A Dual-Function Cobalt Metal-Organic Framework for High Proton Conduction and Selective Luminescence Sensing of Histidine

Proton exchange membrane (PEM) is a key component of proton exchange membrane fuel cells (PEMFCs). In recent years, metal organic framework (MOF) and its composite membranes have become the research hotspots. [Co(L-Glu)(H2O)•H2O]n (Co-MOF, L-Glu = L-glutamate) was synthesized by hydrothermal method. Co2+ ions are coordinated with L-Glu ligands and water molecules to form one-dimensional chains extending along the a-axis, which are further bridged by L-Glu ligands to form a three-dimensional network structure. AC impedance analysis shows that the proton conductivity of Co-MOF reaches 3.14×10-4 S•cm-1 under 98% relative humidity (RH) and 338 K. To improve proton conductivity, different contents of Co-MOF were added in chitosan (CS) to form composite membranes Co-MOF@CS-X (mass fraction X= 5%, 10%, 15% wt). The results show the proton conductivity of the Co-MOF@CS-10 composite membrane is 1.73×10-3 S•cm-1 at 358 K and 98% RH, which is more than 5 times that of Co-MOF. As far as we known, this is the first composite made of amino acid MOFs and CS as proton exchange membrane. Furthermore, Co-MOF has an obvious quenching effect on L-histidine in aqueous solution, which can detect the content of L-histidine in water with high sensitivity, and the detection limit is 1×10-7 M.

Optimization of Benzoguanamine doped PVDF/KI/I2 Solid Polymer Electrolytes for Dye-Sensitized Solar Cell Applications

Benzoguanamine doped 0%, 10%, 20%, 30%, 40% and 50% PVDF/KI/I2 polymer electrolytes were prepared by solution casting technique. The crystallinity, surface morphology, ionic conductivity and photovoltaic performance of polymer electrolytes were analyzed. The PXRD studies have confirmed the decreased and increased crystallinity of benzoguanamine doped polymer electrolytes. The surface morphology of polymer electrolytes is discussed using SEM analysis. From the AC-impedance analysis, ionic conductivity of benzoguanamine doped 0%, 10%, 20%, 30%, 40% and 50% PVDF/KI/I2 polymer electrolytes were calculated as 5.57 × 10− 6 Scm− 1, 1.05 × 10− 5 Scm− 1, 5.95 × 10− 5 Scm− 1, 3.09 × 10− 5 Scm− 1, 1.56 × 10− 5 Scm− 1 and 1.48 × 10− 5 Scm− 1, respectively. The photovoltaic performance of benzoguanamine doped 0%, 10%, 20%, 30%, 40% and 50% PVDF/KI/I2 polymer electrolytes based DSSCs have achieved 1.5%, 1.9%, 2.8%, 2.5%, 2.3% and 2.1% power conversion efficiency, respectively.

Biopolymer Electrolyte Based on Gellan Gum With Magnesium Chloride for Magnesium Battery

Eco-Friendly, non-toxic and biodegradable natural biopolymer electrolyte, Gellan Gum with Magnesium Chloride has been prepared by solution casting technique. The prepared biopolymer electrolyte has been characterized by XRD, FTIR, DSC and AC impedance analysis techniques. XRD study is used to analyze amorphous nature/crystalline nature of the polymer electrolyte. Complex formation between Gellan Gum and magnesium chloride salt has been studied by FTIR technique. The glass transition temperature (Tg) of the polymer electrolytes are obtained by DSC measurement. The highest ionic conductivity 2.91×10− 2 Scm− 1 has been obtained for electrolyte of 1.0 g Gellan Gum with 0.5 M.wt% MgCl2 from AC impedance analysis at room temperature. Transference number 0.97 has been obtained by Wagner’s polarization method for high conducting sample. The Mg2+ cationic transport number 0.35 has been found by Evan’s method for high conducting sample. Magnesium ion conducting battery has been constructed using the high conducting polymer electrolyte. Its open circuit voltage 2.39 V and the battery discharge characteristics are studied.

A Bulk-Heterostructure Nanocomposite Electrolyte of Ce0.8Sm0.2O2-δ–SrTiO3 for Low-Temperature Solid Oxide Fuel Cells

Since colossal ionic conductivity was detected in the planar heterostructures consisting of fluorite and perovskite, heterostructures have drawn great research interest as potential electrolytes for solid oxide fuel cells (SOFCs). However, so far, the practical uses of such promising material have failed to materialize in SOFCs due to the short circuit risk caused by SrTiO3. In this study, a series of fluorite/perovskite heterostructures made of Sm-doped CeO2 and SrTiO3 (SDC–STO) are developed in a new bulk-heterostructure form and evaluated as electrolytes. The prepared cells exhibit a peak power density of 892 mW cm−2 along with open circuit voltage of 1.1 V at 550 °C for the optimal composition of 4SDC–6STO. Further electrical studies reveal a high ionic conductivity of 0.05–0.14 S cm−1 at 450–550 °C, which shows remarkable enhancement compared to that of simplex SDC. Via AC impedance analysis, it has been shown that the small grain-boundary and electrode polarization resistances play the major roles in resulting in the superior performance. Furthermore, a Schottky junction effect is proposed by considering the work functions and electronic affinities to interpret the avoidance of short circuit in the SDC–STO cell. Our findings thus indicate a new insight to design electrolytes for low-temperature SOFCs.

Reverse Synchronous Transmission of Electrical Signals Based on Parallel Injection and Series Pickup

To eliminate the interference with the transmission of electrical signals, this paper puts forward a reverse synchronous transmission (RST) control method based on parallel injection and series pickup. Firstly, the synchronous transmission mechanism of electrical signals was analyzed, followed by the design of the framework and workflow of signal transmission. Next, an RST channel model was established for electrical signals, and the transmission parameters were configured based on the transmission properties of these signals. Through alternative current (AC) impedance analysis, the Laplace transform was performed on the transmission loop to increase the voltage of the transmission channel, and to elevate the signal-to-noise ratio (SNR) of the voltage across the resistor. Finally, the voltage comparator was adopted to obtain the digital information of the baseband signal, and the power signal was transmitted to the RST channel, completing the RST control of electrical signals. The experimental results show that the transmission speed of the system was 0.7488, and the reverse transmission of electrical signals was only delayed by 5ms, when the intensity of electromagnetic radiation was 2.0μT. Through parallel injection and series pickup, the proposed system can effectively realize the RST of electrical signals, without changing the topology of the transmission system.

Preparation and Characterization of Ammonium Ceric Nitrate Doped PVDF Polymer Electrolytes

Poly [vinylidene fluoride] (PVdF): Ammonium ceric nitrate ((NH4)2Ce(NO3)6) based Proton conducting solid polymer electrolytes (SPEs) are prepared by solution casting technique. Polymer electrolytes are characterized by several techniques. The Structural property of the electrolytes are confirmed by XRD. The functional groups present in polymer electrolytes are confirmed by FTIR. The conductivity of the polymer electrolytes are calculated by using AC impedance analysis. The Maximum ionic conductivity is obtained for 2wt% of ammonium ceric nitrate doped polymer electrolyte.