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A single step fast track method is proposed to determine melamine based on strong hydrogen bonding between exocyclic amine group in melamine moiety and hydroxyl group of tannic acid (TA); acting as reducing and functionalizing agent for synthesis of gold nanoparticles (Au NPs). The proposed strategy is facile and highly time saving; as the detection of melamine with labelfree gold nanoparticles was accomplished within five minutes. The colorimetric probe exhibits high detection limit of 8 nM for melamine determination in raw milk, which is very low as compared to other capping ligands employed for Au NPs such as borohydride, citrate and 3,5-dihydroxybenzoic acid. The results show a highly sensitive linear range (0.03–2.5 μM) between absorption ratio and concentration of melamine with a correlation coefficient of 0.991. Proposed methodology is proven effective for on-site screening without using costly instrumentation.

Herein, we demonstrated poly(diaryloxy)phosphazene (PDPP) which has inherent thermal stability and flame retardancy, is used as a matrix material for the fabrication of novel thermal conductive composites (TCCs) with variety of thermal conductive fillers including aluminum oxide (Al2O3), boron nitride (BN), silicon carbide (SiC) and expended graphite (EG) with different particle size and volume fraction by special processing method. Thermogravimetric analysis (TGA) and limit oxygen index (LOI) results indicated that the TCCs own excellent thermal stability and flame retardancy. SEM analyses of the as-prepared materials showed high orientation degree of flake-like fillers after processing. The thermal conductivity (TC) of the TCCs measurements implied that the EG is the most effective filler to enhance the TC. TC measured in-plane direction reaches a highest value 7.05 Wm−1 K−1 for EG filled samples, which is times higher than PDPP matrix. This work explored a great potential of polyphosphazenes as a matrix material for TCCs.

A novel idea has been developed to realize the formation of heteroatoms doped carbon materials by exploiting a precursor of a single compound, polyphosphazene, for supercapacitor applications. Heteroatoms (N, P, O) containing polymer, poly(diaryloxyphosphazene) (PDPP) was synthesized by the substitution reaction of linear polydichlorophosphazene (PDCP) with sodium phenolate. After carbonization of PDPP, a nanoporous carbon materials doped with N, P and O were obtained. The BET studies had shown that the surface area of this activated carbon material reached up to 1798 m2 g−1 with pore volume up to 0.91 cm3 g−1. When applied as supercapacitor electrodes, this heteroatoms doped carbon material exhibited a specific capacitance of 105 F g−1 at 0.3 A g−1 in a two-electrode cell (up to 329 F g−1 at 0.5 A g−1 in a three-electrode cell) and better rate performance with 55.2% of maintenance from 0.3 to 10 A g−1 in a two-electrode cell (63.8% of maintenance from 0.5 to 50 A g−1 in a three-electrode cell). Owing to the large surface area, adequate pore volume, stable cycling performance and good rate capabilities of our synthesized material, it has potential application as supercapacitor electrodes.

This research describes the synthesis of a novel type of poly [cyclotriphosphazene-co-1,3,5-triol nitrobenzene] (PCTNB) microspheres with uniform size and diameter of more than 2 μm having well characterization. These microspheres are further used to wrap the CNTs by a facile route using template based non-covalent method to form PCTNB@CNTs composite. This composite is further well analyzed before it is subjected to pyrolysis. The direct carbonization of the PCTNB@CNTs is performed at 600 °C at a rate of 5 °C/min under N2 atmosphere to render the N, P, O doped carbonized PCTNB@CNTs having enhanced electronic features to be applied as an ORR electrocatalysts in fuel cells accompanied by TEM, XPS, Raman, FT-IR, TGA and BET analyses. Here, we have designed a metal-free, N, P, O doped (C-PCTNB@CNTs) electro-catalyst which exhibit significantly high ORR performance in acidic PEM cells showing much higher onset potential of (0.94 V) and half-wave potential of (0.85 V) with electron transfer number (n) 3.9 at 0.4–0.7 V as compared to other non-metallic electro-catalysts. Thus, (C-PCTNB@CNTs) is a metal-free, methanol tolerant carbon-based ORR catalyst, and it opens up new avenues for clean energy generation for affordable and durable fuel cells.

Owing to high-energy density of rechargeable lithium-ion batteries (LIBs), they have been investigated as an efficient electrochemical power sources for various energy applications. High theoretical capacities of tin oxide (SnO 2 ) anodes have led us a path to meet the ever-growing demands in the development of high-performance electrode materials for LIBs. In this paper, a facile approach is described for the synthesis of porous low-dimensional nanoparticles and nanorods of SnO 2 for application in LIBs with the help of Tween-80 as a surfactant. The SnO 2 samples synthesized at different reaction temperatures produced porous nanoparticles and nanorods with average diameters of ~7–10 nm and ~70–110 nm, respectively. The SnO 2 nanoparticle electrodes exhibit a high reversible charge capacity of 641.1 mAh/g at 200 mA/g after 50 cycles, and a capacity of 340 mAh/g even at a high current density of 1000 mA/g during the rate tests, whereas the porous nanorod electrodes delivers only 526.3 mAh/g at 200 mA/g after 50 cycles and 309.4 mAh/g at 1000 mA/g. It is believed that finer sized SnO 2 nanoparticles are much more favorable to trap more Li + ion during electrochemical cycling, resulting in a large irreversible capacity. In contrast, rapid capacity fading was observed for the porous nanorods, which is the result of their pulverization resulting from repeated cycling.

Ferrocenylphosphazenes have been attracting increasing attention for their special properties and potential applications. We describe here a new high-throughput synthesis of cross-linked poly(cyclotriphosphazene-co-bis(aminomethyl)ferrocene) microspheres via the polycondensation of hexachlorocyclotriphosphazene and 1,1′-di(aminomethyl)ferrocene by precipitation polymerization. The mean diameter of the microsphere varies from 0.3 to 1.3 μm, depending on the concentrations of both monomers in a calculated molar ratio. The morphology and structure of microspheres were characterized by FT-IR, SEM, EDX and TEM analyses. TG analysis demonstrated their superior thermal stability owing to the presence of high cross-linked bonding. Magnetic measurements revealed that the microspheres are superparamagnetic with a saturation magnetization of 23.7 emu g−1. The electrochemical properties of the microspheres were also examined by cyclic voltammetry and the results showed a single reversible redox process. Room-temperature photoluminescence spectra of the microspheres exhibited a strong emission peak at 405 nm. The Brunauer−Emmett−Teller (BET) pore-size distribution maximum is about 37.4 nm that leads to efficient adsorption behavior. These microspheres were found to be an excellent high capacity adsorbent for the selective cationic dye (methylene blue) removal from contaminated water. The changes in parameters, such as contact time, temperature and concentration of adsorbate were examined to study their influence on adsorption capacity. The results obtained suggest that the microspheres can effectively adsorb methylene blue with an adsorption capacity increasing from 480 to 2160 mg g−1 as the initial concentration was increased from 50 to 400 mg L−1. Owing to the superior properties and novelty of the synthesized hybrid microspheres, they can possibly be used in several applications, e.g., in catalysis, bio-assays, and electric and magnetic devices.

The design of a three-dimensional structure for an Ir-based catalyst offers a great opportunity to improve the electrocatalytic performance and maximize the use of the precious metal. Herein, a novel wet chemical strategy is reported for the synthesis of an IrRuMn catalyst with a sphere structure and porous features. In the synthetic process, the combined use of citric acid and formamide is requisite for the formation of the sphere structure. This method leads to a favorable 3D IrRuMn sphere structure with many fully exposed active sites. Furthermore, an alloying noble metal, such as Ir or Ru, with the transition metal leads to enhanced oxygen evolution reaction (OER) activity. The doping of a transition metal, such as Mn, is an interesting example, because it exhibits stability and activity in both acidic and alkaline media. For the OER, the IrRuMn sphere catalyst exhibits an overpotential of 260 mV at a current density of 10 mA cm-2 in strongly acidic 0.1 m HClO4 , which is superior to that of a commercial IrO2 /C catalyst. This approach provides a novel way to synthesize an Ir-based multimetallic spherical electrocatalyst, which exhibits exceptional efficiency for the acidic OER. It will pave the way for new approaches to the practical utilization of PEM electrolyzers.

Finding a reliable synthetic route of anode materials for lithium ion batteries (LIBs) is a pivotal area of research. Here, a facile method is developed to synthesize porous nanowires and thorn like copper oxide (CuO) using a non-ionic surfactant, Tween-80 for LIBs. Tween-80 serves as an effective template in directing the growth of nanowires and thorn-like CuO, in both low and high temperatures hydrothermal synthesis procedures. The products are characterized by XRD, FTIR, TGA, SEM, TEM, XPS and BET. When evaluated as anode material for LIBs, CuO nanowires exhibited better capacity retention with a record high reversible capacity of over 506.6 mAh g −1 for up to 50 cycles as compared to thorn-like CuO which delivers reversible capacity of only 430.4 mAh g −1 . The better electrochemical performance is attributed to the porous nature of the products and this simple synthetic route makes CuO nanowires a potential future anode material for LIBs.

The ever increasing growth and interest in the field of material science for the production of functionalized polymer microspheres with tunable size is of pivotal importance. This research describes the one pot method for the facile synthesis of fluorescent active poly[cyclotriphosphazene-co-1,3,5-tri(4-hydroxyphenyl)benzene] (PCTHB) microspheres with the desired structural morphology obtained by the reaction of 1,3,5-tri(4-hydroxyphenyl)benzene (HPB) with hexachlorocyclotriphosphazene (HCCP) through the precipitation polymerization. The sizes of the microspheres can be tuned by changing the amount of both the cross linkers in a calculated molar ratio. The mean diameter of the microspheres varies in the range of 0.5–1.1 μm. The morphology and structure of PCTHB microspheres were characterized by FT-IR, solid state 31P NMR, SEM, EDX-mapping and TEM analyses. A mechanism for the preparation of PCTHB microspheres has been proposed, in which HPB plays a crucial role, as its presence gives the final desired shape to the microspheres. The concentration of HBP beyond 2 mM has produced irregular morphology of the microspheres. Room-temperature photoluminescence spectra of the PCTHB microspheres reveal a strong emission peak at 372 nm. These fluorescent polymer PCTHB microspheres can be developed with great ease as compared to those with the aid of quantum dots and dyes. Due to these superior properties and novelty of our synthesized material, it can be used as a potential biomaterial for several applications such as diagnostics, photocatalysis, biological imaging, organic or inorganic analysis, and light emitting diodes.

A hierarchical excavated iron-nitrogen codoped mesoporous carbon (Ex-FeN-MC) electrocatalyst has been successfully synthesized by pyrolysis of the unique ureidopyrimidinone containing organic precursor MAMIS by using silica as the mesoporous template and iron nitrate as the source of iron. The selected organic precursor has multifunctionalities with diverse distribution of nitrogen and oxygen species which constitute interesting features to prepare the Ex-FeN-MC electrocatalyst. The as-prepared Ex-FeN-MC material shows unexpectedly higher catalytic activities towards ORR/OER performances with an overpotential of 250 mV for OER in alkaline solution at a current density of 10 mA cm−2, while the ORR activity is almost similar to that of commercial Pt/C. It is believed that the excellent electrochemical performance results from the synergic contribution of the hierarchical uniform mesoporous structure, evenly distributed iron nanoparticles and high density of Ex-FeN-MC catalytically active sites. The presence of the hierarchical uniform mesoporous structure considerably accelerates the mass transfer and efficiently promotes the full utilization of active sites. Furthermore, it also possesses amorphous carbon in coexistence with lattice graphitic carbon which also enhanced the ORR/OER performances. Our research findings can surely provide a new insight to design highly active ORR/OER electrocatalysts by utilizing more novel organic precursors to provide interesting characteristics to electrocatalysts, as well as open up a route for constructing unique multifunctional materials with mesoporous architectures for electrocatalysis and supercapacitor applications.