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This work reports the use of M-BDC (M = Cu, Mn, Ni, and Zr) MOFs for glucose sensing by surface plasmon resonance (SPR) methods. The sensitivity is in the order of Zr-BDC > Cu-BDC > Mn-BDC > Ni-BDC > bare Au chip.

Au nanoparticles encapsulated in UiO-66 MOF were hybridized with Au films to generate strong coupling between their plasmon resonances. Glucose absorbing to UiO-66 modulates the local permittivity, which can be detected by the SPR sensor.

Metal-organic frameworks (MOFs) are porous crystalline materials that consist of metal ions bind to organic ligands as linkers by coordination covalent bonds. MOF properties, such as the presence of open metal sites, large surface area, high porosity, high thermal stability, tunable structure, and feasibility in modification are controlled and determined by metal cations, organic linkers, and applied synthetic method. Reductive electrosynthesis is a popular and interesting MOF synthetic method on the surface of conductive substrates. This method is based on electroreduction of oxoanions to generate hydroxide anions that lead to selective deposition of MOFs on conductive surfaces to form a thin MOFs film. The applied potentials during electrosynthesis affect the properties and applications of the produced MOFs. Here, Cu-based MOFs with the type of CuBTC (H3BTC: 1,3,5-benzenetricarboxylic acid) known as HKUST-1 films were synthesized using different cathodic potentials and time, at room temperature, on the surface of brass. The reductive electrosynthesis was found to be fast and mild for preparing HKUST-1. This method allows direct surface modification which in turn affect the HKUST-1 applications as electrode material for electrochemical sensing such as glucose.

Two-dimensional metal–organic frameworks (2D MOFs) are an attractive platform to develop new kinds of catalysts because of their structural tunability and large specific surface area that exposes numerous active sites. In this work, we report a general method to synthesize benzene dicarboxylic acid (BDC)-based MOFs with hierarchical 3D morphologies composed of 2D nanosheets or nanoplates. In our proposed strategy, acetonitrile helps solvate the metal ions in solution and affects the morphology, while polyvinylpyrrolidone (PVP) serves as a shape-control agent to assist in the nucleation and growth of MOF nanosheets. PVP also acts as a depletion agent to drive the assembly of the hierarchical sheet/plate-like M-BDC under solvothermal conditions. Further, we also demonstrate the flexibility of the proposed method using numerous coordinating metal ions (M = Cu, Mn, Ni, and Zr). The potential of these MOFs for electrochemical glucose sensing is examined using the hierarchical sheet-like Ni-BDC MOF as the optimum sample. It drives the electrocatalytic oxidation of glucose over a wide range (0.01 mM to 0.8 mM) with high sensitivity (635.9 μA mM−1 cm−2) in the absence of modification with carbon or the use of conductive substrates. It also demonstrates good selectivity with low limit of detection (LoD = 6.68 μM; signal/noise = 3), and fast response time (, This work reports the general fabrication of hierarchical sheet/plate-like M-BDC MOFs for electrochemical non-enzymatic glucose sensing.

Sulfated silica (SO4/SiO2) and nickel impregnated sulfated silica (Ni-SO4/SiO2) catalysts have been successfully carried out for the conversion of ethanol into diethyl ether (DEE) as a biofuel. The aims of this research were to study the effects of acidity on the SO4/SiO2 and Ni-SO4/SiO2 catalysts in the conversion of ethanol into diethyl ether. This study focuses on the increases in activity and selectivity of SiO2 with the impregnation of sulfate and Ni metal, which had good activity and acidity and were less expensive. The SO4/SiO2 catalysts were prepared using TEOS (Tetraethyl Orthosilicate) as a precursor and sulfuric acid with various concentrations (1, 2, 3, 4 M). The results showed that SO4/SiO2 acid catalyst treated with 2 M H2SO4 and calcined at 400 °C (SS-2-400) was the catalyst with highest total acidity (2.87 g/mmol), while the impregnation of Ni metal showed the highest acidity value at 3%/Ni-SS-2 catalyst (4.89 g/mmol). The SS-2-400 and 3%/Ni-SS-2 catalysts were selected and applied in the ethanol dehydration process into diethyl ether at temperatures 175, 200, and 225 °C. The activity and selectivity of SS-2-400 and 3%/Ni-SS-2 catalysts shown the conversion of ethanol reached up to 9.54% with good selectivity towards diethyl ether liquid product formation.

Methanol is a simple alcohol compound which is known very volatile and to be toxic inside of human’s body. Therefore, it is necessary to develop a sensor that is capable to detect the methanol vapor in indoor air. Zn-based MOF is a polymeric coordination compound made up of ZnxOyCz inorganic cluster as the secondary building unit (SBU) and benzene dicarboxylate as the bridging ligand and formed bulky and porous material. In this research, composites of manganese oxide (MnO2) and Zn-based MOF are synthesized and characterized as material sensor for its capability towards sensing of methanol gas. Diffractogram of PXRD reveals that the synthesized Zn-MOF is crystalline and become more amorphous due to MnO2 addition. The composite was made into pellets and measured of its resistivity. The addition of MnO2 to the Zn-MOF lowered the resistivity of the Zn-MOF and the composite was found to be sensitive towards methanol vapor.

A zirconia-based catalyst with controlled crystalline phases is synthesized through a simple thermal decomposition of a parent UiO-66 single precursor. The introduction of Ti(IV) and Hf(IV) cation into the Zr(IV) framework has been successfully obtained to tune the photocatalytic activity over methyl orange (MO) solution. Their resulting crystalline phases, morphologies, elemental analysis, band gap values, surface area, and photocatalytic degradation study over MO dye are presented and discussed. The tetragonal zirconia (t-ZrO2) catalyst exhibits the highest photocatalytic activity with 89% decoloration efficiency under UV irradiation (λ = 254 nm) for 300 min compared to m-ZrO2 (67%), the mixed phases (t-ZrO2 and m-ZrO2), as well as the synthesized mixed oxides ZrO2-MO2 (M = Ti or Hf), where the photocatalytic activities are 74% and 63%, respectively. This result is on par with commercially available anatase TiO2 and other reported t-ZrO2 catalysts.

This SO4/TiO2 catalyst as a heterogeneous acidic catalyst was synthesized in various concentrations of H2SO4. The activity and selectivity of the SO4/TiO2 catalyst on the dehydration reaction of ethanol to diethyl ether were studied as well. The SO4/TiO2 was prepared from TiO2 powder by wet impregnation method with a various aqueous solution of H2SO4 (1; 2; 3 M H2SO4) and calcination temperature (400, 500, and 600 °C) to obtain a catalyst with optimum acidity. The catalysts were characterized using FTIR, XRD, SEM-EDX, SAA, TGA/DSC, and acidity test gravimetrically with ammonia. The liquid product of DEE was analyzed by gas chromatography (GC) to analyze the selectivity of the catalyst. The catalyst TS-3-400 had the highest activity and selectivity in the dehydration reaction of ethanol to diethyl ether at a temperature of 225 °C, with a conversion of 51.83% and a DEE selectivity of 1.72%.

Ni-Fe alloy used as cathode in alkaline water electrolysis to reduce energy consumption. Effectiveness of this alloy in hydrogen evolution reaction (HER) influenced by its intrinsic properties. Deposit of Ni-Fe alloy was prepared on stainless steel substrate by direct current (DC) electrodeposition. The phase of deposits characterized by Powder X-ray Diffraction (PXRD) with values of 2θ at 44.03 and 51.28 according to CIF reference of Ni3Fe crystalline phase. The effectiveness of Ni-Fe alloy simply measured by volume of hydrogen gas produced from alkaline water electrolysis reaction using Hofmann voltameter. The rate of production hydrogen gas of Ni3Fe alloy in 0.10 M KOH at room temperature was 0.010 cc/minutes at 1.5 V and 3 mA. It has better electrocatalytic activity than nickel deposit to produce hydrogen gas in alkaline water electrolysis. Hofmann voltameter is simple tool can applied to introduce electrocatalytic subject in chemistry learning.

The diffusion coefficients of both iron(II)-bipyridine ([Fe(bpy) 3 ] 2+ ), ruthenium(II)-bipyridine ([Ru(bpy) 3 ] 2+ ) are reported in five of different imidazolium-based ionic liquids (ILs) and iron(II)-phenanthroline ([Fe(phen) 3 ] 2+ ), ruthenium(II)-phenanthroline ([Ru(phen) 3 ] 2+ ) in one of imidazolium-based ionic liquid, using cyclic voltammetry and chronoamperometry at microdisc electrodes. Activation energies of diffusion, E D , are calculated for each system. Diffusion coefficient ratios between oxidation and reduction species for both complexes were found to be close to 1. Plots of diffusion coefficients versus inverse viscosity deviate from expected linearity, especially for ILs with different kind of anions, suggesting that anions of the ILs contribute to the values of diffusion coefficients. E D for both complexes in ILs are found slightly larger compared to the activation energies of viscous flow ( E η ) for the corresponding IL, indicating that the viscosity is not the only factor determining the diffusion of the complexes. Furthermore, the hydrodynamic radius of complexes in ILs were estimated based on the diffusion coefficient values. They are found to be independent of temperature and ILs viscosity.

EFFECT OF CRYSTALLINITY TO OVERPOTENTIAL ON Ni 3 Fe ALLOY AS ELECTROCATALYST IN HYDROGEN EVOLUTION REACTION. Ni-Fe alloys can be used as electrocatalyst for the hydrogen evolution reaction (HER) in an alkaline solution. HER consumed highly energy and overpotential driven. The overpotential value corresponding to the electron transfer in reaction can be affected either by metal combination or alloy as a cathode. Ni₃Fe alloy had been successfully synthesized by the electrodeposition method using direct-current (DC) on a 304 L type stainless steel substrate. The modified Watts bath deposition was used NiCl 2 ·6H 2 O and FeCl 3 ·6H 2 O as precursors of the alloy. The optimum conditions of the reaction were obtained at pH of the solution is 2.20±0.02 with 25 mA/cm² current density at 55 °C for 160 minutes. Ni₃Fe alloy was characterized by Powder X-ray Diffraction (PXRD), Energy-Dispersive X-ray Spectroscopy (EDX), and Scanning Electron Microscopy (SEM). The electrocatalytic property of Ni 3 Fe alloy was electrochemically measured in 1 M KOH solution by polarization method using a Tafel plot with a scanning rate of 1 mV/s. As a result, the mass ratio of Ni²+ /Fe³+ in bath deposition influenced the electrocatalytic property of Ni₃Fe alloy. Ni₃Fe alloy with a higher crystallinity lowered the overpotential value of HER up to 67% compared to Ni metal.

Porous metal-organic frameworks of Zr 6 O 4 (OH) 4 clusters connected by organic linkers of 1,4-benzenedicarboxylate (UiO-66) and biphenyl-4,4′-dicarboxylate (UiO-67) were prepared using a solvothermal method and used as efficient catalysts for acetalization of benzaldehydes with alcohols. UiO-66 showed better catalytic activity than UiO-67, (i.e. 91% vs 86%) when the catalyst was employed in the benzaldehyde acetalization in methanol for an hour at r.t. (28 °C). UiO-66 was further explored as the catalyst to observe effects of catalyst concentrations, alcohols, bulkier benzaldehydes, and recyclability. The performance of other catalysts, including the MOF precursor, was also examined to compare the activity and to explain the importance of a MOF structure. Relative Lewis acidity of Zr in UiO-66 and UiO-67 was achieved by natural bond orbital (NBO) analysis using DFT/B3LYP method. It was found that accessibility of substrates to internal active sites might play a dominant role than the Lewis acidity of Zr-MOFs.

Electrolytes system plays an important part in Lithium Ion Batteries (LIBs) due to its role in lithium ion (Li+) transport between anode and cathode. Commercial LIBs use organic carbonates-based electrolytes system, but these electrolytes are flammable and volatile. For these reasons, replacement with non-flammable, non-volatile and high conductive compounds become recent research focus. Owing to the excellent properties, ILs are expected to cover the limitation of the organic-based electrolytes system in LIBs. The conductivity of electrolytes system which consists of dimethyl carbonate (DMC)/diethyl carbonate (DEC) (1:1, v/v) as organic solvent (OS) and imidazolium-based ILs is measured at various temperatures. Furthermore, the thermal stability of the electrolytes and the redox properties of lithium ion in IL-based electrolytes system are also investigated. [bmim][BF4]-based electrolyte yields a conductivity of ~13 mS cm−1 at 20 °C which is 10,000 times higher than DMC/DEC based only. Thermal analysis shows that the IL-based electrolytes decompose at 360 °C, much higher than the organic-based only (∼110 °C). Cyclic voltammetry measurement of the ILs-based electrolytes with [bmim][BF4] : DEC: DMC (3:1:1) + LiBF4 0.2 M compositions displays reversible redox reaction. The presence of [bmim][BF4] affects the redox reaction of Li+ ion, in both current and potential. Based on these results, a mixture of ILs and organic solvent has a potential as a new electrolytes system in the next LIBs.

The influence of multiple additions of two oxides, Cr 2 O 3 and Nb 2 O 5 , as additives on the hydrogen sorption kinetics of MgH 2 after milling was investigated. We found that the desorption kinetics of MgH 2 were improved more by multiple oxide addition than by single addition. Even for the milled MgH 2 micrometric size powders, the high hydrogen capacity with fast kinetics were achieved for the powders after addition of 0.2 mol% Cr 2 O 3 + 1 mol% Nb 2 O 5 . For this composition, the hydride desorbed about 5 wt.% hydrogen within 20 min and absorbed about 6 wt.% in 5 min at 300 °C. Furthermore, the desorption temperature was decreased by 100 °C, compared to MgH 2 without any oxide addition, and the activation energy for the hydrogen desorption was estimated to be about 185 kJ mol −1 , while that for MgH 2 without oxide was about 206 kJ mol −1 .

The kinetics of hydrogen reaction (absorption and desorption) on the MgH2 have been reported to be improved significantly by addition of transition metal oxides as catalysts. Among the oxides reported previously, Cr2O3 seems to improve hydrogen absorption kinetics and Nb2O5 for desorption kinetics. The catalytic effect of addition of more than one oxide, however, has not been reported yet. We investigated the hydrogen reaction kinetics of ball milled MgH2 powders added with either Cr2O3 or ZnO together with Nb2O5. In absorption reaction, the hydrogen contents reached 6 wt% and 5.3 wt% in 5 min for the powders added with 1 mol% ZnO + 1 mol% Nb2O5 and with 1 mol% Cr2O3 + 1 mol% Nb2O5, respectively. Those powders desorbed hydrogen up to about 4.5 wt% in 20 min. The significant improvement was not expected if one of the oxides was added separately. The combination of two kinds of oxides might play an important role for improvement of reaction kinetics.

Solid oxides fuel cells (SOFCs) is one technology that could contribute toward future sustainable energy. One of the most important components of an SOFC is the electrolyte, which must have high ionic conductivity. Cation substitution of vanadium in Bi4V2O11 yields a family of fast oxide ion conducting solids known collectively as the BIMEVOXes (bismuth metal vanadium oxide), which have the potential to be applied as electrolytes in SOFCs. The purpose of this work is to study the effect of Ni concentration, when used as a dopant, on the ionic conductivity of Bi2NixV1−xO5.5−3x/2 (BINIVOX) oxides (0.1 ≤ x ≤ 0.2) when prepared by a sol gel method. The gels were calcined at 600 °C for 24 h to produce pure BINIVOX. These oxides were found to exhibit the γ-phase structure with tetragonal symmetry in space group I4/mmm. Ionic conductivity of BINIVOX at 300 °C were 6.9 × 10−3 S cm−1, 1.2 × 10−3 S cm−1, and 8.2 × 10−4 S cm−1, for x = 0.1; 0.15; and 0.2; respectively; and at 600 °C were 1.1 × 10−1 S cm−1, 5.3 × 10−...