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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.)

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.

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 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.)

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.)

In this contribution, we present the synthesis and carbonization mechanism of metal-organic frameworks (MOFs) based on cobalt and terephthalic acid, with detailed attention to the carbonization mechanism of cobalt-based organic frameworks. The evolution of the unique morphology of carbonized cobalt organic frameworks induced by temperature allows the synthesis of a hybrid of multi-layered carbon structures with metal and metal oxide nanoparticles placed between them. The formation of various phases and diameter distributions of cobalt nanoparticles resulted in the partial degradation of carbon structure and exfoliation. Presented data describe the connection between cobalt particle oxidation and carboreduction with the phenomenon of metal particle agglomeration. The presented study allows us to select carbonization conditions in order to obtain the desired cobalt crystalline structure on the graphene flakes from cobalt-based MOFs.

Porous Pd@m-C/SiO 2 nanopeapods are prepared by a nanoconfinement method. The Pd nanoparticles show high efficiency and stability in chemical reactions such as reduction of nitrobenzene by H 2 and reduction of NO by NH 3 . The high catalytic activity is attributed to the unique peapod structure, mesoporous wall, and large specific surface area on Pd@m-C/SiO 2 rendering the Pd nanoparticles highly active in chemical reactions.

The synthesis of designed nanostructures is an ultimate target of nanomaterial science. Here, silica spheres with nanoholes have been selectively prepared. Coating the necklace-like structured and magnetic nanoparticles along carbon nanotubes, which is an essential step of the simple synthetic procedure of silica hollow spheres, led to the formation of silica hollow spheres with controllable sized nanoholes in their shell walls. The synthesized hollow spheres with nanoholes would be a good support for loading large molecules, e.g. drugs and proteins.