Electrochemistry Communications最新文献

At present, organic wastewater containing dyes has become one of the main threats to the environment, and wastewater pollution caused by dyes released from fabrics during home washing also accounts for a large proportion. In this study, Ti/IrO₂ electrodes for dye waste degradation were designed and prepared with Reactive Yellow 210 (RY 210), Reactive Blue 19 (RB 19) and Reactive Blue 21 (RB 21) solutions, and a laboratory electrochemical reactor was constructed. Secondly, in the reactor, the effects of current density (20–60 mA cm⁻²), electrolyte concentration (NaCl, 0.01–0.03 M L⁻¹), and initial dye concentration (30–70 mg L⁻¹) on the COD degradation rate and energy consumption of the dye solution were explored, and the parameters were optimized by the Box-Behnken design, and the equipment was realized in the washing machine. The results showed that the effect of degradation parameters on the degradation of the three groups of dyes was: current density > initial dye concentration > electrolyte concentration. Through parameter optimization, the average COD degradation rates of the three groups of dyes, Reactive Yellow 210 (RY 210), Reactive Blue 19 (RB 19) and Reactive Blue 21 (RB 21), reached 50.71%, 41.65%, and 33.12%, respectively, and the degradation energy consumption decreased by the same trend as 29.91%, 26.49%, and 65.91%, respectively.

In this work, a novel strand displacement polymerization strategy is designed with a single hairpin-structured DNA probe acting as both of primer and template. After target miRNA-induced structural transitions, extension and displacement reactions occur at the dimer with recycled target miRNA. The generated double-stranded products further activate CRISPR/Cas12a collateral cleavage of substrate DNA at the electrode surface, which can be reflected by the silver stripping peak variations. By analyzing the reduced peak intensity, the concentration of miRNA can be determined. This method combines the strand displacement amplification and CRISPR/Cas12a’s shearing capability. Thus a highly sensitive electrochemical biosensor is established with the limit of detection as low as 31 aM. It may also inspire new ideas of electrochemical platforms integrating CRISPR/Cas system for biological studies and clinical applications.

Creatinine is a useful metabolite for the evaluation of Chronic Kidney Disease (CKD). Creatinine concentrations in urine outside of the healthy range of 4 to 15 mM may indicate CKD and other kidney conditions. Early detection and monitoring can provide lifesaving intervention, and as such there is a need to develop rapid, cheap and selective electrochemical creatinine sensors. A simple non-enzymatic creatinine sensing platform enabled by the electrocatalytic response of the metabolite to ferricyanide in alkaline conditions is presented. Studies were made on unmodified glassy carbon (GCE) and screen printed carbon electrodes (SPCE), both giving sensitivity of 21 ± 5 µA mM⁻¹ cm⁻² and limit of detection of ca. 60 µM.

Organic conductive polymers are prime candidates for the on demand or controlled release of neurotrophic proteins which can enhance the electrode-neural interface. In this study, bipolar electrochemistry (BPE) is employed to provide a wireless electrical stimulation that avoids the need for the direct physical connection necessary for conventional approaches. Brain-derived neurotrophic factor (BDNF) was incorporated into polypyrrole (PPy) with poly (2-methoxy-5 aniline sulfonic acid) (PMAS) as a dopant during the course of electrochemical synthesis. The synthetic PPy-PMAS-BDNF material acts as the bipolar electrode and is placed within an electric field generated by two driving electrodes. Controlled release of BDNF is demonstrated, which is wireless powered by BPE. This is likely due to the wirelessly activated redox reactions which induce gaps/channels within the structure. Quantification of the BDNF reveals significant differences in the controlled-release properties of the films driven by BPE compared to conventional wired electrochemistry. Human neuroblastoma cells (SH-SY5Y) cultured on the PPy-PMAS-BDNF electrode were subjected to one-week of wireless electrostimulation. Neurite outgrowth was significantly improved when the polymer containing BDNF and the film BPE stimulation. The data suggest that when the BPE is applied, the cells simultaneously respond to the wirelessly released BDNF and the wireless electrical stimulation through the bipolar electroactive polymer electrode. This synergistic effect promotes enhanced neurite outgrowth across the electrodes.

Fusidic acid and betamethasone are two pharmaceutically active compounds found in topical dosage forms. Sometimes, they can unintentionally wind up in surface water via skin washing. Therefore, a stochastic platform based on a type of calix[4]arene and polyaniline modified screen-printed electrode was developed for their on-site analysis. For both analytes, remarkably wide dynamic ranges (1.0 × 10⁻¹⁷–1.0 × 10⁻⁴ for fusidic acid, and 1.0 × 10⁻¹⁸–1.0 × 10⁻³ for betamethasone) and considerably low limits of quantitation (1.0 × 10⁻¹⁷ for fusidic acid, and 1.0 × 10⁻¹⁸ for betamethasone) were attained. Moreover, the proposed platform was successfully applied to real samples such as topical dosage form and surface water, obtaining recovery values higher than 90.0 % with relative standard deviation values below 0.1 %.

Real-time monitoring of oxygen species during the oxygen evolution reaction (OER) on cobalt oxide, one of the major OER electrocatalysts, was achieved through operando observation using wavelength-dispersive X-ray absorption spectroscopy (XAS) at the oxygen K-edge. The XAS spectra were collected every 3 s during electrode potential sweeping for the OER, and oxygen intermediate species related to the rate-determining step of the OER were detected just below the onset potential. Moreover, the cobalt L-edge XAS results demonstrate that the Co₃O₄ species dominates the surface of the electrode at a relatively high potential region, where the OER occurs. The present technique has significant potential for application in the analysis of solid–liquid interfaces, whose fundamental understanding is useful for further improvement of electrocatalysis.

The focus in the development of catalysts doped with transition metals aims to replace platinum group metal catalysts in fuel cells. However, these non-precious metal catalysts exhibit limited performance in acidic environment for the oxygen reduction reaction (ORR) due to issues such as metal agglomeration and the subsequent loss of active sites. Herein, we synthesised catalysts doped with iron and nitrogen on a composite material consisting of carbide-derived carbon (CDC) and graphene (G), employing an additional nitrogen source dicyandiamide (DCDA), denoted as FeN-CDC/G/DCDA. Our physico-chemical analysis unveiled that the inclusion of DCDA was effective in mitigating metal agglomeration during the synthesis process and increasing the presence of Fe-N_x sites in the catalysts. Notably, the FeN-CDC/G/DCDA catalyst exhibited enhanced ORR activity in acid media with half-wave potential (E_1/2) of 0.76 V, surpassing the performance of the FeN-CDC/G catalyst, which had an E_1/2 value of 0.70 V. Furthermore, the rotating ring-disk electrode results indicated a reduced formation of hydrogen peroxide when employing the FeN-CDC/G/DCDA catalyst. The findings from this study represent a significant step towards the development of efficient catalysts for fuel cells, underscoring the pivotal role of additional nitrogen doping and its positive impact on the ORR performance.

Lithium-rich nickel manganese oxide cathode materials are well known to have limited rate capabilities. In this investigation we demonstrate that modifying a common sol-gel synthetic route by adding simple salts to the precursors during firing can create a molten-salt environment for the synthesis of the material that may results in improved materials and performance attributes. After screening multiple salt species, our findings indicate that the use of NaCl can provide a cost-effective and facile method for increasing the rate capability of these materials.

Composites of reduced graphene oxide coated with amorphous lead (Pb/rGO) were prepared by electrostatic adsorption and hydrothermal methods, and used as positive additives for lead–carbon batteries to enhance discharge specific capacity and cycle life under high-rate partial-state-of-charge (HRPSoC) of batteries. Amorphous Pb inhibits the oxygen evolution reaction (OER) that occurs on the surface of reduced graphene oxide (rGO) and increases the specific capacitance of the positive active material (PAM). In addition, the presence of amorphous Pb enhances the affinity of rGO to PAM, which avoids the separation of additive and PAM during the cycling process. Pb/rGO additives can act as pore forming agents and significantly increase the specific surface area of PAM, which enables the electrolyte to fully react with PAM to inhibit the overgrowth of PbSO₄ crystals. Thus, Pb/rGO additives help to improve the electrochemical performance of batteries. To be specific, when the Pb/rGO additive content is 0.7 wt%, battery showed the best discharge specific capacity (102 mAh/g) and cycle life (18,104 cycles), which is 117% and 104% higher than that of blank battery, respectively. And the rate capability is also improved compared to its counterpart. In short, the Pb/rGO composite material has potential application value in lead–carbon batteries.

This work presents a novel approach for fabricating current collector-free three-dimensional (3D) anodes for Lithium-ion batteries (LIBs) based on MXene, a 2D material with excellent conductivity and lithium-ion intercalation properties. The 3D MXene-based anodes were fabricated through a simple and scalable printing process, eliminating the need for traditional current collectors such as copper foil. The performance of the 3D anodes was characterized in terms of electrochemical properties, including capacity assessment, cycling stability, and rate capability. The results showed that the printed anodes exhibited superior performance, highlighting the potential of this approach for the development of high-performance LIBs. The findings presented in this work have significant implications for the design and manufacturing of next-generation energy storage devices.