scholarly journals Synthesis of Ag-La0.8Sr0.2MnO3 (LSM-Ag) Composite Powder and Its Application in Magnesium Air Battery

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 633
Author(s):  
Xiaohan Wu ◽  
Hui Liu ◽  
Jiaxi Zhang ◽  
Juemin Song ◽  
Jiefeng Huang ◽  
...  

La0.8Sr0.2MnO3 (LSM) catalyst is prepared via a sol-gel method and modified via a typical silver mirror reaction. Silver ammonia solution is reduced in a polyvinylpyrrolidone (PVP)-containing solution to obtain silver nanoparticles and sodium dodecyl sulfate (SDS) is added as a surfactant. The microstructure and morphology of the LSM-Ag composite powder are characterized. According to the results, the Ag particles precipitate on the LSM surface in elemental form and the grain size is about one hundred nanometers. The analysis of electrocatalytic performance of LSM-Ag cathodes with different amounts of silver loading reveals that the number of electrons transferred during the oxygen reduction reaction (ORR) of the cathode with an Ag content of 14% by weight reached 3.9, which is very close to that of commercial Pt/C catalysts. Similarly, the maximum power density of the air battery made of LSM-14%Ag is 73 mW/cm2, which exceeds that of 63 mW/cm2, found for the LSM battery. Finally, increasing the amount of silver loading allows one to improve the electrochemical performance of LSM catalysts. The best effect is achieved when the Ag loading exceeds 14%.

2016 ◽  
Vol 40 (2) ◽  
pp. 462-468 ◽  
Author(s):  
Qi Wang ◽  
Chao Du ◽  
Lingxin Kong ◽  
Haifeng Hu

A novel fibre surface plasmon resonance (SPR) sensor fabricated by a silver mirror reaction is first proposed and demonstrated in this paper. The experimental results showed that the silver film characteristics of the fibre SPR sensing probe are affected by the concentration of silver ammonia solution, and the relations between the concentration of silver ammonia solution and properties of the sensors have been obtained, which is in accordance with the optimal parameters of fibre and silver film through a theoretical simulation. Firstly, a theoretical model of a silver film-based fibre SPR sensing mechanism has been built up. Then the numerical simulations towards the influence of sensing structure, thickness and sensing length of metal films on the sensing system sensitivity have been performed. Finally, the optimal structure parameters of the sensor are obtained. The results show that this fibre SPR sensing system provides a promising platform for sodium chloride solution concentration measurement with a concentration sensitivity of 710.4 nm/%.


Author(s):  
Aling Chen ◽  
Qingfeng Yi ◽  
Kuang Sheng ◽  
Yuebing Wang ◽  
Jiangchuan Chen ◽  
...  

Exploring efficient metal-free electrocatalyst for oxygen reduction reaction (ORR) plays a significant role in a variety of storage technologies and renewable energy conversion. In this work, we firstly compounded a...


Author(s):  
I-Hsuan Chen ◽  
Jung-Hsien Chang ◽  
Ren-Jie Xie ◽  
Chia-Hui Tseng ◽  
Sheng-Rong Hsieh ◽  
...  

Abstract In this study, the easy-to-operate silver mirror reaction (SMR) was used for metallizing chromatography paper. The SMR-metallized paper was characterized by water contact angle measurements, a surface profiler, X-ray photoelectron spectroscopy, UV-vis spectroscopy, X-ray diffraction, and electrical resistance measurement. The characterization results show that Ag was successfully synthesized on cellulose fibers and was electrically conductive after cyclic bending. Moreover, this SMR-metallized paper was used as electrodes for fabricating a supercapacitor. This SMR-metallized paper could be used for realizing cost-effective flexible electronics applied in on-site biochemical sensing in resource-limited settings.


2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Lili Lei ◽  
Chuan Sun ◽  
Bo Zhang ◽  
Wenye Gu

A series of Pt-Ce-Ba/γ-Al2O3and Mn-Ce/γ-Al2O3catalysts were synthesized by a sol-gel method and the samples were characterized by XRD, SEM, and EDS. The effect of Mn-Ce/γ-Al2O3on the storage and reduction of NOxover Pt-Ce-Ba/γ-Al2O3catalysts was studied in a fix-bed reactor with simulation gases NO, O2, and N2. The results indicated that NO oxidation to NO2was reduced with the increase of inlet NO concentration, which was up to 83% when the concentration of NO was 500 ppm but reduced to 76% with the concentration of NO increasing to 1000 ppm. Comparing with the Pt-Ce-Ba/γ-Al2O3catalysts, the rate of NOxstorage and reduction was remarkably increased over Pt-Ce-Ba/γ-Al2O3combined with Mn-Ce/γ-Al2O3catalysts. However, the reductant used for NOxreduction reaction over Pt-Ce-Ba/γ-Al2O3catalysts was consumed under the treatment of Mn-Ce/γ-Al2O3catalyst, which caused the NOxconversion to obviously drop, but the rate of NOxabsorption declined slightly.


Author(s):  
Kaykobad Md. Rezaul Karim ◽  
Huei Ruey Ong ◽  
Hamidah Abdullah ◽  
Abu Yousuf ◽  
Chin Kui Cheng ◽  
...  

In this work, p-type CuFe2O4 was synthesized by sol gel method. The prepared CuFe2O4 was used as photocathode catalyst for photoelectrochemical (PEC) CO2 reduction. The XRD, UV-Visible Spectroscopy (UV-Vis), and Mott-Schottky (MS) experiments were done to characterize the catalyst. Linear sweep voltammetry (LSV) was employed to evaluate the visible light (λ>400 nm) effect of this catalyst for CO2 reduction.  The band gap energy of the catalyst was calculated from the UV-Vis and was found 1.30 eV. Flat band potential of the prepared CuFe2O4 was also calculated and found 0.27 V versus Ag/AgCl. Under light irradiation in the CO2-saturated NaHCO3 solution, a remarkable current development associated with CO2 reduction was found during LSV for the prepared electrode from onset potential -0.89 V with a peak current emerged at -1.01 V (vs Ag/AgCl) representing the occurrence of CO2 reduction reaction. In addition, the mechanism of PEC was proposed for the photocathode where the necessity of a bias potential in the range of 0.27 to ~ -1.0 V vs Ag/AgCl was identified which could effectively inhibit the electron-hole (e-/h+) recombination process leading to an enhancement of CO2 reduction reactions. Copyright © 2018 BCREC Group. All rights reservedReceived: 4th July 2017; Revised: 5th November 2017; Accepted: 15th November 2017; Available online: 11st June 2018; Published regularly: 1st August 2018How to Cite: Karim, K.M.R., Ong, H.R., Abdullah, H., Yousuf, A., Cheng, C.K., Khan, M.K.R. (2018). Electrochemical Study of Copper Ferrite as a Catalyst for CO2 Photoelectrochemical Reduction. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (2): 236-244 (doi:10.9767/bcrec.13.2.1317.236-244) 


2008 ◽  
Vol 6 (2) ◽  
pp. 222-228 ◽  
Author(s):  
Sheikha Al-Ghannam ◽  
Abeer Al-Olyan

AbstractA simple and highly sensitive spectrofluorometric method was developed for the determination of some 1,4-dihydropyridine compounds namely, nicardipine, nifedipine and isradipine in pharmaceutical preparations and biological fluids. The method is based on the reduction of nicardipine, nifedipine and isradipine with Zn/HCl and measuring the fluorescence intensity obtained (λem/λex) at 460/364, 450/393 and 446/360 nm, respectively. The factors affecting the development of the fluorophore and its stability were studied and optimized. The effect of some surfactants such as β-cyclodextrin (βCD), carboxymethylcelullose (CMC), sodium dodecyl sulphate (SDS) and triton X-100, on the fluorescence intensity was studied. The fluorescence intensity-concentration plots of nicardipine, nifedipine and isradipine were rectilinear over the ranges 0.4–6.0, 0.2–4.0 and 0.1–9.0 μg ml−1 with detection limits of 0.0028, 0.017 and 0.016 μg ml−1, respectively. The proposed method was successfully applied to commercial tablets containing the compounds; the percentage recovery agreed well with those obtained using the official methods. The method was further extended to the in vitro determination of the compounds in spiked human plasma and urine samples. A proposal of the reduction reaction pathway was postulated.


Author(s):  
Xin Yu Gao ◽  
Xingwei Sun ◽  
Jia Hui Guo ◽  
Ya Nan Teng ◽  
Lei Liu ◽  
...  

The exploration of bifunctional oxygen electrode towards oxygen evolution reaction (OER) activity and oxygen reduction reaction (ORR) is the bottlenecks for the development of rechargeable zinc-air battery as a clean...


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