Comparative study on the performance of co-extruded hollow fiber solid oxide fuel cell fuelled with hydrogen and methane

Journal of Solid State Electrochemistry - In this study, the effects of two fuel types, i.e., hydrogen and methane on the electrochemical performance of the co-extruded triple layer hollow fiber,...     

Nitrogen-Linked Hexaazatrinaphthylene Polymer as Cathode Material in Lithium-Ion Battery

Nitrogen-linked hexaazatrinaphthylene polymer ( N²-HATN ) as organic cathode material with low HOMO–LOMO gap was synthesized and was observed to possess reversible high capacity and unexpected long-term cycling stability. The pre-treated N²-HATN and pRGO combination demonstrated good structure compatibility and the resultant cathode exhibited a constant increment of capacity during the redox cycles. The initial capacity at 0.05 A g⁻¹ was 406 mA h⁻¹ g⁻¹, and increased to 630 mA h⁻¹ g⁻¹ after 70 cycles. At 0.5 A g⁻¹ discharging rate, the capacity increased from an initial value of 186 mA h⁻¹ g⁻¹ to 588 mA h⁻¹ g⁻¹ after 1600 cycles. The pseudocapacitance-type behavior is postulated to be attributed to the structure compatibility between the active material and pRGO.     

Gas Phase Preparation of the Elusive Monobridged Ge(μ-H)GeH Molecule through Nonadiabatic Reaction Dynamics

The hitherto elusive monobridged Ge(μ-H)GeH (X¹A′) molecule was prepared in the gas phase by bimolecular reaction of atomic germanium with germane (GeH₄). Electronic structure calculations revealed that this reaction commenced on the triplet surface with the formation of a van der Waals complex, followed by insertion of germanium into a germanium-hydrogen bond over a submerged barrier to form the triplet digermanylidene intermediate (HGeGeH₃); the latter underwent intersystem crossing from the triplet to the singlet surface. On the singlet surface, HGeGeH₃ predominantly isomerized through two successive hydrogen shifts prior to unimolecular decomposition to Ge(μ-H)GeH isomer, which is in equilibrium with the vinylidene-type (H₂GeGe) and dibridged (Ge(μ-H₂)Ge) isomers. This reaction leads to the formation of cyclic dinuclear germanium molecules, which do not exist on the isovalent C₂H₂ surface, thus deepening our understanding of the role of nonadiabatic reaction dynamics in preparing nonclassical, hydrogen-bridged isomers carrying main group XIV elements.     

Impact of polyvinylpyrrolidone and quantity of silver nitrate on silver nanoparticles sizing via solvothermal method for dye-sensitized solar cells

The multiple sizing of silver nanoparticles (AgNPs) were synthesized from the miscible compound of ethylene glycol (EG), polyvinylpyrrolidone (PVP) and silver nitrate (AgNO3) via the solvothermal method. During the synthesis, the PVP-AgNO3 was contemplated as a paramount parameter. Using the simple method of solvothermal, the sizing of AgNPs was easily controlled in accord with the augmentation of PVP-AgNO3 at secured and moderate temperature. In regards to the sizing of AgNPs, the presence of minimum agglomeration, the absorption capability and chemical structures were highlighted through a series of verification includes ultraviolet–visible (UV–Vis) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM) analysis. The effectiveness of the synthesized AgNPs was further investigated and compared with the commercial AgNPs by incorporating the AgNPs into titanium dioxide (TiO2) semiconductor film-based dye-sensitized solar cells (DSSCs). Results signified that the spherical AgNPs with produced sizing within the range of 19.6 to 45.2 nm were greatly impacting by tunable quantities of PVP-AgNO3, which was validated in the forms of linear equations. A larger size promotes a slower nucleation rate that conduces agglomeration. In opposition to this, the smallest size of AgNPs develops a faster formation rate of Ag ions into AgNPs, inducing the deterrent of agglomeration in light of notable particle dispersion. The power conversion efficiency (PCE) contributed by the incorporation of synthesized AgNPs into TiO2 is also 41.2% higher than that of the commercial AgNPs-TiO2. This is because the synthesized AgNPs provides less agglomeration which led to a better surface plasmonic effect towards the nanoparticles.     

Experimental and Mathematical Modelling of Factors Influencing Carbon Dioxide Absorption into the Aqueous Solution of Monoethanolamine and 1-Butyl-3-methylimidazolium Dibutylphosphate Using Response Surface Methodology (RSM)

This paper investigated the solubility of carbon dioxide (CO₂) in an aqueous solution of monoethanolamine (MEA) and 1-butyl-3-methylimidazolium dibutylphosphate ((BMIM)(DBP)) ionic liquid (IL) hybrid solvents. Aqueous solutions of MEA-(BMIM)(DBP) hybrid solvents containing different concentrations of (BMIM)(DBP) were prepared to exploit the amine’s reactive nature, combined with the IL’s non-volatile nature for CO₂ absorption. Response surface methodology (RSM) based on central composite design (CCD) was used to design the CO₂ solubility experiments and to investigate the effects of three independent factors on the solubility of CO₂ in the aqueous MEA-(BMIM)(DBP) hybrid solvent. The three independent factors were the concentration of (BMIM)(DBP) (0–20 wt.%), temperature (30 °C–60 °C) and pressure of CO₂ (2–30 bar). The experimental data were fitted to a quadratic model with a coefficient of determination (R²) value of 0.9791. The accuracy of the developed model was confirmed through additional experiments where the experimental values were found to be within the 95% confidence interval. From the RSM-generated model, the optimum conditions for CO₂ absorption in aqueous 30 wt% MEA-(BMIM)(DBP) were 20 wt% of (BMIM)(DBP), a temperature of 41.1 °C and a pressure of 30 bar.     

Enhanced Recovery and Purification of P(3HB-co-3HHx) from Recombinant Cupriavidus necator Using Alkaline Digestion Method

A simple, efficient and economical method for the recovery of P(3HB-co-3HHx) was developed using various chemicals and parameters. The initial content of P(3HB-co-3HHx) in bacterial cells was 50?C60?wt%, whereas the monomer composition of 3HHx used in this experiments was 3?C5?mol%. It was found that sodium hydroxide (NaOH) was the most effective chemical for the recovery of biodegradable polymer. High polyhydroxyalkanoate purity and recovery yield both in the range of 80?C90?wt% were obtained when 10?C30?mg/ml of cells were incubated in NaOH at the concentration of 0.1?M for 60?C180?min at 30?°C and polished using 20?% (v/v) of ethanol.     

Synthesis,Characterization and X-ray Structure of N-(4-bromobutanoyl-N’-(2-3- and 4-methylphenyl)thiourea

N-4-(bromobutanoyl)-N'-(o-, m- and p-tolyl)thioureas 3a, 3b and 3c respectively, were synthesized by the reaction of 4-bromobutanoylisothiocyanate with p-, m- and o-toludine. The products were characterized by IR, and NMR spectroscopic techniques. The two carbonoylthiourea isomers N-(4-bromobutanoyl)-N'-(3-methylphenyl)thiourea(3b) and N-(4-bromobutanoyl)-N'-(4-methylphenyl)thiourea(3c) were obtained in crystalline form by recrystallization from DMSO. Xray crystallographic studies showed that both compounds 3b and 3c crystallize in triclinic system with space group of P1. The molecules adopt trans-cis configuration with respect to the positions of 4-bromobutanoyl and tolyl groups respectively, against the thiono C=S bond across their C–N bonds. The configuration is attributed by the intrahydrogen bond between the carbonyl oxygen and amide hydrogen atoms. Both crystal structures are stabilized by N–H···S intermolecular hydrogen bonds to form dimers and arranged along the b axis.     

Nickel nanoparticles generated by pulsed laser ablation in liquid CO2

Research on Chemical Intermediates - Nickel nanoparticles with various structures were synthesized by a pulsed laser ablation process in liquid CO2 at 17 °C and 5.2 MPa. A...     

Chemical Diversity and Biological Activity of Secondary Metabolites Isolated from Indonesian Marine Invertebrates

Marine invertebrates have been reported to be an excellent resource of many novel bioactive compounds. Studies reported that Indonesia has remarkable yet underexplored marine natural products, with a high chemical diversity and a broad spectrum of biological activities. This review discusses recent updates on the exploration of marine natural products from Indonesian marine invertebrates (i.e., sponges, tunicates, and soft corals) throughout 2007–2020. This paper summarizes the structural diversity and biological function of the bioactive compounds isolated from Indonesian marine invertebrates as antimicrobial, antifungal, anticancer, and antiviral, while also presenting the opportunity for further investigation of novel compounds derived from Indonesian marine invertebrates.