Sustainable Electrochemical NO Capture and Storage System Based on the Reversible Fe2+/Fe3+-EDTA Redox Reaction

The removal of nitric oxide (NO), which is an aggregation agent for fine dust that causes air pollution, from exhaust gas has been considered an important treatment in the context of environmental conservation. Herein, we propose a sustainable electrochemical NO removal system based on the reversible Fe2+/Fe3+-ethylenediamine tetraacetic acid (EDTA) redox reaction, which enables continuous NO capture and storage at ambient temperature without the addition of any sacrificial agents. We have designed a flow-type reaction system in which the NO absorption and emission can be separately conducted in the individual reservoirs of the catholyte and anolyte with the continuous regeneration of Fe2+-EDTA by the electrochemical reduction in Fe3+-EDTA. A continuous flow reaction using a silver cathode and glassy carbon anode showed that the concentrations of Fe2+ and Fe3+-EDTA in the electrolyte were successfully maintained at a 1:1 ratio, which demonstrates that the proposed system can be applied for continuous NO capture and storage.

Redox Flow Capacitive Deionization in a Mixed Electrode Solvent of Water and Ethanol

In the redox flow electrode capacitive deionization (FCDI), the solubility of redox electrolyte and flowability of carbon slurry have great influence on the salt removal rate and energy consumption. In this work, a mixed solvent electrolyte is proposed in FCDI, which consists of iodide/triiodide redox couples and carbon slurry in the mixed solvent of water and ethanol (1:1). At the current density of 5 mA cm-2, the salt removal rate can reach up to 2.72 μg cm-2 s-1 in a mixed solvent, which is much higher than 1.74 μg cm-2 s-1 in aqueous solution and 2.37 μg cm-2 s-1 in the ethanol solution. This may be owing to the fast transport of ions during redox reaction in organic solvent and the excellent flowability of carbon slurry in the aqueous condition, which can provide more reaction sites for iodide/triiodide redox reaction and faster electron transportation. This unique FCDI with organic and aqueous mixed solvent electrolyte will provide a new perspective for the development of redox flow electrochemical desalination.

Hierarchical α-MnO2 Nanowires as an Efficient Anode Material for Rechargeable Lithium-Ion Batteries

In this work, a bulk quantity of α-MnO2 hierarchical nanowires synthesized by a facile redox reaction between potassium permanganate (KMnO4) and glycine under ambient conditions. The physicochemical characterization results reveal...

Stepwise synthesis of a Zr–C–Si main chain polymer precursor for ZrC/SiC/C composite ceramics

Low valence state Cp2Zr(ii) was firstly obtained by a redox reaction of Cp2ZrCl2 with reductive Mg, which subsequently copolymerized with (CH3)2Si(CH2Cl)2 to form a Zr–C–Si main chain polymeric precursor of polyzirconosilane (PZCS).

Monosaccharide-Mediated Rational Synthesis of a Universal Plasmonic Platform With Broad Spectral Fluorescence Enhancement For High-Sensitivity Cancer Biomarker Analysis

BackgroundEffective and accurate screening of oncological biomarkers in peripheral blood circulation plays an increasingly vital role in diagnosis and prognosis. High-sensitivity assays can effectively aid clinical decision-making and intervene in cancer in a localized status before they metastasize and become unmanageable. Meanwhile, it is equally pivotal to prevent overdiagnosis of non-life-threatening cancer by eliminating unnecessary treatment and repeated blood draws. Unfortunately, current clinical screening methodologies can hardly simultaneously attain sufficient sensitivity and specificity, especially under resource-restrained circumstances. To circumvent such limitations, particularly for cancer biomarkers from early-onset and recurrence, we aim to develop a universal plasmonic platform for clinical applications, which macroscopically amplifies multiplexed fluorescence signals in a broad spectral window readily adapts to current assay setups without sophisticated accessories or expertise at low cost. MethodsThe plasmonic substrate was chemically synthesized in situ at the solid-liquid interface by rationally screening a panel of reducing monosaccharides and tuning the redox reactions at various catalyst densities and precursor concentrations. The redox properties were studied by Benedict’s assay and electrochemistry. We systemically characterized the morphologies and optical properties of the engineered plasmonic Ag structures by scanning electron microscopy (SEM) and spectroscopy. The structure-fluorescence enhancement correlation was explicitly explained by the finite-difference time-domain (FDTD) simulation and a computational model for gap distribution. Next, we established an enhanced fluoroimmunoassay (eFIA) using a model biomarker for prostate cancer (PCa) and validated it in healthy and PCa cohorts. Prognosis was explored in patients subject to surgical and hormonal interventions following recommended PCa guidelines. ResultsThe monosaccharide-mediated redox reaction yielded a broad category of Ag structures, including sparsely dispersed nanoparticles of various sizes, semi-continuous nanoislands, and crackless continuous films. Optimal broad-spectral fluorescence enhancement from green to far-red was observed for the inhomogeneous, irregularly-shaped semi-continuous Ag nanoisland substrate (AgNIS), synthesized from a well-balanced redox reaction at a stable rate mediated by mannose. In addition, different local electric field intensity distributions in response to various incident excitations were observed at the nanoscale, elucidating the need for irregular and inhomogeneous structures. AgNIS enabled a maximized 54.7-fold macroscopically amplified fluorescence and long-lasting photostability. Point-of-care availability was fulfilled using a customized smartphone prototype with well-paired optics. The eFIA effectively detected the PCa marker in cell lines, xenograft tumors, and patient sera. The plasmonic platform rendered a diagnostic sensitivity of 86.0% and a specificity of 94.7% and capably staged high-grade PCa that the clinical gold standard test failed to stratify. Patient prognosis of surgical and hormonal interventions was non-invasively monitored following efficient medical interventions. The assay time was significantly curtailed on the plasmonic platform upon microwave irradiation. ConclusionsBy investigating the effects of monosaccharides on the seed-mediated chemical synthesis of plasmonic Ag structures, we deduced that potent multiplexed fluorescence enhancement originated from both an adequate reducing power and a steady reduction rate. Furthermore, the inhomogeneous structure with adequate medium gap distances afforded optimal multiwavelength fluorescence enhancement, thus empowering an effective eFIA for PCa. The clinically validated diagnostic and prognostic features, along with the low sample volume, point-of-care feasibility with a smartphone, and microwave-shortened assay time, warrant its potential clinical translation for widespread cancer biomarker analysis.

PENINGKATAN HASIL BELAJAR MATERI REAKSI REDOKS MELALUI MODEL PEMBELAJARAN PROBLEM SOLVING PADA SISWA KELAS X MIPA 3 SMAN I KEMBANGBAHU LAMONGAN

This study aims to determine the application of problem solving learning models in improving chemistry learning outcomes in redox reaction material for students of Class X MIPA 3 SMA Negeri 1 Kembangbahu Lamongan, East Java province. The research was carried out in the even semester of the 2019/2020 school year. This type of research is classroom action research (CAR) which consists of four stages, namely planning, implementing actions, observing and reflecting. This study uses 2 cycles of action. Data collection techniques used: observation, tests, field notes and documentation. Problem solving learning model is applied in a way, students are faced with a problem, then asked to solve it in groups. Students' ability to understand lessons through problem solving models can be seen from the test results. The test was administered in two stages, namely the first cycle test and the second cycle test. Based on the results of student tests, classical completeness was 75% in the first cycle and 85% in the second cycle. Based on the results of the study, it can be concluded that using a problem solving learning model can improve chemistry learning outcomes for Class X MIPA 3 students at SMA Negeri 1 Kembangbahu Lamongan in the even semester of the 2019/2020 school year on redox reaction material. ABSTRAKPenelitian ini bertujuan untuk mengetahui penerapan model pembelajaran problem solving dalam meningkatkan hasil belajar kimia pada materi reaksi redoks siswa Kelas X MIPA 3 SMA Negeri 1 Kembangbahu Lamongan provinsi Jawa Timur. Penelitian dilaksanakan pada semester genap tahun pelajaran 2019/2020. Jenis penelitian ini adalah penelitian tindakan kelas (PTK) yang terdiri terdiri atas empat tahap, yaitu perencanaan, pelaksanaan tindakan, pengamatan dan refleksi. Penelitian ini menggunakan 2 siklus tindakan. Teknik pengumpulan data menggunakan: observasi, tes, catatan lapangan dan dokumentasi. Model pembelajaran Problem solving diterapkan dengan cara, siswa dihadapkan pada suatu masalah, kemudian diminta untuk memecahkannya secara berkelompk. Kemampuan siswa dalam memahami pelajaran melalui model problem solving dapat dilihat dari hasil tes. Pemberian tes dilakukan dua tahap yaitu tes siklus I, dan tes siklus II. Berdasarkan hasil tes siswa diperoleh ketuntasan secara klasikal sebesar 75% pada siklus I dan 85% pada siklus II. Berdasarkan hasil penelitian, maka dapat disimpulkan bahwa dengan menggunakan model pembelajaran problem solving dapat meningkatkan hasil belajar kimia siswa Kelas X MIPA 3 SMA Negeri 1 Kembangbahu Lamongan semester genap tahun pelajaran 2019/2020 pada materi reaksi redoks.