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Titanium nitride and vanadium nitride–carbon-based composite systems, TiN/C and VN/C, were prepared using a new synthesis method based on the thermal decomposition of titanyl tetraphenyl porphyrin (TiOTPP) and vanadyl tetraphenyl porphyrin (VOTPP), respectively. The structure of the TiN/C and VN/C composite materials, as well as their precursors, were characterized using Fourier Transformed Infrared Spectroscopy, X-Ray diffraction (XRD), X-Ray energy dispersive (EDS) and X-Ray photoelectron spectroscopy (XPS). Morphologies of the TiN/C and VN/C composites were examined by means of scanning electron (SEM) and transmission electron (TEM) microscopy. The synthesis of the non-metalated tetraphenyl porphyrin, the titanium, and vanadium tetraphenyl porphyrin complexes were confirmed using FTIR. The thermal decomposition of the titanium and vanadium tetraphenyl porphyrin complexes produced the respective metal nitride encapsulated in a carbon matrix; this was confirmed by XRD, SEM, TEM, and XPS. From the XRD patterns, it was determined that the TiN and VN were presented in cubic form with expected space group FM-3M and 1:1 (metal:N) stoichiometry. The XPS results confirmed the presence of both TiN and VN in the carbon matrix without metal carbides. The SEM and TEM results showed that both TiN and VN nanoparticles formed small clusters throughout the carbon matrix; the EDS results revealed a uniform composition. The synthesis method presented in this work is novel and serves as an effective means to produce TiN and VN NPs with good structure and morphology embedded in a carbon matrix. 

Graphene and graphene oxide have shown good antibacterial activity against different bacterial species due to their unique physicochemical properties. Graphene oxide (GO) has been widely used to load metallic and metal oxide nanoparticles (NPs) to minimize their surface energy during processing and preparation, hence reducing their aggregation. In this work, GO was effectively synthesized and coated with different concentrations of zinc hydroxide Zn (OH)x using the precipitation method to prepare a GO/Zn (OH)x hybrid composite. The Zn (OH)x NPs and GO/Zn (OH)x nanocomposites were synthesized and characterized using various methods such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Coating GO with Zn (OH)x NPs resulted in improved aggregation of Zn (OH)x NPs as well as enhanced antibacterial activity of GO against Gram-positive and Gram-negative bacteria. Additionally, the effect of Zn (OH)x coating on the antibacterial properties of the GO/Zn (OH)x composite was systematically investigated. The synergistic effects of GO and Zn (OH)x NPs resulted in enhanced antibacterial properties of the composites compared to the pristine GO material. In addition, increasing the Zn (OH)x wt. % concentration led to an increased inhibition zone of the GO/Zn (H)x composite against Bacillus megaterium and E. coli bacteria. 

The present work focuses on the synthesis of a vanadium nitride (VN)/carbon nanocomposite material via the thermal decomposition of vanadyl phthalocyanine (VOPC). The morphology and chemical structure of the synthesized compounds were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), Fourier transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoemission spectroscopy (XPS). The successful syntheses of the VOPC and non-metalated phthalocyanine (H2PC) precursors were confirmed using FTIR and XRD. The VN particles present a needle-like morphology in the VN synthesized by the sol-gel method. The morphology of the VN/C composite material exhibited small clusters of VN particles. The XRD analysis of the thermally decomposed VOPC indicated a mixture of amorphous carbon and VN nanoparticles (VN(TD)) with a cubic structure in the space group FM-3M consistent with that of VN. The XPS results confirmed the presence of V(III)-N bonds in the resultant material, indicating the formation of a VN/C nanocomposite. The VN/C nanocomposite synthesized through thermal decomposition exhibited a high carbon content and a cluster-like distribution of VN particles. The VN/C nanocomposite was used as an anode material in LIBs, which delivered a specific capacity of 307 mAh g−1 after 100 cycles and an excellent Coulombic efficiency of 99.8 at the 100th cycle. 

This work focuses on the synthesis of titanium nitride–carbon (TiN–carbon) composites by the thermal decomposition of a titanyl phthalocyanine (TiN(TD)) precursor into TiN. The synthesis of TiN was also performed using the sol-gel method (TiN(SG)) of an alkoxide/urea. The structure and morphology of the TiN–carbon and its precursors were characterized by XRD, FTIR, SEM, TEM, EDS, and XPS. The FTIR results confirmed the presence of the titanium phthalocyanine (TiOPC) complex, while the XRD data corroborated the decomposition of TiOPC into TiN. The resultant TiN exhibited a cubic structure with the FM3-M lattice, aligning with the crystal system of the synthesized TiN via the alkoxide route. The XPS results indicated that the particles synthesized from the thermal decomposition of TiOPC resulted in the formation of TiN–carbon composites. The TiN particles were present as clusters of small spherical particles within the carbon matrix, displaying a porous sponge-like morphology. The proposed thermal decomposition method resulted in the formation of metal nitride composites with high carbon content, which were used as anodes for Li-ion half cells. The TiN–carbon composite anode showed a good specific capacity after 100 cycles at a current density of 100 mAg−1. 

In the present study, the removal of both As(III) and As(V) from aqueous solutions using synthesized ZnO nanomaterials was achieved. The ZnO nanomaterial was synthesized using a precipitation technique and characterized using XRD, SEM, and Raman spectroscopy. XRD confirmed the ZnO nanoparticles were present in the hexagonal wurtzite structure. SEM of the particles showed they were aggregates of triangular and spherical particles. The average nanoparticle size was determined to be 62.03 ± 4.06 nm using Scherrer’s analysis of the three largest diffraction peaks. Raman spectroscopy of the ZnO nanoparticles showed only ZnO peaks, whereas the after-reaction samples indicated that As(V) was present in both As(V)- and As(III)-reacted samples. The adsorption of the ions was determined to be pH-independent, and a binding pH of 4 was selected as the pH for reaction. Batch isotherm studies showed the highest binding capacities occurred at 4 °C with 5.83 mg/g and 14.68 mg/g for As(III) and As(V), respectively. Thermodynamic studies indicated an exothermic reaction occurred and the binding of both As(III) and As(VI) took place through chemisorption, which was determined by the ΔH values of −47.29 and −63.4 kJ/mol for As(V) and As(III), respectively. In addition, the change in Gibbs free energy, ΔG, for the reaction confirmed the exothermic nature of the reaction; the spontaneity of the reaction decreased with increasing temperature. Results from batch time dependency studies showed the reaction occurred within the first 60 min of contact time. 

The cold sintering process (CSP) is a low-temperature consolidation method used to fabricate materials and their composites by applying transient solvents and external pressure. In this mechano-chemical process, the local dissolution, solvent evaporation, and supersaturation of the solute lead to “solution-precipitation” for consolidating various materials to nearly full densification, mimicking the natural pressure solution creep. Because of the low processing temperature (<300°C), it can bridge the temperature gap between ceramics, metals, and polymers for co-sintering composites. Therefore, CSP provides a promising strategy of interface engineering to readily integrate high-processing temperature ceramic materials (e.g., active electrode materials, ceramic solid-state electrolytes) as “grains” and low-melting-point additives (e.g., polymer binders, lithium salts, or solid-state polymer electrolytes) as “grain boundaries.” In this minireview, the mechanisms of geomimetics CSP and energy dissipations are discussed and compared to other sintering technologies. Specifically, the sintering dynamics and various sintering aids/conditions methods are reviewed to assist the low energy consumption processes. We also discuss the CSP-enabled consolidation and interface engineering for composite electrodes, composite solid-state electrolytes, and multi-component laminated structure battery devices for high-performance solid-state batteries. We then conclude the present review with a perspective on future opportunities and challenges.