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Herein, a series of Fe-based catalysts have been designed and prepared by grinding a mixture of MIL-88d and melamine, and then the mixture was followed by pyrolysis. An unusual Fe/Fe3C-activated site is uniformly encapsulated in the N-doped carbon tubes obtained by pyrolysis of the film-like nanocrystals of MIL-88d. Experimental characterizations and theoretical calculations demonstrate that the surface N sites can effectively trap the nitrobenzene and aniline by their phenyl groups with the formation of three C–N bonds that made the catalyst exhibit excellent catalytic activity (turnover frequencies of ≤11268 h–1 calculated on the basis of nitrobenzene) and chemoselectivity for the reduction of nitro derivatives under facile conditions.

A double in situ process, combination of injection chemical vapour deposition and biomineralisation, was used to fabricate carbon nanotubes (CNTs)-reinforced apatite composite coatings on carbon/ca...

Hydroxyapatite (HA) coatings were synthesised on carbon/carbon composites (C/C) with a graphene oxide (GO) interlayer. The morphology and microstructure of the GO interlayer and the HA coating were researched. The effect of applying GO interlayer on the morphology and microstructure of HA coating was investigated. The in vitro bioactivity of HA coating for C/C with GO interlayer was investigated. The results indicated that the GO interlayer was spread on the surface of C/C substrate uniformly. The morphology of the HA coating on original C/C was uneven composed of HA grains with a length 10–50 μm and nanoplate structure HA grains. The morphology of the HA coating with GO interlayer was uniform composed of single nanoplate structure HA grains. The formation process of the HA coating on C/C with GO interlayer was discussed. In addition, the simulated body fluid immersion tests showed that the HA coating with GO interlayer exhibited good bioactivity.

A dicalcium phosphate dehydrate (DCPD) coating was successfully fabricated on carbon fiber with in-situ grown graphene (IGN) interlayer. The obtained coating was analyzed using XRD, SEM, XPS, Raman, TEM and Thermo-gravimetric analysis(TGA). The in-vitro bioactivity of the obtained coating was investigated by simulated body fluid (SBF) immersion test. The results showed that the IGN interlayer grew homogenously on the carbon fiber with a wavy shape. The IGN interlayer was 40–90 nm in length and less than 10 nm in thickness. The DCPD exhibited a flake shape with a size of 10–50 nm. The IGN could bond with the DCPD tightly and form a uniform distribution within the DCPD coating. TGA test revealed that the carbon fiber with IGN interlayer was more effective for DCPD attachment and deposition than pure carbon fiber. The SBF tests showed that the DCPD coating could induce the formation of a cloud shaped apatite layer. The DCPD coated carbon fiber with IGN interlayer would be possible for potential application in tissue engineering.

A silicon-substituted hydroxyapatite (Si-HA) coating for SiC-coated carbon/carbon composites has been prepared by pack cementation and electrochemical deposition. The morphology, microstructure and in-vitro bioactivity of the Si-HA/SiC double-layer coatings were investigated. Results showed that the SiC inner-layer exhibited high crystallinity. The Si-HA outer-layer had a smaller crystal size than pure hydroxyapatite (HA). Simulated body fluid (SBF) immersion tests showed that the Si-HA coating was uniformly covered by a layer of apatite after 7 days of immersion, while the apatite layer formed on the HA coating was inhomogeneous. This work demonstrates that the Si-HA coating may have better bioactivity than a HA coating and shows promise for the potential application as bioactive coating.

Based on the spatial distribution of ancient rocks and zircons, three ancient terranee older than ca. 2.6 Ga have recently been identified in the North China Craton, namely the Eastern, Southern, and Central Ancient Terranee. The Eastern Ancient Terrane is the best studied and understood of the three ancient terranes. It has a long geological history back to ca. 3.8 Ga ago and includes the areas of Anshan-Benxi, eastern Hebei, eastern Shandong and western Shandong. In Anshan-Benxi, several different types of 3.8 Ga rocks were discovered together with 3.1–3.7 Ga rocks, whereas 2.9–3.0 Ga K-rich granites and 2.5 Ga syenogranite occur on larger scales. In eastern Hebei, 3.0–3.4 Ga rocks and older detrital and xenocrystic zircons were identified. In eastern Shandong, there are a large volumes of 2.7 Ga and 2.9 Ga rocks. In western Shandong, early Neoarchean (2.6–2.7 Ga) intrusive and supracrustal rocks are widely distributed. Whole-rock Nd and zircon Hf isotope data suggest that both mantle additions and crustal recycling played important roles within the Eastern Ancient Terrane during almost every tectono-magmatic event. Most BIFs in the North China Craton are late Neoarchean in age and are distributed on continental crust along the western margin of the Eastern Ancient Terrane, probably suggesting that a stable environment was one of the key factors for the formation of large-scale BIFs.

A multi-layer coating composed of SiC inner-layer and Mg and F co-substituted hydroxyapatite/chitosan hybrid out-layer for carbon fibers has been synthesized using a combination method of chemical vapor deposition, electrochemical deposition and ion exchange method. The morphology, microstructure and in-vitro bioactivity of the multi-layer coating are analyzed. The results show that the SiC inner-layer exhibits a squamous shape. Mg and F co-substituted hydroxyapatite/chitosan hybrid out-layer covers the SiC inner-layer coated carbon fiber entirely and uniformly with a flat structure. The multi-layer coating could induce the precipitation of particle-shaped apatite crystals with Ca/P molar ratios of 1.34–1.51 on its surface in simulated body fluid. The multi-layer SiC/Mg and F co-substituted hydroxyapatite/chitosan coated carbon fibers should have potential application for tissue engineering.

Carbon nanotubes/carbon fibers hybrid materials (CCF) were used as templates to deposit carbonate-containing hydroxyapatite (CHA) by ultrasound-assisted electrodeposition method. The morphology and microstructure of CCF and CHA on CCF were characterized by X-ray diffraction, scanning electron microscopy, Transmission electron microscopy, Energy dispersive X-ray spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and Thermogravimetric analysis. The results showed that the CCF was composed of carbon fibers and in situ grown carbon nanotubes. The carbon nanotubes were grown along the radial direction of the carbon fibers with a straight morphology and exhibited a loose structure. The CHA enwrapped the in situ grown carbon nanotubes of CCF, then infiltrated into the loose structures of the carbon nanotubes and finally covered the CCF entirely with a particle shape. By thermogravimetric analysis, the CHA on CCF displayed more deposition weight than that on carbon fibers without carbon nanotubes.

Double-layer TC4/Sr substituted hydroxyapatite bioactive coatings were applied on carbon/carbon composites using a combination method of magnetron sputtering and ultrasound-assisted electrochemical deposition (UED). Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were adopted to investigate the morphology, microstructure and composition of the coating. The in vitro bioactivity of the coating was investigated using simulated body fluid (SBF) and cell culture tests. The results showed that the double-layer TC4/Sr substituted hydroxyapatite bioactive coatings were successfully applied on carbon/carbon composites. The deposition of TC4 inner layer was induced by the arrangement of the carbon fiber in carbon/carbon composites. The Sr substituted hydroxyapatite out layer formed a porous three-dimensional network structure with a pore size ranging from 15 nm to 400 nm after UED for 1 min and then exhibited a dense structure after UED for 2 h. The SBF immersion tests showed that the double-layer TC4/Sr substituted hydroxyapatite coating could induce the formation of a uniform apatite layer in SBF. The cell culture experiment showed that the cells were favorably elongated and flattened with plenty of filopods and microvilli on the double-layer coating, exhibiting excellent cell activity and cell proliferation behavior.

Na, F and carbonate multi-substituted hydroxyapatite (NFCH) with nanobelt shape has been synthesized using a combined method of ultrasound-assisted electrochemical deposition and ion exchange. The morphology, microstructure and in-vitro bioactivity of the NFCH are analyzed. The results show that the nanobelt-shaped NFCH are 5–40 nm in thickness, 250–700 nm in width and tens of micrometers in length. The nanobelt-shaped NFCH is oriented randomly and interlocked with each other on carbon/carbon composite substrates. The nanobelt-shaped NFCH could induce the precipitation of apatite layers with Ca/P molar ratios of 1.34–1.51 on its surface in simulated body fluid, exhibiting excellent in-vitro biocompatibility. The nanobelt-shaped NFCH should have potential application as reinforcement phase for bioactive coatings or as scaffold for tissue engineering.

A Na and Si co-substituted carbonated hydroxyapatite (NaSiCH) coating was applied on carbon nanotubes coated carbon/carbon composites using an ultrasound-assisted electrochemical deposition (UED) method. The morphology and microstructure of the coating were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The in vitro bioactivity of the coating was investigated by examining the ability of apatite formation on its surface in simulated body fluid (SBF). The results showed that the carbon nanotubes coated carbon/carbon composites could provide a porous surface structure for the deposition of NaSiCH. After the UED process, the Na could replace Ca in the structure of hydroxyapatite. The Si could enter into the hydroxyapatite structure in the form of SiO 4 4− groups that are combined with the CO 3 2− to substitute the PO 4 3− groups. The NaSiCH coating was successfully applied on carbon nanotubes coated carbon/carbon composites. The NaSiCH crystals first enwrapped the carbon nanotubes and then infiltrated into the porous structure of the carbon nanotubes. Finally the NaSiCH coating formed a homogeneous coverage, exhibiting a belt shape with a width of 150–350 nm and a thickness less than 50 nm. The SBF tests showed that the NaSiCH coating could induce the formation of a uniform apatite layer with a wavy shape. In conclusion, NaSiCH offers great potential as a coating material for future medical application.