Er, Omer FarukKivrak, HilalOzok, OmruyeCelik, Sebahattin...
7页
查看更多>>摘要：COVID-19 crisis affects ovarium cancer patients seriously. Thus, it is vital to diagnose ovarium cancer, one of the most common types of cancer diagnosed and the causes of death of women around the world, at early stages. Herein, 5-(2-phenylbenzo[b]thiophen-3-yl) thiophene-2-carbaldehyde (PTTC)-based sensor is designed to detect CA-125 more precisely and rapidly via electrochemical methods. PTTC, novel benzothiophene derivative, is synthesized by electrophilic cyclization reactions and Pd-catalyst coupling reactions. Then, PTTC is dispersed homogeneously in Nafion solution, and an ink is obtained. This ink is transferred onto the glassy carbon electrode and CA-125 is incubated on this electrode. Cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy measurements are employed to determine sensitivity and reliability of CA-125 on PTTC based GCE electrode. The effect of CA 125 concentration, incubation time, scan rate studies are performed by CV to determine the optimum conditions. Optimum conditions are found as 3 mu L PTTC loading, 5000 ng/mL CA125 antigen concentration and 30 min incubation time. Linear range of the PTTC based GCE electrode prepared at optimum conditions are obtained by DPV as 1-100 ng/ml.Limit of detection and limit of quantification values were obtained as 0.0096 ng/mL and 0.0288 ng/mL, respectively. Interference and artificial serum results reveal that this electrode is a promising electrode for CA125 antigen determination for the ovarium cancer. PTTC is a novel and unique material for the detection of ovarium cancer antigen CA-125 and promising for CA-125 antigen detection.
查看更多>>摘要：It is still challenging to design and synthesize highly efficient and noble-metal-free electrocatalysts for hydrogen/oxygen evolution reaction (HER/OER). Herein, we developed an in-situ phosphating Co@nitrogen-doping graphene to obtain N and P co-doped carbon-coated cobalt phosphide (CoP@N,P-C) that could be used for overall water splitting. The unique 3D porous structure of CoP@N,P-C is characterized by a large number of active catalytic sites. High wettability of catalyst in electrolyte solution facilitates the transfer of ions. The synergism between the CoP cores and N, P-C shells improves the total hydrolysis performance of the electrocatalyst during the HER and OER. M the current densities of 10 mA/cm(2) (1 M of KOH), the HER overpotential recorded for the CoP@N,P-C is 113 mV, and the OER overpotential is 320 mV. The cell voltage of the CoP@N, P-C as bifunctional electrode for overall water splitting is 1.67 V (at 10 mA/cm(2)), which is close to that of the full noble-metal electrode (RuO2 parallel to PVC, 1.58 V). The CoP@N, P-C bifunctional catalyst can be potentially used to replace noble-metal electrodes to realize water splitting.
查看更多>>摘要：In this work, a simple strategy of carbon paste electrode (CPE) modification with previously synthesized iridium(III) complex i.e. [Ir(3m-ppy)(2)(dppm)Cl] (3m-ppy = 3-methyl-2-phenylpyridine, dppm = bis (diphenylphosphino)methane) was elaborated together with first application of [Ir(3m-ppy)(2)(dppm)Cl] as working electrode component for H2O2 amperometric determination. The electrode with iridium(III) complex (Ir/CPE) was prepared in one step using optimized drop coating procedure. The characterization of Ir/CPE by scanning electron microscopy in combination with energy dispersive spectrometry confirmed the presence of densely populated Ir(III) complex based microspherical particles self-assembled on the electrode surface. Comparative cyclic voltammetric responses of the Ir/CPE and pristine CPE in phosphate (pH 7.50) and acetate (pH 4.50) buffer solution proved that in both supporting electrolytes in the case of the modified electrode one irreversible oxidation peak is present with maximum close to 1.2 V vs. SCE. Comparative measurements were performed with both electrodes in the presence of H2O2 target analyze, and it was found that after appropriate electrochemical activation at 1.20 V, during 60 min, the Ir complex containing electrode is a promising sensor for analytical purposes offering the possibility for the analysis of H2O2 at working potentials in anodic range from 0.30 to 0.60 V and in cathodic range from -0.05 to -0.30 V in phosphate buffer pH 7.50 (0.1 M) as supporting electrolyte. The optimized amperometric protocol which included stirred solution, electrochemical activation of the electrode and working potential as 0.60 V vs. SCE showed acceptable linearity of the calibration curve for the investigated H2O2 concentration range from 51.5 to 508.2 mu M, and with evaluated LOQ as 8.8 mu M. Additionally, this electrode exhibited good stability and reproducibility with relative standard deviation lower than 3%. The optimized and simple amperometric method was successfully applied for determination of H2O2 content in commercially available color cream developers and obtained results were in a good agreement with declared values by the producers indicating the reliability of prepared H2O2 sensor.
Su, YiwenYang, XianzhongZhang, QihuiSun, Jingyu...
13页
查看更多>>摘要：Aqueous zinc-ion battery has readily showed its cutting edges as one of the most promising energy storage systems due to high theoretical capacity and good environmental benignancy. Issues in particular at the anode side encompassing rampant dendrite growth, severe corrosion and side reactions otherwise impede the pragmatic applications. Carbon nanomaterials have been widely employed to protect Zn anode benefiting from their collective merits. Nevertheless, there has been a lack of comprehensive reviews thus far on covering the strategic solutions of Zn anode stabilization with the aid of nano-carbons. This article summarizes the state-of-the-art knowledge in designing concepts, mechanism investigations and device performances of Zn anode protection strategies based on carbon nanomaterials. Future perspectives and key challenges in this emerging field are included at the end.
查看更多>>摘要：As a continued research interest for energy conversion and chemical analysis purpose, illustrating the reaction kinetics of homogeneous electrocatalytic reaction is crucial in the understanding of redox mediation process. In this paper, the reaction kinetics of the homogeneous electrocatalytic reaction between N,N,N',N'-tetramethylpara-phenylene-diamine (TMPD) and ascorbic acid (AA) is extracted via a 1D homogeneous electrocatalytic reaction model based on finite element methods. The experimental voltammograms reveal the waveform transition in terms of kinetic parameter and excess factor and an oxidative pre peak is observed at the scan rate of 1 mV s-1. Based on the results above, the same 1D homogeneous electrocatalytic reaction model is employed for the extraction of reaction rate constant between TMPD center dot+ and AA. A transition region of the voltammetric waveform is illustrated under different scan rates and the methodology for the kinetics extraction under specific scan rate is defined. The obtained ke value is (2.61 +/- 0.11 (mol m-3)-1 s-1) and this value is further verified by experimental voltammograms under various scan rates and substrate concentrations. In conclusion, the proposed kinetics extraction methodology reflects the electrocatalytic reaction between TMPD and AA. Also, the employment of waveform transition region facilitates the understanding of the redox mediation process.
查看更多>>摘要：The two-dimensional layered tin disulfide (SnS2) has aroused extensive attention in both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) since its satisfactory theoretical capacity. Herein, the anode material comprised of SnS2 nanosheets grown in-situ on S-doped reduced graphene oxide sheets (SnS2/S-rGO) was successfully prepared via a one-step hydrothermal method. SnS2 nanosheets are covalently linked to rGO by a CAS bond, this special structure endows outstanding electrochemical performance for SnS2/S-rGO electrode. At 0.1 A g-1, it delivers a specific capacity of 1641.9 mAh g-1 and 610.5 mAh g-1 for lithium and sodium storage, respectively. Furthermore, the electrode can also maintain 1776.4 mAh g-1 even after 200 cycles exhibiting a splendid long cycle performance at 1 A g-1 for LIBs. Obviously, the structural design of the SnS2/S-rGO composite show advantages in lithium/sodium storage performance.
查看更多>>摘要：The detection of hydrogen peroxide (H2O2) has considerable significance in industrial application and pathological monitoring. Inspired by the attributes of functional mesoporous carbons, a non-enzymatic sensor was constructed based on AgNPs doping carbon nanoflower composites (AgNPs/CNF). The characterization results showed that AgNPs/CNF with nanoflower structure greatly enhanced electron transfer rate and displayed outstanding catalytic performance for H2O2. Remarkably, the prepared sensor presented super low detection limit (5.83 x 10-11 M) and the wider detection range (1.75 x 10-10 - 5.41 x 10-3 M). In addition, the content of H2O2 in the actual disinfectant and human serum samples were further detected, and the recover ratios were 96.00 % - 104.0 % and 96.00-105.2 %, respectively, indicating the prepared sensor can detect H2O2 effectively.
查看更多>>摘要：This study introduces laser irradiation into the electrodeposition of Cu-Al2O3 composite coatings. The cavitation bubble generated by laser breakdown in the solution caused strong shockwaves and micro-area agitation that reduced the agglomeration of Al2O3 particles. The shockwave signal was then detected using a hydrophone. Laser irradiation also increased the electrodeposition current due to agitation and temperature rising. The samples prepared by laser assisted electrodeposition with different laser energies were studied. The surface and cross-section morphology were observed using scanning electron microscopy and the content of Al2O3 nanoparticles was measured using X-ray fluorescence spectroscopy. Moreover, the microhardness and corrosion resistance were also studied. The results showed a composite coating with a smoother surface and fewer defects compared to samples prepared by traditional electrodeposition. The content of Al2O3 nanoparticles was increased owning to laser irradiation. Finally, the increase in laser energy, enhanced the microhardness and corrosion resistance of the composite coating.
查看更多>>摘要：The electrochemical behavior of some of the most relevant endocrine-disrupting phenols using unmodified car-bon screen-printed electrodes (SPEs) is described for the first time. Experiments were made to assess the electro-chemical behavior of phenol (PHOH), pentachlorophenol (PCP), 4-tert octylphenol (OP) and bisphenol A (BPA) and their determination in the most favorable conditions, using voltammetric methods such as cyclic voltamme-try (CV), linear sweep voltammetry (LSV) and square wave voltammetry (SWV) in Britton Robinson (BR) buffer. Further, the usefulness of the electrochemical approach was validated with real samples from a local river and was compared to commercial phenols test kit, which is commonly used for on-site screening in industrial streams and wastewaters. Finally, the approach was compared with a lab-bench standard method using real samples, i.e., high-performance liquid chromatography with a photodiode array detector (HPLC-DAD).
查看更多>>摘要：For the development of sustainable crop-based energy materials, phosphorus and nitrogen binary doped porous C/SiOx composites (PN@C/SiOx) have been fabricated using rice husks as the Si and C source and (NH4)(3)PO4 as the P and N source through a facile and environmentally friendly approach. The obtained PN@C/SiOx composites possess a hierarchical porous structure and SiOx particles are uniformly distributed in the P,N-doped C skeleton. The porous P,N-doped C skeleton not only facilitates the ion transport and penetration of electrolyte, but also alleviates the volume expansion and agglomeration of SiOx particles. The P and N co-doping can generate additional defective sites on the C matrix surface, which enhances electronic conductivity and energy storage performance. Due to the above advantages, the optimized PN@C/SiOx composite as anode of lithium-ion batteries (LIBs) presents an excellent reversible specific capacity of 1078 mAh/g at 0.1 A/g and improved initial coulombic efficiency (CE) of 73.6%. Even at 1.0 A/g, a steady specific capacity of 622 mAh/g still could be achieved after 1000 cycles. It is believed that this strategy has great potential in large-scale production of new energy materials for future practical applications.
NSTL
Elsevier