiency (101%) after 1,000 cycles. Overall, userGO showed the highest capacity at a low current, and ex-WS 2 provided a higher reversible capacity. These results showed that the expanded graphene layer is an excellent shield for ex-WS 2 to protect against pulverization, promoting both stability and capacity., Competing Interests: DB was employed by Nanores Sp. z o.o. Sp.k. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Wenelska, Kędzierski, Bęben and Mijowska.)

Surgical face masks waste is a source of microplastics (polymer fibres) and inorganic and organic compounds potentially hazardous for aquatic organisms during degradation in water. The monthly use of face masks in the world is about 129 billion for 7.8 billion people. Therefore, in this contribution the utilization of hazardous surgical face masks waste for fabrication of carbon-based electrode materials via KOH-activation and carbonization was investigated. The micro-mesoporous materials were obtained with specific surface areas in the range of 460 - 969 m 2 /g and a total pore volume of 0.311 - 0.635 cm 3 /g. The optimal sample showed superior electrochemical performance as an electrode material in supercapacitor in the three-electrode system, attaining 651.1F/g at 0.1 Ag -1 and outstanding capacitance retention of 98 % after a test cycle involving 50'000 cycles. It should be emphasized that capacitance retention is one of the most crucial requirements for materials used as the electrodes in the supercapacitor devices. In this strategy, potentially contaminated face masks, common pandemic waste, is recycled into highly valuable carbon material which can serve in practical applications overcoming the global energy crisis. What is more, all microorganisms, including coronaviruses that may be on/in the masks, are completely inactivated during KOH-activation and carbonization., 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 © 2022 Elsevier Inc. All rights reserved.)

Electrochemical exfoliation of nonconductive boron to few-layered borophene is reported. This unique effect is achieved via the incorporation of bulk boron into metal mesh inducing electrical conductivity and opening a venue for borophene fabrication via this feasible strategy. The experiments were conducted in various electrolytes providing a powerful tool to fabricate borophene flakes with a thickness of ~ 3-6 nm with different phases. The mechanism of electrochemical exfoliation of boron is also revealed and discussed. Therefore, the proposed methodology can serve as a new tool for bulk scale fabrication of few-layered borophene and speed up the development of borophene-related research and its potential application., (© 2022. The Author(s).)

Little is known about interactions of non-filamentous, complex-structured lytic phages and free, non-ordered nanoparticles. Emerging questions about their possible bio-sanitization co-applications or predictions of possible contact effects in the environment require testing. Therefore, we revealed the influence of various nanoparticles (NPs; SiO2, TiO2-SiO2, TiO2, Fe3O4, Fe3O4-SiO2 and SiO2-Fe3O4-TiO2) on a T4-like phage. In great detail, we investigated phage plaque-forming ability, phage lytic performance, phage progeny burst times and titers by the eclipse phase determinations. Additionally, it was proved that TEM micrographs and results of NP zeta potentials (ZP) were crucial to explain the obtained microbiological data. We propose that the mere presence of the nanoparticle charge is not sufficient for the phage to attach specifically to the NPs, consequently influencing the phage performance. The zeta potential values in the NPs are of the greatest influence. The threshold values were established at ZP < −35 (mV) for phage tail binding, and ZP > 35 (mV) for phage head binding. When NPs do not meet these requirements, phage−nanoparticle physical interaction becomes nonspecific. We also showed that NPs altered the phage lytic activity, regardless of the used NP concentration. Most of the tested nanoparticles positively influenced the phage lytic performance, except for SiO2 and Fe3O4-SiO2, with a ZP lower than −35 (mV), binding with the phage infective part—the tail.

Heteroatom-doped three-dimensional (3D) porous carbons possess great potential as promising electrodes for high-performance supercapacitors. Inspired by the inherent features of intumescent flame retardants (IFRs) with universal availability, rich heteroatoms and easy thermal-carbonization to form porous carbons, herein we proposed a self-assembling and template self-activation strategy to produce N/P dual-doped 3D porous carbons by nano-CaCO 3 template-assistant carbonization of IFRs. The IFRs-derived carbon exhibited large specific surface area, well-balanced hierarchical porosity, high N/P contents and interconnected 3D skeleton. Benefitting from these predominant characteristics on structure and composition, the assembled supercapacitive electrodes exhibited outstanding electrochemical performances. In three-electrode 6 M KOH system, it delivered high specific capacitances of 407 F g -1 at 0.5 A g -1 , and good rate capability of 61.2% capacitance retention at 20 A g -1 . In two-electrode organic EMIMBF 4 /PC system, its displayed high energy density of 62.8 Wh kg -1 at a power density of 748.4 W kg -1 , meanwhile it had excellent cycling stability with 84.7% capacitance retention after 10,000 cycles. To our best knowledge, it is the first example to synthesize porous carbon from IFRs precursor. Thus, the current work paved a novel and low-cost way for the production of high-valued carbon material, and expanded its application for high-performance energy storage devices., 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 © 2022 Elsevier Inc. All rights reserved.)

In this contribution, the effect of hydrogenation conditions atmosphere (temperature and time) on physicochemical properties and photocatalytic efficiency of graphitic carbon nitride (g-C 3 N 4 , gCN) was studied in great details. The changes in the morphology, chemical structure, optical and electrochemical properties were carefully investigated. Interestingly, the as-modified samples exhibited boosted photocatalytic degradation of Rhodamine B (RhB) with the assistance of visible light irradiation. Among modified gCN, the sample annealed at 500 °C for 4 h (500-4) in H 2 atmosphere exhibited the highest photocatalytic activity-1.76 times higher compared to pristine gCN. Additionally, this sample presented high stability and durability after four cycles. It was noticed that treating gCN with hydrogen at elevated temperatures caused the creation of nitrogen vacancies on gCN surfaces acting as highly active sites enhancing the specific surface area and improving the mobility of photogenerated charge carriers leading to accelerating the photocatalytic activity. Therefore, it is believed that detailed optimization of thermal treatment in a hydrogen atmosphere is a facile approach to boost the photoactivity of gCN.

Here, we report that mesoporous hollow carbon spheres (HCS) can be simultaneously functionalized: (i) endohedrally by iron oxide nanoparticle and (ii) egzohedrally by manganese oxide nanorods (Fe x O y /MnO 2 /HCS). Detailed analysis reveals a high degree of graphitization of HCS structures. The mesoporous nature of carbon is further confirmed by N 2 sorption/desorption and transmission electron microscopy (TEM) studies. The fabricated molecular heterostructure was tested as the anode material of a lithium-ion battery (LIB). For both metal oxides under study, their mixture stored in HCS yielded a significant increase in electrochemical performance. Its electrochemical response was compared to the HCS decorated with a single component of the respective metal oxide applied as a LIB electrode. The discharge capacity of Fe x O y /MnO 2 /HCS is 1091 mAhg -1 at 5 Ag -1 , and the corresponding coulombic efficiency (CE) is as high as 98%. Therefore, the addition of MnO 2 in the form of nanorods allows for boosting the nanocomposite electrochemical performance with respect to the spherical nanoparticles due to better reversible capacity and cycling performance. Thus, the structure has great potential application in the LIB field.

Here, we designed paper sheets coated with chitosan, bacterial cellulose (nanofibers), and ZnO with boosted antibacterial and mechanical activity. We investigated the compositions, with ZnO exhibiting two different sizes/shapes: (1) rods and (2) irregular sphere-like particles. The proposed processing of bacterial cellulose resulted in the formation of nanofibers. Antimicrobial behavior was tested using E. coli ATCC ® 25922™ following the ASTM E2149-13a standard. The mechanical properties of the paper sheets were measured by comparing tearing resistance, tensile strength, and bursting strength according to the ISO 5270 standard. The results showed an increased antibacterial response (assigned to the combination of chitosan and ZnO, independent of its shape and size) and boosted mechanical properties. Therefore, the proposed composition is an interesting multifunctional mixture for coatings in food packaging applications.

Photocatalytic activity of molybdenum disulfide structures with different dimensions (0D, 1D and 2D) functionalized with polymeric carbon nitride (PCN) is presented. MoS 2 nanotubes (1D), nanoflakes (2D) and quantum dots (0D, QDs) were used, respectively, as co-catalysts of PCN in photocatalytic water splitting reaction to evolve hydrogen. Although, 2D-PCN showed the highest light absorption in visible range and the most enhanced photocurrent response after irradiation with light from 460 to 727 nm, QDs-PCN showed the highest photocatalytic efficiency. The detailed analysis revealed that the superior photocatalytic activity of QDs-PCN in comparison with other structures of MoS 2 arose from (i) the most effective separation of photoexcited electron-hole pairs, (ii) the most enhanced up-converted photoluminescence (UCPL), (iii) the highest reactivity of electrons in conduction band. Moreover, a narrowed size of QDs affected shorter diffusion path of charge carriers to active reaction sites, higher number of the sites and higher interfacial area between molybdenum disulfide and PCN., (© 2021 IOP Publishing Ltd.)

Chlorine is found to be a suitable element for the modification of polymeric carbon nitride properties towards an efficient visible-light photocatalytic activity. In this study, chlorine-doped polymeric carbon nitride (Cl-PCN) has been examined as a photocatalyst in the hydrogen evolution reaction. The following aspects were found to enhance the photocatalytic efficiency of Cl-PCN: (i) unique location of Cl atoms at the interlayers of PCN instead of on its π-conjugated planes, (ii) slight bandgap narrowing, (iii) lower recombination rate of the electron-hole pairs, (iv) improved photogenerated charge transport and separation, and (v) higher reducing ability of the photogenerated electrons. The above factors affected the 4.4-fold enhancement of the photocatalytic efficiency in hydrogen evolution in comparison to the pristine catalyst., (Copyright © 2021, Aleksandrzak et al.)

In this study, the core-shell silica nanospheres modified with titanium dioxide were tested in the photocatalytic decomposition of dyes. The presented data underlines the advantages and shortcomings in the potential application of silica-based catalysts to neutralize organic pollutants. During the photocatalytic reaction in distilled water, catalysts showed decreased efficiency due to a carbon layer deposited on its surface. This finding set an additional goal to investigate the possibility of regenerating the photocatalyst. Studies have shown that the catalyst could be successfully reused following the thermal removal of deposited carbon.Furthermore, the reactivated silica-titania catalysts exhibited comparable photocatalytic performance to the newly made nanomaterial. Surprisingly, catalyst application in the river water eventually resulted in the permanent deactivation of silica-titania nanospheres, which was caused by the interchangeable silica dissolution/precipitation process on the surface of the studied nanomaterial. In environmental water, silica dissolves and precipitates on titanium dioxide's surface, blocking the interaction between organic compounds and TiO 2 . The deactivation occurring in the environmental samples is irreversible. In distilled water, the decomposition of organic compounds leads to photocatalysts' deactivation by forming a carbon layer on their surface. Reactivation of the silica-based photocatalyst after distilled water is achievable by annealing at a high temperature. In light of our findings, the combination of the photocatalytic properties of TiO 2 and the silica template shows no prospects in the purification of polluted waste or environmental water., (© 2021 IOP Publishing Ltd.)

Here, we aimed to boost antibacterial performance of cellulose fibers for paper sheet application. Therefore, TiO 2 nanoparticles have been used with controlled loading onto the surface of the fibers. A simple and facile composite preparation route based on ultrasound and mechanical assisted stirring has been developed. We tested cellulose paper enriched by TiO 2 from 1.0 wt% to 8.0 wt%, respectively. Antibacterial performance has been studied against Staphylococcus aureus and Escherichia coli bacteria. Studies showed that all composites exhibit significant capability to reduce living cells of S. aureus and E. coli bacteria at least 60%. The simplicity, low cost, and reproducibility of the prepared method indicates the potential to be scaled up for industrial applications.

Carbon materials derived from zeolitic imidazolate framework-8 (ZIF-8) and composites thereof have been intensively investigated in supercapacitors. The particle size of the used ZIF-8 ranges from dozens of nanometers to several microns. However, the influence of the particle size of ZIF-8 on the capacitive performances is still not clear. A series of ZIF-8 with different particle sizes (from 25 to 296 nm) has been synthesized and carbonized for supercapacitors. Based on TEM, EDX mapping, XRD, Raman, nitrogen adsorption-desorption, XPS, and the results of electrochemical tests, the optimal particle size (≈70 nm) for superior supercapacitor performances in both acidic and alkaline electrolytes has been obtained. This important result provides a significant reference to guide future ZIF-8 related research to achieve the best electrochemical performance., (© 2020 Wiley-VCH GmbH.)

Herein, we report fabrication of MoSe 2 functionalized with bimetal Co/Ni particles, which shows promising electrochemical performance in oxygen and hydrogen evolution reactions (OER and HER) due to its physicochemical properties such as electronic configuration and great electrochemical stability. We propose functionalization with two transition metals, cobalt and nickel, expecting a synergic effect in electrocatalytic activity in a water splitting reaction. These electrocatalytic reactions are essential for efficient electrochemical energy storage. The thin flakes were obtained by exfoliation of bulk molybdenum diselenide. Next, after deposition of metals, precursors were carbonized. Electrochemical data reveal that the presence of Ni and Co particles boosts electrocatalyst performance, providing a great number of active sites due to their conductivity. Interestingly, the material exhibited great evolution potential and good stability in long-term tests., Competing Interests: The authors declare no competing financial interest., (© 2020 American Chemical Society.)

Pseudomonas aeruginosa is a bacterium of high clinical and biotechnological importance thanks to its high adaptability to environmental conditions. The increasing incidence of antibiotic-resistant strains has created a need for alternative methods to increase the chance of recovery in infected patients. Various nanomaterials have the potential to be used for this purpose. Therefore, we aimed to study the physiological response of P. aeruginosa PAO1 to titanium dioxide/silica nanotubes. The results suggest that UV light-irradiated nanomaterial triggers strong agglomeration in the studied bacteria that was confirmed by microscopy, spectrophotometry, and flow cytometry. The effect was diminished when the nanomaterial was applied without initial irradiation, with UV light indicating that the creation of reactive oxygen species could play a role in this phenomenon. The nanocomposite also affected biofilm formation ability. Even though the biomass of biofilms was comparable, the viability of cells in biofilms was upregulated in 48-hour biofilms. Furthermore, from six selected genes, the mexA coding efflux pump was upregulated, which could be associated with an interaction with TiO 2 . The results show that titanium dioxide/silica nanotubes may alter the physiological and metabolic functions of P. aeruginosa PAO1.

The emerging trend towards the reduction of SO 2 in winemaking has created a need to look for alternative methods to ensure the protection of wine against the growth of undesired species of microorganisms and to safely remove wine microorganisms. This study describes the possible application of silica nanospheres as a wine stabilisation agent, with Oenococcus oeni (DSM7008) as a model strain. The experiment was conducted firstly on model solutions of phosphate-buffered saline and 1% glucose. Their neutralising effect was tested under stirring with the addition of SiO 2 (0.1, 0.25, and 0.5 mg/mL). Overall, the highest concentration of nanospheres under continuous stirring resulted in the greatest decrease in cell counts. Transmission electron microscope (TEM) and scanning electron microscopy (SEM) analyses showed extensive damage to the bacterial cells after stirring with silica nanomaterials. Then, the neutralising effect of 0.5 mg/mL SiO 2 was tested in young red wine under stirring, where cell counts were reduced by over 50%. The obtained results suggest that silica nanospheres can serve as an alternative way to reduce or substitute the use of sulphur dioxide in the microbial stabilisation of wine. In addition, further aspects of following investigations should focus on the protection against enzymatic and chemical oxidation of wine.

The renewable energy technologies require electrocatalysts for reactions, such as the oxygen and/or hydrogen evolution reaction (OER/HER). They are complex electrochemical reactions that take place through the direct transfer of electrons. However, mostly they have high over-potentials and slow kinetics, that is why they require electrocatalysts to lower the over-potential of the reactions and enhance the reaction rate. The commercially used catalysts (e.g., ruthenium nanoparticles-Ru, iridium nanoparticles-Ir, and their oxides: RuO 2 , IrO 2 , platinum-Pt) contain metals that have poor stability, and are not economically worthwhile for widespread application. Here, we propose the spinel structure of nickel-cobalt oxide (NiCo 2 O 4 ) fabricated to serve as electrocatalyst for OER. These structures were obtained by a facile two-step method: (1) One-pot solvothermal reaction and subsequently (2) pyrolysis or carbonization, respectively. This material exhibits novel rod-like morphology formed by tiny spheres. The presence of transition metal particles such as Co and Ni due to their conductivity and electron configurations provides a great number of active sites, which brings superior electrochemical performance in oxygen evolution and good stability in long-term tests. Therefore, it is believed that we propose interesting low-cost material that can act as a super stable catalyst in OER.

This study reveals a simple approach to recycle wasted coffee grounds into highly valuable carbon material with superior electrochemical performance. Activated carbon prepared from wasted coffee grounds has been formed via hydrothermal acidic hydrolysis followed by a KOH chemical activation at 800 ∘C. To understand the electrochemical properties of the sample, a set of characterization tools has been utilized: N 2 and CO 2 adsorption-desorption isotherms, thermal gravimetric analysis, Fourier transform infrared spectroscopy, Raman spectroscopy and scanning electron microscopy. The specific surface area obtained from a Brunner-Emmett-Teller (BET) analysis reached 2906±19m2g-1. Prepared sample (designated as ACG-800KOH) was tested as electrode material in an electric double layer capacitor (EDLC) device with ionic liquid PYR13-TFSI as an electrolyte. The EDLC test was conducted at temperatures ranging from 20 to 120 ∘C. The specific material capacitance reached 178 Fg-1 measured at 20 ∘C and 50 A g-1 and was in the range 182 to 285 Fg-1 at the 20 to 120 ∘C temperature range.

Carbon-based supercapacitors have aroused ever-increasing attention in the energy storage field due to high conductivity, chemical stability, and large surface area of the investigated carbon active materials. Herein, eucalyptus-derived nitrogen/oxygen doped hierarchical porous carbons (NHPCs) are prepared by the synergistic action of the ZnCl 2 activation and the NH 4 Cl blowing. They feature superiorities such as high specific surface area, rational porosity, and sufficient N/O doping. These excellent physicochemical characteristics endow them excellent electrochemical performances in supercapacitors: 359 F g -1 at 0.5 A g -1 in a three-electrode system and 234 F g -1 at 0.5 A g -1 in a two-electrode system, and a high energy density of 48 Wh kg -1 at a power density of 750 W kg -1 accompanied by high durability of 92% capacitance retention through 10,000 cycles test at a high current density of 10 A g -1 in an organic electrolyte. This low-cost and facile strategy provides a novel route to transform biomass into high value-added electrode materials in energy storage fields.

Due to the ever-increasing plastic waste causing serious environmental problems, it is highly desirable to recycle it into high-value-added products, such as carbon nanomaterials. However, the traditional catalytic carbonization of hydrocarbon polymers is severely prohibited by the complexity of real-world plastic waste due to the existence of halogen-containing polymers. In this study, through a universal combined template based on magnesium oxide and iron(iii) acetylacetonate (Fe(acac) 3 ), a three-dimensional hollow carbon sphere/porous carbon flake hybrid nanostructure is prepared from carbonization of plastic waste with high yields (>70 wt%). This approach is not only suitable for hydrocarbon polymers, but also for halogen-containing polymers. Interestingly, the obtained advanced carbon framework exhibits excellent performance in lithium-ion batteries (802 mA h g -1 after 500 cycles at 0.5 A g -1 ). The present research paves a new avenue to upcycle plastic waste into a high value-added product.

With the ever-increasing consumption of polyethylene terephthalate (PET) related products, how to recycle the waste PET still remains as a great challenge for the sustainable development. Converting waste PET into porous carbon material has been emerged as a promising way to address this issue. Recently, the microporous carbon derived from waste PET has drawn considerable attention in adsorption field, but its electrochemical application is still impeded by low specific surface area (SSA <1500 m 2  g - 1 ) and small meso-/macropores volume (<0.2 cm 3  g - 1 ). Herein, hierarchical porous carbon (HPC) is successfully prepared from waste PET. The obtained HPC possesses a high SSA (2238 m 2  g - 1 ) and a large meso-/macropores volume (0.51 cm 3  g - 1 ). The formation mechanism of hierarchical porous structure is proposed: co-etching effect of sp 2 /sp 3 hybridized carbon produces micropores and meso-/macropores, respectively. In a three-electrode configuration, HPC based electrode achieves an outstanding capacitance of 413 F g - 1 , while the traditional microporous carbon exhibits a low capacitance of 142 F g - 1 . The fabricated symmetric supercapacitor shows a high energy density of 25 Wh kg - 1 . This work provides a good reference to convert waste plastics into hierarchical porous carbon., 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 © 2020 Elsevier B.V. All rights reserved.)

Polyethylene terephthalate (PET) plastic has been extensively used in our social life, but its poor biodegradability has led to serious environmental pollution and aroused worldwide concern. Up to now, various strategies have been proposed to address the issue, yet such strategies remain seriously impeded by many obstacles. Herein, waste PET plastic was selectively carbonized into three-dimensional (3D) porous carbon nanosheets (PCS) with high yield of 36.4 wt%, to be further hybridized with MnO 2 nanoflakes to form PCS-MnO 2 composites. Due to the introduction of an appropriate amount of MnO 2 nanoflakes, the resulting PCS-MnO 2 composite exhibited a specific capacitance of 210.5 F g -1 as well as a high areal capacitance of 0.33 F m -2 . Furthermore, the PCS-MnO 2 composite also showed excellent cycle stability (90.1% capacitance retention over 5000 cycles under a current density of 10 A g -1 ). The present study paved an avenue for the highly efficient recycling of PET waste into high value-added products (PCSs) for electrochemical energy storage.

In this contribution, the synthesis of the metal-organic framework (MOF) based on lanthanum that exhibits trigonal prism shape is presented. The length of a single side of this structure ranges from 2 to 10 μm. The carbonized lanthanum-based organic framework (CMOF-La) maintained the original shape. However, the lanthanum oxide was reshaped in the form of rods during the carbonization. It resulted in the creation of parallel arranged channels. The unique structure of the carbonized structure motivated us to reveal its adsorption performance. Therefore, the adsorption kinetics of acid red 18 onto a carbonized metal-organic framework were conducted. Various physicochemical parameters such as initial dye concentration and pH of dye solution were investigated in an adsorption process. The adsorption was found to decrease with an increase in initial dye concentration. In addition, the increase in adsorption capacity was noticed when the solution was changed to basic. Optimal conditions were obtained at a low pH. Kinetic adsorption data were analyzed using the pseudo-first-order kinetic model, the pseudo-second-order kinetic model and the intraparticle diffusion model. The adsorption kinetics were well fitted using a pseudo-second-order kinetic model. It was found that the adsorption of anionic dye onto CMOF-La occurs by hydrophobic interactions between carbonized metal-organic framework and acid red 18.

Here, nitrogen-doped carbon nanotubes (CNT-N) were synthesized using exfoliated graphitic carbon nitride functionalized with nickel oxides (ex-g-C 3 N 4 -NixO y ). CNT-N were produced at 900 °C in two steps: (1) ex-g-C 3 N 4 -Ni x O y reduction with hydrogen and (2) ethylene assisted chemical vapor deposition (CVD). The detailed characterization of the produced materials was performed via atomic force microscopy (AFM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The possible mechanism of nanotubes formation is also proposed.

Downsizing well-established materials to the nanoscale is a key route to novel functionalities, in particular if different functionalities are merged in hybrid nanomaterials. Hybrid carbon-based hierarchical nanostructures are particularly promising for electrochemical energy storage since they combine benefits of nanosize effects, enhanced electrical conductivity and integrity of bulk materials. We show that endohedral multiwalled carbon nanotubes (CNT) encapsulating high-capacity (here: conversion and alloying) electrode materials have a high potential for use in anode materials for lithium-ion batteries (LIB). There are two essential characteristics of filled CNT relevant for application in electrochemical energy storage: (1) rigid hollow cavities of the CNT provide upper limits for nanoparticles in their inner cavities which are both separated from the fillings of other CNT and protected against degradation. In particular, the CNT shells resist strong volume changes of encapsulates in response to electrochemical cycling, which in conventional conversion and alloying materials hinders application in energy storage devices. (2) Carbon mantles ensure electrical contact to the active material as they are unaffected by potential cracks of the encapsulate and form a stable conductive network in the electrode compound. Our studies confirm that encapsulates are electrochemically active and can achieve full theoretical reversible capacity. The results imply that encapsulating nanostructures inside CNT can provide a route to new high-performance nanocomposite anode materials for LIB.

Recently great efforts have been focused on converting biowastes into high-valued carbon materials. However, it is still a great challenge to achieve high carbon yield and controllable porous distribution in both industrial and academic research. Inspired by the multi-void structure of waste coffee grounds, herein we fabricated hierarchical porous carbon via the combination of catalytic carbonization and alkali activation. The catalytic carbonization process was applied to obtain well-defined mesoporous carbon with carbon yield as high as 42.5 wt%, and subsequent alkali activation process produced hierarchical porous carbon with ultrahigh specific surface area (3549 m 2 g -1 ) and large meso-/macropores volume (1.64 cm 3 g -1 ). In three-electrode system, the electrode exhibited a high capacitance of 440 F g -1 at 0.5 A g -1 in 6 M KOH aqueous electrolyte, superior to that of many reported biomass-derived porous carbons. In two-electrode system, its energy density reached to 101 Wh kg -1 at the power density of 900 W kg -1 in 1-Ethyl-3-Methylimidazolium Tetrafluoroborate (EMIMBF 4 ). This work provided a cost-effective strategy to recycle biowastes into hierarchical porous carbon with high yield for high-performance energy storage application.

The study presents enhancement of photocatalytic hydrogen generation after metal-organic framework (MOF5) carbonization at 700 °C and its utilization as a co-catalyst of graphitic carbon nitride (gCN). Thermal treatment of MOF5 affected the formation of ZnO nanoparticles which played the role of co-catalyst for H 2 evolution. Moreover, significant band-gap narrowing of MOF5 was observed, which also affected the narrowing of the hybrid band gap. The appropriate conduction band position of the carbonized MOF allowed photogenerated electron transfer from gCN to the carbonized MOF, hence, improving the separation of the charge carriers and reducing the overpotential for H 2 generation. The mechanism of the photocatalytic process was also discussed., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

In this work, few-layered molybdenum disulfide (MoS 2 ) was functionalized with metal oxide (M x O y ) nanoparticles which served as a catalyst for carbon nanotubes (CNT) growth in the chemical vapour deposition (CVD) process. The resulting MoS 2 /M x O y /CNT functionalized nanomaterials were used for flame retarding application in poly(lactic acid) (PLA). The composites were extruded with a twin-screw extruder with different wt% loading of the nanomaterial. Full morphology characterization was performed, as well as detailed analysis of fire performance of the obtained composites in relation to pristine PLA and PLA containing an addition of the composites. The samples containing the addition of MoS 2 /M x O y /CNT displayed up to over 90% decrease in carbon oxide (CO) emission during pyrolysis in respect to pristine PLA. Microscale combustion calorimetry testing revealed reduction of key parameters in comparison to pristine PLA. Laser flash analysis revealed an increase in thermal conductivity of composite samples reaching up to 65% over pristine PLA. These results prove that few-layered 2D nanomaterials such as MoS 2 functionalized with CNT can be effectively used as flame retardance of PLA.

Herein, polystyrene waste was carbonized into mesoporous carbon nanosheets (CNS) using the template method. The pore structure of the obtained CNS was further tuned by KOH activation, resulting in the formation of hierarchical porous carbon sheets with a specific surface area of 2650 m 2 g -1 and a pore volume of 2.43 cm 3 g -1 . Benefiting from these unique properties, in a three electrode system, the hierarchical porous carbon sheets displayed a specific capacitance of 323 F g -1 at 0.5 A g -1 in a 6 M KOH electrolyte, good rate capability (222 F g -1 at 20 A g -1 ) and cycle stability (92.6% of capacitance retention after 10 000 cycles). More importantly, an energy density of 44.1 Wh kg -1 was also displayed with a power density of 757.1 W kg -1 in an organic electrolyte. In this regard, the present strategy demonstrates a facile approach for recycling plastic waste into high value-added products, which will potentially pave the way for the treatment of plastic waste in the future.

Polymeric carbon nitride (PCN), which demonstrates unique properties, has been widely explored, mostly in photocatalysis; however, the evaluation of its biocompatibility is still needed. Herein, the cytocompatibility of PCN with different lateral size distributions (A-PCN with 160 nm, B-PCN with 20 nm, and C-PCN with 10 nm dominating lateral sizes) was investigated. The viability of three cell lines (L929, MCF-7, and HepG2) has been determined using cell counting kit-8 (CCK-8), neutral red uptake (NRU), and lactate dehydrogenase (LDH) leakage assays. It was found that the highest cytotoxicity of PCN was observed for flakes with a lateral size of ∼20 nm (B-PCN) in three cell lines after 48 h of exposition. The uptake process of B-PCN sheets labeled with fluorescein isothiocyanate (FITC) by cells was also the most effective. Confocal laser scanning microscopy and atomic force microscopy revealed the nanomaterial distribution throughout the cytoplasm and perinuclear region. The results demonstrated the correlation among size, internalization process, and cytocompatibility of the tested polymeric carbon nitride structures.

The fabrication of conventional or biodegradable polymers with improved thermal and fire-resistant properties is an important task for their successful application in various branches of the industry. In this work, few-layered molybdenum disulfide was functionalized with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and introduced into polyethylene and poly(lactic acid) matrixes. The obtained polyethylene composite samples displayed improved thermal stability, significant reduction in CO emissions, improved fire-resistant properties, and over 100% increases in thermal conductivity. Poly(lactic acid) composites displayed less impressive results, but have managed to improve some values, such as CO emissions, peak heat release rate, and total heat release in comparison to pristine polymer.

Porous graphene flakes (PGFs) with controllable pore sizes are selectively prepared through self-assembly of Fe 3 O 4 nanoparticles on organic modified montmorillonite combined with carbonization and subsequent annealing treatment. The resulting PGFs with a thickness of 5 nm have a specific surface area of 337 m 2 /g, pore volume of 0.66 cm 3 /g, and mean pore diameter of 15 nm. Due to their unique porous flake structures, PGFs show an impressive rate performance in lithium-ion batteries, especially at high current densities (238 mA h/g at 10 C) as well as long-term stability in comparison to the commercial graphite (55 mA h/g at 10 C). Therefore, PGFs with their key structural properties serve as ideal candidates as electrode components in lithium-ion batteries and show great potential application in other energy storage fields.

To induce the water solubility of hexagonal boron nitride (h-BN), we exfoliated and functionalized bulk h-BN with hydroxyl groups (h-BN-OH-n). Short-term studies showed that h-BN-OH-n induced low cytotoxicity in different models: insect haemocytes (in vivo), human erythrocytes and mouse fibroblasts (in vitro). We also demonstrated that Alexa Fluor 647-h-BN-OH-n administered topically to the insects passed through the cuticle barrier and was phagocytosed by haemocytes. Nanoflakes did not affect the haemocyte cell membrane and did not interfere with the phagocytosis of latex beads. Long-term immunoassays showed that h-BN-OH-n, despite not inducing haemocytotoxicity, impaired nodulation, the most important cellular immune response in insects. The haemocytes exposed to h-BN-OH-n and then to bacteria differed in morphology and adhesiveness from the haemocytes exposed only to bacteria and exhibited the same morphology and adhesiveness as the control haemocytes. The h-BN-OH-n-induced decrease in nodulation can therefore result from the reduced ability of haemocytes to recognize bacteria, migrate to them or form microaggregates around them, which can lead to dysfunction of the immune system during pathogen infection. Long-term in vivo studies with animal models are still necessary to unambiguously confirm that h-BN is biocompatible and useful for application as a platform for drug delivery or for bioimaging.

Carbon-based supercapacitors have attracted considerable academic and practical interest due to their advantages of low cost, high power density, and superior durability. Herein, we report the facile synthesis of hierarchical porous carbon sheets (HPCSs) featuring a high specific surface area (2788 m 2 g -1 ), derived from pyrrole through a combination of MgO template carbonization and KOH activation. The hierarchical pores with the co-existence of micropores and mesopores were obtained in the HPCSs. Benefiting from the high surface area, well-balanced pore size distribution as well as high conductivity, the prepared HPCSs exhibited a high gravimetric specific capacitance of 226.4 F g -1 at a scan rate of 1 mV s -1 in the electrolyte of 1 M H 2 SO 4 in the two-electrode configuration. Moreover, the excellent electrochemical long-cycle stability has been demonstrated by 10 000 cycles of rapid charging-discharging at 10 A g -1 with a capacitance retention of 97.3%. The electrochemical performance clearly indicates the promising potential of using HPCSs as electrode materials for supercapacitors.

Nitrogen-doped hierarchical porous carbon (CN x -Co) samples embedded with cobalt nanoparticles are selectively prepared with polyethylenimine (PEI) as both the carbon and nitrogen sources. By processing at different temperature, CN x -Co-800 and CN x -Co-1000 are selectively prepared and the materials exhibit excellent electrocatalytic activity in the oxygen reduction reaction (ORR). The ORR measurements show that sample processed at the higher temperature delivers better performance due to the larger Co and graphitic nitrogen concentrations. CN x -Co-1000 also shows more tolerance against methanol crossover and outstanding durability towards ORR, making it a promising Pt-free electrocatalyst for ORR under alkaline conditions. The method demonstrated here is a general strategy to prepare other metal or metal alloy/porous carbon hybrid materials., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Carbon nanotubes (CNTs) have been of great interest because of their unique electrical, structural, and mechanical properties. Many methods for obtaining CNTs are known. Chemical vapor deposition (CVD) has been recognized as the most popular and practical synthetic method for obtaining CNTs, with high purity, high yield, and low cost. Catalyst components are usually transient metals such as Fe, Co, and Ni, and hydrocarbons are used as a feedstock for the CNT synthesis. The metal particles are supported on the inorganic porous materials, such as alumina (Al 2 O 3 ), silica (SiO 2 ), magnesia (MgO), zeolite, and mesoporous silica. In this work, we propose a new platform for the deposition of metal nanoparticles and the growth of CTs. Molybdenum disulfide (MoS 2 ) has gained much attention in the material fields. The principal aim of the present work is to compare the synergetic effect of MoS 2 and CTs and to investigate the possibility of using the material in various fields. The obtained material was tested for its use in fire retardation. We compared the effect of adding bulk MoS 2 and MoS 2 /CTs into the polymer matrix., Competing Interests: The authors declare no competing financial interest.

In our study we prepared MOF-5 derived carbon to reveal the thermodynamics of CO 2 absorption processes in great detail. Porous carbon material was prepared from a metal-organic framework (MOF-5) via carbonization at 1000 °C. The obtained structure consists only of carbon and exhibits a BET specific surface area, total pore volume and micropore volume of 1884 m 2 g -1 , 1.84 cm 3 g -1 and 0.59 cm 3 g -1 , respectively. Structural analysis allowed the assumption that this material is an ideal candidate for efficient CO 2 absorption. The CO 2 uptake was 2.43 mmol g -1 at 25 °C and 1 bar. Additionally, the absorption over a wide range of temperatures (25, 40, 60, 80 and 100 °C) and pressures (in range of 0-40 bar) was investigated. It is shown that the CO 2 absorption isotherm fits a multitemperature Sips model. The calculated Sips equation parameters allows the isosteric heat of adsorption to be obtained. The isosteric heat of adsorption for CO 2 decreased substantially with an increase in surface coverage by gas molecules. This indicates a negligible intermolecular interaction between CO 2 molecules. A decrease in the isosteric heat of adsorption with surface coverage is a result of the disappearance of favourable adsorption sites., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The synthesis of interconnected nanoporous carbon (NPC) material from direct annealing of ultra-small Al-based metal-organic complex (Al-MOC) has been demonstrated. NPC presents a large accessible area of 1,054 m²/g, through the Methylene Blue (MB) adsorption method, which is comparable to the high specific surface area (SSA) of 1,593 m²/g, through an N₂ adsorption/desorption analysis. The adsorption properties and mechanisms were tested by various dye concentrations, pH, and temperature conditions. The high MB accessible area and the good electrical conductivity of the interconnected NPC, led to a large specific capacitance of 205 F/g, with a potential window from 0 to 1.2 V, in a symmetric supercapacitor, and a large energy density of 10.25 Wh/kg, in an aqueous electrolyte, suggesting a large potential in supercapacitors., Competing Interests: The authors declare no conflict of interest.

Recently, sustainable development and serious energy crisis called for appropriate managements for the large number of municipal and industrial waste plastics as well as the development of low-cost, advanced materials for energy storage. However, the complexity of waste plastics significantly hampers the application of ever used methods, and little attention is paid to the utilization of waste plastics-derived carbon in energy storage. Herein, porous carbon nanosheets (PCNSs) was produced by catalytic carbonization of "real-world" mixed waste plastics on organically-modified montmorillonite (OMMT) and the subsequent KOH activation. PCNSs was featured on hierarchically micro-/mesoporous structures with the pore size distribution centered on 0.57, 1.42 and 3.63 nm and partially exfoliated graphitic layers, and showed a high specific surface area of 2198 m 2  g -1 and a large pore volume of 3.026 cm 3  g -1 . Benefiting from these extraordinary properties, PCNSs displayed a superior performance for supercapacitors with high specific capacitances approaching 207 and 120 F g -1 at a current density of 0.2 A g -1 in aqueous and organic electrolytes, respectively. Importantly, when the current density increased to 10 A g -1 , the specific capacitances remained at 150 F g -1 (72.5%) and 95 F g -1 (79.2%) in aqueous and organic electrolytes, respectively. The outstanding rate capability of PCNSs was in sharp contrast to the performance of traditional activated carbons. This work not only provides a potential way to recycle mixed waste plastics, but also puts forward a facile sustainable approach for the large-scale production of PCNSs as a promising candidate for supercapacitors., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Due to white pollution related environmental concern and sustainable development requirement, it is desirable to recycle the widely used plastic wastes into products with commercial value, such as high-valued carbon materials which can be applied in electrochemical fields. In this work, porous carbon flakes (PCFs) are produced by direct pyrolysis of polystyrene waste through template method. Furthermore, manganese dioxide (MnO 2 ) nanosheets are selectively deposited on the surface of resultant PCFs to form hybrid (PCF-MnO 2 ). Because of the large specific surface area (1087 m 2 /g) and high conductivity of PCFs, native high specific capacity of MnO 2 , and positive synergistic interaction between PCF and MnO 2 , the resulting hybrid materials show an ultrahigh capacitance of 308 F/g at 1 mV/s and 247 F/g at 1 A/g in LiCl electrolyte, and excellent cycle stability of 93.4% capacitance retention over 10,000 cycles at 10 A/g in symmetric supercapacitor device. This work demonstrates a convenient method for the preparation of cost-effective and high-performance electrode material for electric capacitor. More importantly, it provides a potential way to recycle polystyrene waste into high-valued product in large-scale with disposing of polymeric waste to alleviate environmental concerns., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Enhancing the photocatalytic performance of graphitic carbon nitride (g-C 3 N 4 , GCN) and titanium dioxide (TiO 2 ) has played a key role in the energy and environmental protection research community. Therefore, it is necessary to explore the synergy of both materials with carbon nanostructures for photocatalysis. Among the variety of carbon materials, graphene flakes and nanotubes, as nanoadditives to improve electron charge transfer and the optical absorption behavior in the visible-light region, have been widely explored. Thus, flake-like (2 D) and tubular (1 D) carbon structures in composition with GCN and/or TiO 2 are reviewed, as are their photocatalytic response. Current trends clearly indicate that this type of molecular hybrids can be efficiently exploited in this field. This Minireview covers state-of-the-art research over the period of 2015 to 2018., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Functional carbon materials have been fabricated through simple and effective catalytic carbonization with waste coffee grounds (CGs) as carbon precursor and FeCl 3 as catalyst. The effect of FeCl 3 loading and carbonization temperature on carbon yield was investigated. The morphology and structure of as-synthesized carbons was characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and nitrogen isothermal adsorption/desorption measurement, respectively. Furthermore, the carbon materials showed high efficiency for the removal of methylene blue (MB, 653.6 mg g -1 ), methyl orange (MO, 465.8 mg g -1 ) and rhodamine B (RB, 366.1 mg g -1 ). More importantly, the carbon was magnetic, so it can be easily separated by a magnet and reused multiple times. This work not only exploited a low-cost and large-scale preparation method to synthesize functional carbon materials from bioresources, but also provided an eco-friendly and effective adsorbent in water purification applications., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Although many biosilicification methods based on cationic linear α-poly -l- lysine for synthesis of polylysine/silica hybrids have been investigated, these methods tend to rely on the counteranions, added catalysts, and complex synthesis process. To explore a simple and efficient biosilicification method, in this work, branched poly-l-lysine (BPL) is used as both a catalyst to hydrolyze tetraethoxysilane (TEOS) and an in situ template to direct silicic acids forming polylysine/silica hybrids in one-pot mode. The catalysis of BPL to hydrolyze TEOS results from the abundant hydrogen bonding (as the active site) to increase the nucleophilicity of BPL. Meanwhile, the hydrogen bonding is also found to be the key factor determining the self-assembly of BPL. During biosilicification, owing to self-assembly of BPL molecules, BPL would form spherical particles by keeping a random-coil conformation or form lamellar structures by undergoing a conformational transition from a random-coil to β-sheet construction. As a result, polylysine/silica hybrids with tunable topological structures are synthesized using aggregated BPLs as templates after the hydrolysis of TEOS. This finding of applying BPL to fulfill the biosilicification procedure without counteranions and added catalysts would enable a better understanding of the polypeptide-governed biosilicification process and pave a way for fabricating complex inorganic architectures applicable to silica transformational chemistry., Competing Interests: The authors declare no competing financial interest.

Electrodes from carbonized Zn₄O(1,4-benzodicarboxylic acid) (MOF-5) structures were prepared successfully via evaporating the solvent with a poly(vinylidene fluoride) (PVDF) binder. The solvent used for a nanocomposite cast was easily removed. Such an elegant method for preparing electrodes provides a facile, cost-effective, and void/cracking-free nanocomposite distribution on the current collector. The highly porous nanoparticles containing pure carbon attach well to the PVDF membrane which results in an increased active surface area of the electrode to 847 m²/g. The electrochemical analysis shows that the best weight ratio of CMOF-5 to PVDF equals 85:15, 80:20, and 75:25, respectively. The specific capacitance of these samples is 218 F/g, 210 F/g, and 180 F/g, correspondingly. An additional advantage of the electrode prepared from the carbonized MOF-5 is the possibility to synthesis MOF structures from recovered substrates used in its synthesis (distilled N,N-Dimethylformamide DMF and terephthalic acid recovered from polyethylene terephthalate waste). We will demonstrate this in this contribution as well. Furthermore, the carbonized MOF-5 can be recovered from the spent electrode and reused again in the electrochemical device.

Here, we report a facile route for obtaining carbon spheres with fully tunable shell thickness. Using a hard template in chemical vapor deposition (CVD), hollow carbon spheres, solid carbon spheres, and intermediate structures can be obtained with optimized process time. The resulting carbon spheres with particle diameters of ~400 nm, as well as a controllable shell thickness from 0 to 70 nm, had high Brunauer⁻Emmett⁻Teller (BET) specific surface area (up to 344.8 m²·g -1 ) and pore volume (up to 0.248 cm³·g -1 ). The sphere formation mechanism is also proposed. This simple and reproducible technique can deliver carbon materials for various applications, e.g., energy storage and conversion, adsorption, catalytic, biomedical, and environmental applications.

Hexagonal boron nitride is often referred to as white graphene. This is a 2D layered material, with a structure similar to graphene. It has gained many applications in cosmetics, dental cements, ceramics etc. Hexagonal boron nitride is also used in medicine, as a drug carrier similar as graphene or graphene oxide. Here we report that this material can be exfoliated in two steps: chemical treatment (via modified Hummers method) followed by the sonication treatment. Afterwards, the surface of the obtained material can be efficiently functionalized with gold nanoparticles. The mitochondrial activity was not affected in L929 and MCF-7 cell line cultures during 24-h incubation, whereas longer incubation (for 48, and 72 h) with this nanocomposite affected the cellular metabolism. Lysosome functionality, analyzed using the NR uptake assay, was also reduced in both cell lines. Interestingly, the rate of MCF-7 cell proliferation was reduced when exposed to h-BN loaded with gold nanoparticles. It is believed that h-BN nanocomposite with gold nanoparticles is an attractive material for cancer drug delivery and photodynamic therapy in cancer killing.

In this work, exfoliated tungsten disulfide (WS 2 ) functionalized with metal oxides as a filler of polyethylene (PE) was used. An efficient exfoliation procedure resulted in the synthesis of 7-9 layered flakes of WS 2 . Flakes of exfoliated WS 2 were functionalized by iron oxide and nickel oxide nanoparticles, respectively. The nanomaterials were mixed with polyethylene by extrusion. Methods such as Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), X-Ray Diffraction (XRD) or Thermogravimetric Analysis (TGA) were used to characterize the materials. Flame retardant properties were investigated by microcalorimetry. Comparing the obtained values of heat released during combustion, it can be observed that the addition of fillers reduces flammability significantly compared to neat polyethylene. It is revealed that this composite can provide a certain physical barrier and inhibit the diffusion of heat and gaseous products during combustion. Thermogravimetric analysis of composites showed increased thermal stability with addition of nanofillers and reduction of carbon monoxide generation in the whole range of the nanofiller addition (from 0.5 to 2 wt% in PE). Results suggested that the composite with Ni 2 O 3 could endow the best flame retardance for PE. The peak heat release rate of this sample with 2 wt% nanofiller was reduced to 792 W g -1 (1216 W g -1 for PE), and the total heat release was decreased to 39 kJ g -1 (47 kJ g -1 for PE). A very significant increase in thermal conductivity for all composites was observed as well., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Nanoparticles were proposed as antibacterial cement admixtures for the production of cement-based composites. Nevertheless, the standards for evaluation of such admixtures still do not indicate which model organisms to use, particularly in regard to the further application of material. Apart from the known toxicity of nanomaterials, in the case of cement-based composites there are limitations associated with the mixing and dispersion of nanomaterials. Therefore, four nanooxides (Al₂O₃, CuO, Fe₃O₄, and ZnO) and seven microorganisms were tested to initially evaluate the applicability of nanooxides in relation to their further use in cement-based composites. Studies of nanoparticles included chemical analysis, microbial growth kinetics, 4- and 24 h toxicity, and biofilm formation assay. Nanooxides showed toxicity against microorganisms in the used concentration, although the populations were able to re-grow. Furthermore, the effect of action was variable even between strains from the same genus. The effect of nanoparticles on biofilms depended on the used strain. Gathered results show several problems that can occur while studying nanoparticles for specific further application. Proper protocols for nanomaterial dispersion prior the preparation of cement-based composites, as well as a standardized approach for their testing, are the fundamental issues that have to be resolved to produce efficient composites., Competing Interests: The authors declare no conflict of interest.