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In this study, carbon nanotube (CNT) supported M(Bi, Cu, Fe, Nb) catalysts were prepared by the sodium borohydride (SBH) reduction method for hydrazine electro-oxidation. The structural and morphological surface analyses of the 3% Cu/CNT catalyst were characterized by X-Ray diffraction (XRD) and scanning electron microscopy-energy dispersive X-Ray (SEM-EDX) and mapping analyses. The catalytic activities of the catalysts were investigated by cyclic voltammetry (CV) analysis. The 3% Cu/CNT catalyst exhibited the best catalytic activity compared to other catalysts, with a specific activity of 34.7 mA/cm2 . The electrocatalytic performance of the 3% Cu/CNT catalyst was investigated with different scan rates. It was also found to have the best resistance by electrochemical impedance spectroscopy (EIS) analysis. It has the potential to be a promising anode catalyst for direct hydrazine fuel cells (DHYPs). [ABSTRACT FROM AUTHOR]

The preferential adsorption toward OH− on the anode most likely blocks the accessibility of organic molecules and triggers competitive oxygen evolution reaction (OER), typically precipitating a narrow potential window. Here, an OH− deconfinement strategy enabled by CO32− self‐transformed from C2O42− on metallic nickel oxalate (NiC2O4) for efficient synthesis of bioplastic monomer 2,5‐furanedicarboxylic acid (FDCA) with faradaic efficiency of >95% via electrocatalytic 5‐hydroxymethylfurfural (HMF) oxidation reaction (e‐HMFOR) at a wider potential window of 1.38–1.56 VRHE, outperforming state‐of‐the‐art Ni‐based electrocatalysts is presented. In situ, tests corroborate that the construction of NiOOH with surface‐adsorbed CO32− (NiOOH‐CO32−) from NiC2O4 can be facilitated by self‐liberating CO32−. The CO32− ions serving as an electric field engine can effectively weaken OH− coverage through electrostatic repulsion and enhance HMF adsorption at the NiOOH‐CO32− surface, thereby heightening e‐HMFOR while inhibiting OER. Computational results further indicate that the CO32− on NiOOH hoists the energy barrier of oxygen intermediate conversion (O* → OOH*) to suppress OER but promotes the e‐HMFOR kinetics. The precise modulation of OH− adsorption behavior on the electrocatalyst offers a powerful kit for boosting the oxidative upgrading process while circumventing the competing reaction OER. [ABSTRACT FROM AUTHOR]

The key challenge for 5‐hydroxymethylfurfural oxidation reaction (HMFOR) lies in understanding the synergistic interactions between active sites and adsorption sites, but the uncertain spatial positions of these two sites largely limit their synergistic effect. Here, an embedded Pd/NiFe layered double hydroxide (LDH) with Pd nanoparticles (NPs) (3.6 nm) far larger than the interlayer spacing of LDH is reported, which results in the in situ generation of the defective structures at the interface of the NiFe laminate. The Pd/NiFe shows a lower onset potential of 1.34 V compared to NiFe (1.42 V). Experimental and theoretical calculations reveal that the Pd NPs exhibit a high level of orbital overlap with HMF, leading to a strong adsorption tendency and an increased local concentration of HMF near the Pd NPs. The Ni defects generated around Pd NPs result in the 3d‐orbitals of adjacent Ni sites approaching the Fermi level, reducing the oxidation barrier from Ni2+‐OH to Ni3+‐O active sites. Furthermore, this work provides crucial evidence for the hydration interactions between the aldehyde groups in HMF and the hydroxyl groups on the catalyst surface, demonstrating that the removal ability of the latter one can have an important influence on HMFOR activity. [ABSTRACT FROM AUTHOR]

In this study, the characterization, optimization and effect of model compound Reactive Black 5 (RB5) dye on the process performance of lanthanum (La) and cerium (Ce) doped iridium‐ruthenium (Ir‐Ru) mixed metal oxide (MMO) electrodes were investigated. The electrodes had varying La and Ce doping levels at 5%, 10% and 20% concentrations and were coated by thermal decomposition technique. In addition, a mixed La/Ce electrode was prepared with 10% Ce and 10% La. This study focused on understanding the effects of La and Ce doping, pH, conductivity and concentration on the electrochemical degradation process. The experiments were conducted over various pH values ​​(3, 5, 7 and 9), dye concentrations (50, 100, 300 and 500 ppm), current densities (100, 200, 350 and 600 A.m‐2) and conductivities (1500, 3500, 5500 and 10000 µS.cm−1). It was found that the newly developed electrode doped with 10% Ce and 10% La showed the most efficient results. This study provides insights into optimizing the operational parameters for effective electrochemical process with the novel La/Ce doped MMO electrodes. [ABSTRACT FROM AUTHOR]

Electrodes modified with gold particles, multi-walled carbon nanotubes, an ionic liquid based on 1-butyl-3-methylimidazolium hexafluorophosphate, and a composite derived from these materials have been developed for the voltammetric determination of sulfamethazine, sulfacetamide, and sulfathiazole. Cyclic voltammetry reveals that modifying the surface of a glassy carbon electrode with gold particles, a composite of carbon nanotubes, and an ionic liquid increases its effective surface area. Electrochemical impedance data indicate that the rate of electron transfer on the modified electrodes surpasses that on the unmodified ones. The composite electrode containing gold particles, carbon nanotubes, and the ionic liquid, exhibited the best performance, was utilized for the amperometric determination of sulfonamides in a batch-injection analysis system. Optimal parameters for the determination of sulfonamides in the batch-injection setup were found. The relationship between the analytical signal and the concentration of the compounds on the logarithmic coordinates is linear, ranging from 1 × 10–8 to 5 × 10–3 M for sulfamethazine and sulfacetamide, and from 1 × 10–7 to 5 × 10–3 M for sulfathiazole. The proposed method for determining sulfonamides has been tested in ananalysis of pharmaceutical preparations. [ABSTRACT FROM AUTHOR]

The catalyst for ethylene glycol electrooxidation reaction (EGEOR) is vitally important for direct ethylene glycol fuel cells. Nevertheless, the unsatisfactory EGEOR performance and high-cost of the catalysts still stands as an urgent obstacle that needs to be solved. Herein, we report a fabrication of ceria/nitrogen-doped carbon loaded Pd nanoparticles (Pd–CeO 2 /NC) as an electrocatalyst for EGEOR. During the catalyst synthesis, the renewable and abundant bioresource lignin serves as a precursor to prepare the nitrogen-doped porous carbon (NC), which can save the cost of the carbon support. Ulteriorly, the CeO 2 -doped NC acts as the support to immobilize the Pd nanoparticles by a water-phase reduction approach. Consequently, due to the synergistic effects between the highly-dispersed Pd nanoparticles, CeO 2 and NC, the resultant catalyst affords a current density of 46.39 mA cm−2, which is 2.86 times higher than that of commercial Pd/C (16.22 mA cm−2). Moreover, the developed catalyst also presents better EGEOR stability. This work not only develops a highly active EGEOR catalyst, but also provides an effective method for efficiently utilizing renewable biomass resources. • Multi-component Pd–CeO 2 /NC nanocomposites have been synthesized. • The renewable bioresource lignin serves as precursor for preparing carbon support. • The as-prepared catalysts present superior electrocatalytic performance. [ABSTRACT FROM AUTHOR]

Producing hydrogen through water electrolysis technology is a clean and environmentally friendly method of hydrogen generation. However, the key to realizing the industrial-scale application of water electrolysis for hydrogen production lies in the development of efficient, stable and cost-effective catalysts for the hydrogen evolution reaction. In this work, a nanoporous NiO-Ni/Al3Ni2 composite catalyst was prepared by combining the dealloying method and electrochemical oxidation treatment. Due to the synergistic effects of the Ni, Al3Ni2 and NiO tri-phases, the NiO-Ni/Al3Ni2 composite catalyst exhibited excellent electrocatalytic activity for water splitting and hydrogen evolution. By adjusting the parameters of the electrochemical oxidation treatment, composite catalysts with different compositional ratios could be obtained. Among them, the NiO-Ni/Al3Ni2-10s catalyst showed the optimal hydrogen evolution reaction catalytic performance, requiring only 79.1 mV of overpotential to achieve a current density of 10 mA/cm2 in alkaline media, while also demonstrating excellent long-term stability. This research provides valuable insights and references for the development of high-activity and high-stability nickel-based hydrogen evolution catalysts. [ABSTRACT FROM AUTHOR]

Here, we report the use of highly reproducible free-standing 3D Pt nanowire frameworks (3D Pt NFs) to investigate the electrochemical oxidation of glucose. To create this unique Pt NFs, we utilize a lipidic bicontinuous cubic phase as a template. The resulting Pt NFs exhibits a unique 3D single diamond morphology with Fd3m symmetry. This intricate structure provides a large surface area and high electrocatalytic efficiency, making it more sensitive to glucose detection. Small Angle X-ray Scattering and Transmission electron microscopy investigations provided valuable insights into the nanoarchitecture of 3D Pt NFs. It highlights the interconnected nature of the nanowires and showcases the potential for optimized electrochemical performance. Very high current densities are registered for the glucose oxidation reactions at 3D Pt NFs during cyclic voltammetry investigations. This knowledge aids in the design and development of advanced electrocatalytic systems, fuel cells, biosensors, and other devices that leverage the unique characteristics of the 3D Pt framework. This study explores 3D Pt NFs for electrochemical glucose oxidation. Using a phytantriol template with two non-intersecting aqueous channels (A), Pt is electrodeposited in one channel (B), resulting in the formation of 3D Pt NFs after template washing (C). This approach demonstrates the potential for efficient glucose oxidation in the structured nanowire frameworks. [ABSTRACT FROM AUTHOR]

This study explored electrooxidation pretreatment of reject water and condensate generated using sludge dewatering with goal of improving its treatment using a membrane bioreactor (MBR) and also prevent membrane fouling. Initially the important parameters for electrooxidation process were optimized. The results showed that a total current of 4.03 A/L, current density of 60 mA/cm2, pH 7, and 1500 mg/L of Clion concentration were best in terms of solubilization and removal of fouling-causing substances from wastewater. The colour removal from the wastewater could be as high as 92.4% (7 colour unit (CU) of treated effluent) under optimum operating condition. For biological treatment, a four-tank biological system consisting of consequently placed anoxic and aerobic compartments with final tank containing a MBR was used. When compared with untreated wastewater, the MBR treating EO pretreated wastewater showed significant improvement in terms of membrane fouling measured as transmembrane pressure (TMP). Further improvement in the nitrogen and TOC removal could be achieved by extending the EO treatment duration and subsequent HRT of MBR treatment. The findings from the study clearly demonstrates the potential for integrating a combined electrooxidation and MBR treatment in the conventional wastewater treatment plant for reducing its influent pollutant load. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs), an emerging nanomaterial, have shown significant promise in the materials science. This study aims to electrochemical deposited reduce carbon dots (RCDs) and pectin (PC) scaffold on the pencil graphite electrode (PGE), resulting a multifunctional electrocatalyst support (PC/RCDs/PGE) for electroloading of the nickel nanoparticles (NiNPs) to creates the NiNPs/PC/RCDs/PGE for electrooxidation of ethanol. Comprehensive surface and structural analysis and chemical identification methods were utilized for characterization of the modified electrode. Evaluation as an electrocatalyst for ethanol oxidation in 0.1 M NaOH, demonstrated that the NiNPs/PC/RCDs/PGE shows high electrocatalytic activity (Jp = 112 mA cm−2), outperforming several comparisons modified electrodes, RCDs/PGE, NiNPs/RCDs/PGE, NiNPs/PC/PGE, and NiNPs/PGE. These findings suggest that the RCDs and PC scaffold enhances the electrocatalytic activity of the NiNPs via the increasing the surface area of electrodeposited NiNPs and synergistic effect of nanocomposite components, indicating potential for significant advancements in non-platinum ethanol oxidation electrocatalysts. [Display omitted] • The RCDs were electrodeposited at PGE by electroreduction of the synthesized CDs. •The PC was electrodeposited on/in RCDs/PGE for first time to produce PC/RCDs/PGE. •The NiNPs/PC/RCDs/PGE was prepared by electroloading of NiNPs on/in PC/RCDs/PGE. •The NiNPs/PC/RCDs/PGE was used as a potent electrocatalyst for EOR in 0.1 M NaOH. •The NiNPs/PC/RCDs/PGE displayed high electrocatalytic activity toward EOR in NaOH. [ABSTRACT FROM AUTHOR]

The use of electrocatalytic technology to replace traditional harsh thermocatalysis in the process of biomass utilization has undoubtedly been an effective means to achieve green and sustainable development. The use of the environmentally friendly method of synthesizing furoic acid (FA) from the biomass platform compound furfural (FF) by electrooxidation was investigated. The surface of the Ni–Co oxide electrode with a Ni content of 0.48 (Ni0.48Co0.36O0.16) obtained by a simple electrodeposition method was covered by a layer of flower-like porous structure, while NiO, Co2+, and Co3+ coexisted. Moreover, the Ni0.48Co0.36O0.16 electrode exhibited 95.4% FA faraday efficiency and 99.6% selectivity with a substrate concentration of 20 mM at 1.0 V vs. Hg/HgO and 50 °C. In addition, a mechanism for electrooxidation of FF into FA over a Ni–Co oxide electrode was proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • ·Mo 2 C-FeCu catalyst was designed by thermal reduction and carburization of precursor. • ·cinnamaldehyde/benzalacetone were synthesized at high yields and selectivities. • · α , β -unsaturated aldehyde/ketone were electrosynthesized in gentle and green manner. • ·C C coulping reaction was fulfilled by combined electrochemical-chemical pathway. Oxygen evolution reaction (OER) is the efficiency limiting half-reaction in water electrolysis for green hydrogen production due to the 4-electron multistep process with sluggish kinetics. The electrooxidation of thermodynamically more favorable organics accompanied by C C coupling is a promising way to synthesize value-added chemicals instead of OER. Efficient catalyst is of paramount importance to fulfill such a goal. Herein, a molybdenum iron carbide-copper hybrid (Mo 2 C-FeCu) was designed as anodic catalyst, which demonstrated decent OER catalytic capability with low overpotential of 238 mV at response current density of 10 mA cm−2 and fine stability. More importantly, the Mo 2 C-FeCu enabled electrooxidation assisted aldol condensation of phenylcarbinol with α -H containing alcohol/ketone in weak alkali electrolyte to selective synthesize cinnamaldehyde/benzalacetone at reduced potential. The hydroxyl and superoxide intermediate radicals generated at high potential are deemed to be responsible for the electrooxidation of phenylcarbinol and aldol condensation reactions to afford cinnamaldehyde/benzalacetone. The current work showcases an electrochemical-chemical combined C C coupling reaction to prepare organic chemicals, we believe more widespread organics can be synthesized by tailored electrochemical reactions. [ABSTRACT FROM AUTHOR]

Abstract Palm oil mill effluent (POME), wastewater generated from palm oil production, is known for its extremely high chemical oxygen demand and brownish color. Anaerobic digestion is the primary treatment method for POME in the palm oil industry; however, anaerobically treated POME has high concentrations of residual contaminants and color intensity. This study proposes an approach to treat anaerobically-treated POME in recycled water for industrial applications by integrating preliminary organic precipitation, electrocoagulation, and electrooxidation (EO). The EO process was optimized in terms of the current density, electrolysis time, electrode arrangement, and feed flow rate. At a current density of 60 mA/cm2 and an electrolysis time of 9 min, the EO process with a graphite anode and stainless-steel cathode in the monopolar electrode configuration reduced the phenolic concentration and color in the preliminary-treated POME from 8.95 mg/L and 317.19 ADMI to 0.25 mg/L and 26.10 ADMI, respectively. Additionally, the EO process exhibited a 92.26% efficiency in lowering the ammonium-nitrogen content.

The electrooxidation of catalyst surfaces is across various electrocatalytic reactions, directly impacting their activity, stability and selectivity. Precisely characterizing the electrooxidation on well‐defined surfaces is essential to understanding electrocatalytic reactions comprehensively. Herein, we employed in situ Raman spectroscopy to monitor the electrooxidation process of palladium single crystal. Our findings reveal that the Pd surface's initial electrooxidation process involves forming *OH intermediate and ClO4− ions facilitate the deprotonation process, leading to the formation of PdOx. Subsequently, under deep electrooxidation potential range, the oxygen atoms within PdOx contribute to creating surface‐bound peroxide species, ultimately resulting in oxygen generation. The adsorption strength of *OH and the coverage of ClO4− can be adjusted by the controllable electronic effect, resulting in different oxidation rates. This study offers valuable insights into elucidating the electrooxidation mechanisms underlying a range of electrocatalytic reactions, thereby contributing to the rational design of catalysts. [ABSTRACT FROM AUTHOR]

The production of green hydrogen is one of the most demanding and challenging for modern technology. A promising and an effective approach is electrocatalytic anodic urea oxidation reaction to generate hydrogen at cathode under alkaline electrolysis condition. However, it remains crucial for the development of active and stable electrocatalysts for efficient urea oxidation. In this study, we employed the hydrothermal synthesis route for NiFe LDH, NiFe LDO, and Ni(OH) 2. The superior performance of NiFe LDH compared to other catalysts is observed due to easy charge transfer facilitated by Fe ions. Moreover, Fe incorporation prevents surface poisoning of the electrocatalyst, resulting in increased activity and stability for electrocatalytic urea oxidation reaction. The influence of different electrolyte environments on the performance of urea-based electrolyzers for sustainable hydrogen production and management of urea-rich wastewater has been measured for the first time by varying oxygen saturation and nitrogen purging conditions. In cyclic voltammetry studies, O 2 -saturated and purging conditions outperformed N 2 gas saturation or purging. The findings of this study provide valuable insight into the design of practical and environmentally friendly urea electrooxidation systems. Continuous O 2 purging enhances urea electrooxidation effectively and efficiently with NiFe LDH. [Display omitted] • An investigation of the effect of electrolyte environment for efficient urea electrooxidation. • NiFe LDH offers greater electrocatalytic activity for UOR compared to NiFe LDO and Ni(OH) 2. • Oxidation reaction switches due to NaOH concentration and promotes enhanced urea electrooxidation. • Urea electrooxidation is enhanced by oxygen saturation and purging by releasing more OH- ions. • Nyquist and Bode plots analysis at wide potential range and varying electrolyte conditions. [ABSTRACT FROM AUTHOR]

Palm oil mill effluent (POME), wastewater generated from palm oil production, is known for its extremely high chemical oxygen demand and brownish color. Anaerobic digestion is the primary treatment method for POME in the palm oil industry; however, anaerobically treated POME has high concentrations of residual contaminants and color intensity. This study proposes an approach to treat anaerobically-treated POME in recycled water for industrial applications by integrating preliminary organic precipitation, electrocoagulation, and electrooxidation (EO). The EO process was optimized in terms of the current density, electrolysis time, electrode arrangement, and feed flow rate. At a current density of 60 mA/cm2 and an electrolysis time of 9 min, the EO process with a graphite anode and stainless-steel cathode in the monopolar electrode configuration reduced the phenolic concentration and color in the preliminary-treated POME from 8.95 mg/L and 317.19 ADMI to 0.25 mg/L and 26.10 ADMI, respectively. Additionally, the EO process exhibited a 92.26% efficiency in lowering the ammonium-nitrogen content. [ABSTRACT FROM AUTHOR]

5‐Hydroxymethylfurfural (HMF) is a widely used biomass platform chemical that plays a crucial role in bridging biomass and fossil resources. Electrocatalytic oxidation of HMF provides an efficient way to obtain high‐value‐added biomass‐derived chemicals, among which the intermediate product 5‐formyl‐2‐furan carboxylic acid (FFCA) has attracted considerable attention. However, the weak adsorption ability of monometallic nickel oxide (NiOx) to HMF in neutral electrolyte restricts its further development, resulting in low HMF conversion and FFCA yield. In this study, we successfully constructed a novel nickel oxide‐platinum oxide hybrid catalyst supported on carbon felt (NiOx‐PtOx/CF), which exhibits an optimized adsorption ability of HMF, leading to the outstanding FFCA yield up to 77 % in the neutral media. The high activity of the NiOx‐PtOx/CF catalyst can be attributed to the redistribution of the electrons and the optimization of the electronic structure on the Ni active site due to the introduction of PtOx on NiOx nanosheets. This study offers valuable insights for the design of efficient multicomponent electrocatalysts for electrocatalytic biomass refinery systems. [ABSTRACT FROM AUTHOR]

Electrochemical biomass oxidation coupled with hydrogen evolution offers a promising route to generate value‐added chemicals and clean energy. The complex adsorption behavior of 5‐hydroxymethyl furfural (HMF) and hydroxyl ions (OH−) on the electrocatalyst surface during HMF electrooxidation reaction (HMFOR) necessitates an in‐depth understanding of active sites available for adsorption. Herein, oxygen vacancy (VO) defects are introduced in NiFe layered double hydroxide (LDH) using Ce dopants to manipulate electronic structure. Synchrotron‐based HE‐XRD and XAS indicate negligible VO in La‐doped NiFe while Ce doping leads to VO defects due to flexible Ce redox (Ce3+↔ Ce4+). The VO‐rich Ce‐NiFe exhibits higher Faradic efficiency of ≈90% to produce 2,5‐furan dicarboxylic acid (FDCA), far greater than ≈60% for NiFe VO in Ce‐NiFe act as alternative active sites for OH− adsorption, hence reducing adsorption competition for the same metal sites. DFT calculation results corroborate experimental findings by showcasing that the presence of VO in Ce‐NiFe manipulates the adsorption energies and facilitates the chemical adsorption OH− in VO to improve HMFOR. In situ HE‐XRD derived pair distribution function coupled to RMC simulations confirm OH− trapping in VO and HMF adsorption on metal centers as evident by interlayer distance evolution. Taken together, this work showcases routes for dual‐site electrocatalyst design for improved biomass electrooxidation. [ABSTRACT FROM AUTHOR]

Ni-doped CoTe nanorods have been prepared for 5-hydroxymethylfurfural oxidation reaction. The doping of Ni facilitates the oxidation of Co2+ to high-valent CoO 2 to achieve efficient electrosynthesis of the valuable 2,5-furandicarboxylic acid. [Display omitted] • A crude nanorod structure CoNiTe was prepared by two-step hydrothermal reactions for HMFOR. • Ni doping modulates the electronic structure of Co and improves the electrocatalytic performance of CoNiTe. • The generation of high-valent cobalt is the key for excellent HMFOR. Replacing the anodic oxygen evolution reaction (OER) in water splitting with 5-hydroxymethylfurfural oxidation reaction (HMFOR) can not only reduce the energy required for hydrogen production but also yield the valuable chemical 2,5-furandicarboxylic acid (FDCA). Co-based catalysts are known to be efficient for HMFOR, with high-valent Co being recognized as the main active component. However, efficiently promoting the oxidation of Co2+ to produce high-valent reactive species remains a challenge. In this study, Ni-doped CoTe (CoNiTe) nanorods were prepared as efficient catalysts for HMFOR, achieving a high HMFOR current density of 65.3 mA cm−2 at 1.50 V. Even after undergoing five successive electrolysis processes, the Faradaic efficiency (FE) remained at approximately 90.7 %, showing robust electrochemical durability. Mechanistic studies indicated that Ni doping changes the electronic configuration of Co, enhancing its charge transfer rate and facilitating the oxidation of Co2+ to high-valent CoO 2 species. This work reveals the effect of Ni doping on the reconfiguration of the active phase during HMFOR. [ABSTRACT FROM AUTHOR]

The present study details a more environmentally friendly method for synthesizing iron oxide nanoparticles (Fe3O4‐NPs) utilizing Hibiscus sabdariffa (H. sabdariffa) leaf extract. The produced H. sabdariffa/Fe3O4‐NPs underwent characterization through VSM, XRD, FESEM‐EDX, TEM and FTIR analyses. The FESEM and TEM images revealed that the H. sabdariffa/Fe3O4‐NPs had a narrow distribution and an average particle size of 5±2 nm. Catalytic degradation studies of the synthesized Fe3O4‐NPs exhibited efficient reduction of methyl orange (MO) dye. The degradation of MO catalysed by H. sabdariffa/Fe3O4‐NPs follow the pseudo‐first order kinetics, with a rate constant of 0.0328 s−1 (R2=0.9866). Moreover, in electrochemical sensing studies, the anodic peak current of nitrite (NO2−) for H. sabdariffa/Fe3O4‐NPs/GCE showed a linear relationship with its concentration within the range of 0.5–7.5 mM, achieving a detection limit of 0.29 μM. These findings demonstrate that the modified electrode with Fe3O4‐NPs synthesized using H. sabdariffa leaf extract serve as a novel electrochemical sensor for determining NO2− with high sensitivity and reproducibility. [ABSTRACT FROM AUTHOR]

• Iron addition raised the removal efficiency of ciprofloxacin from 65 to 94%. • Electro-activated persulfate (EAP) with iron addition process is cost-effective. • EAP+Fe process is superior to EAP for ciprofloxacin removal. • Three ciprofloxacin intermediates were reported for the first time in this study. Ciprofloxacin (CIP) is a commonly used antibiotic in the fluoroquinolone group and is widely used in medical and veterinary medicine disciplines to treat bacterial infections. When CIP is discharged into the sewage system, it cannot be removed by a conventional wastewater treatment plant because of its recalcitrant characteristics. In this study, boron-doped diamond anode and persulfate were used to degrade CIP in an aquatic solution by creating an electrochemically activated persulfate (EAP) process. Iron was added to the system as a coactivator and the process was called EAP+Fe. The effects of independent variables, including pH, Fe2+, persulfate concentration, and electrolysis time on the system were optimized using the response surface methodology. The results showed that the EAP+Fe process removed 94% of CIP under the following optimum conditions: A pH of 3, persulfate/Fe2+ concentration of 0.4 mmol/L, initial CIP concentration 30 mg/L, and electrolysis time of 12.64 min. CIP removal efficiency was increased from 65.10% to 94.35% by adding Fe2+ as a transition metal. CIP degradation products, 7 pathways, and 78 intermediates of CIP were studied, and three of those intermediates (m/z 298, 498, and 505) were reported. The toxicological analysis based on toxicity estimation software results indicated that some degradation products of CIP were toxic to targeted animals, including fathead minnow, Daphnia magna, Tetrahymena pyriformis , and rats. The optimum operation costs were similar in EAP and EAP+Fe processes, approximately 0.54 €/m3. [Display omitted] [ABSTRACT FROM AUTHOR]

Comprehensive Summary: An efficient electrochemical approach has been developed for the construction of 3‐sulfanylquinoline derivatives by treating phenylethynylbenzoxazinanones with disulfides in an undivided cell. The protocol provided a convenient route to functionalized quinolines with good functional group tolerance. Moreover, it does not require any metal catalysts or additives, furnishing a series of biological quinolines in moderate to good yields. [ABSTRACT FROM AUTHOR]

Electrocatalytic alcohol oxidation (EAO) is an attractive alternative to the sluggish oxygen evolution reaction in electrochemical hydrogen evolution cells. However, the development of high-performance bifunctional electrocatalysts is a major challenge. Herein, we developed a nitrogen-doped bimetallic oxide electrocatalyst (WO-N/NF) by a one-step hydrothermal method for the selective electrooxidation of benzyl alcohol to benzoic acid in alkaline electrolytes. The WO-N/NF electrode features block-shaped particles on a rough, inhomogeneous surface with cracks and lumpy nodules, increasing active sites and enhancing electrolyte diffusion. The electrode demonstrates exceptional activity, stability, and selectivity, achieving efficient benzoic acid production while reducing the electrolysis voltage. A low onset potential of 1.38 V (vs. RHE) is achieved to reach a current density of 100 mA cm−2 in 1.0 M KOH electrolyte with only 0.2 mmol of metal precursors, which is 396 mV lower than that of water oxidation. The analysis reveals a yield, conversion, and selectivity of 98.41%, 99.66%, and 99.74%, respectively, with a Faradaic efficiency of 98.77%. This work provides insight into the rational design of a highly active and selective catalyst for electrocatalytic alcohol oxidation. [ABSTRACT FROM AUTHOR]

Modified electrodes based on gold particles, mixed-valence ruthenium oxides, and a binary system combining these components were developed for the voltammetric determination of ceftriaxone, cefotaxime, and cefoperazone. The electrode with the binary system of gold particles and mixed-valence ruthenium oxides, which exhibited the best performance, was used for the detection of cephalosporins in flow-injection analysis. Optimal conditions for the detection of cephalosporins in a flow-injection system were selected. The dependence of the analytical signal on the concentration of the compounds under consideration is linear on logarithmic coordinates over the range from 5 × 10–7 to 5 × 10–3 M. The proposed procedure was tested in the determination of cephalosporins in pharmaceuticals. [ABSTRACT FROM AUTHOR]

Electrochemical study of the mechanism of dimethylsulfoxide electrooxidation on a platinum electrode in acidic and alkaline solutions is carried out. On the stationary anodic polarization curves taken in acidic and alkaline dimethylsulfoxide solutions, the oxidation currents preceded those measured in the supporting electrolyte. By the analyzing of linear segments of anodic voltammograms, the coefficients of the Tafel equation are determined. This allowed choosing the current density range and conditions for the dimethylsulfoxide electrooxidation on the platinum electrode. The electrolysis was carried out at controlled current density in electrolyzers both with unseparated compartments and the anodic and cathodic compartments separated with MK-40, MA-40 membranes and a MF-4SK fluoropolymer sulfocationite membrane. The high electrical conductivity and selectivity of the membranes provided good performance of the electrolysis process and obtaining of high-purity final product. Raman spectroscopy and gas chromatography–mass spectrometry confirmed that the products of dimethylsulfoxide electrooxidation in the acidic solution are dimethylsulfone and dimethylsulfoxide; in alkaline solution, the dimethyl sulfone and sodium methanesulfonate. The method of quantum-chemical calculations showed good adsorption of dimethylsulfoxide molecules at platinum within the frames of the cluster model. It is shown that the dimethylsulfoxide formation at the platinum electrode surface at high current densities occurs by the radical-ion mechanism, involving breaking of the C–S bond. Based on the experimental results obtained, a scheme for the dimethylsulfoxide electrochemical oxidation at platinum is proposed. [ABSTRACT FROM AUTHOR]

Sunitinib is a targeted therapy for colorectal cancer, which needs a precise dosage due to potential severe side effects from overdose. Therapeutic drug monitoring is crucial for maintaining optimal drug levels in body fluids. Traditional anticancer drug dose evalua­tion methods such as high-pressure liquid chromatography, liquid chromatography with mass spectrophotometry, and immunoassays are cumbersome. This study explores the utilization of electrochemical sensors on indigenously developed screen-printed electrodes for sunitinib malate monitoring. Differential pulse voltammetry, cyclic voltam­metry and chrono-amperometric studies were conducted in a conventional three-elec­trode system. An anodic peak current, indicative of sunitinib malate electro­oxi­dation, was observed around +0.45 V vs. Ag/AgCl reference electrode in 0.1 M PB of pH 7.4. Sen­sitivity, the limit of detection and method detection limit were determined as 0.386 µA µM-1 cm-2, 0.009 and 0.0108 µM, respectively. The response exhibited linearity (R2 = 0.990) with sunitinib concentration ranging from 0.08 to 88 μM with good reproducibility. DPV studies on real samples yielded acceptable recovery values. Electro­chemical sensors based on the screen-printed electrode present a promising approach for sunitinib monitoring, offering sensitivity, low limit of detection, and a wide linear range. Since the expected plasma concentration of sunitinib is much higher than the sensor detection range, it can be used for real sample analysis. Here developed methods could simplify and improve therapeutic drug monitoring in colorectal cancer treatment.

An unprecedented electrochemical oxidative trifunctionalization of olefins with diaryl disulfides/aryl thiols and N-chlorosuccinimide in an aqueous system is developed. Two C–Cl bonds, one C–S bond, and one SO bond are produced simultaneously in one step from simple and commercially available starting materials with clean energy. This tandem methodology features as mild reaction conditions, transition metal and additional oxidant free, broad substrate scope, good functional group compatibility, and gram scale preparation.

In this study, trimethylolpropane triglycidyl ether/diethylenetriamine (TD) and glutaraldehyde/diethylenetriamine (GD) polymer particles are synthesized as catalysts for hydrogen production from NaBH4 methanolysis and NaBH4 electrooxidation. SEM, FT‐IR and TGA characterization methods are applied to determine the surface morphologies, chemical structures, thermal stability and decomposition of the synthesized polymer particles. The parameters affecting the hydrogen generation rate on NaBH4 methanolysis are investigated and optimum conditions are determined. Under optimum conditions, the hydrogen generation rates of TD and GD polymer particles are obtained as 34903.2 and 97998 mL/min.gcat, respectively. The activation energies of TD and GD polymer particles are also calculated as 16.86 and 18.14 kJ/mol, respectively. The catalytic activities of polymer particles as anode catalysts in NaBH4 electrooxidation are determined by CV, CA, EIS analyses. The specific activities of TD and GD polymer particles are acquired as 0.54 and 0.64 mA/cm2, respectively. These results indicate that the synthesized polymer particles are promising catalysts for electrooxidation and methanolysis of sodium borohydride. [ABSTRACT FROM AUTHOR]

Naringenin (NRG), a flavanone compound present in citrus fruits, has a variety of beneficial physiological active functions such as antioxidant, anti-inflammatory, and hypoglycaemic. In this study, an sensor was constructed by electrodeposition and used for the electrochemical study of NRG. Reduced graphene oxide (rGO) and glutathione (GSH) showed the ability to synergistically amplify NRG signals and possessed good linearity in the concentration range of 10.00–1200.00 μ mol l−1. The linear equation is Ip = 0.0776logc + 0.9353 (R2 = 0.9901), and the limit of detection is 3.33 μ mol l−1. The sensor performed well in terms of reproducibility, stability, and selectivity, which in turn enabled the detection of NRG in tomatoes. The average recovery of the sensor is 95.68% to 111.92%, with RSD less than 11.89%. The results were also verified by Ultraviolet–visible spectroscopy(UV-vis). Furthermore, density-functional theory was employed to analyse the front track of the NRG, speculating that the NRG underwent a transfer of two electrons and two protons. [ABSTRACT FROM AUTHOR]

Correlating dynamic structural transformation of catalysts with the surface intermediate species under operating conditions is critical for updating the understanding of structure–performance relationships. Here, we probe the electrochemical potential-dependent surface structures and adsorbed intermediates on PtRu binary alloy nanocatalysts to revisit its synergistic mechanisms for CO electrooxidation enhanced activity. In-situ spectral characteristics by using modified shell-isolated nanoparticle-enhanced Raman spectroscopy, show that in acidic solution, when the potential is positively scanned from 0.1 V to 1.5 V relative to reversible hydrogen electrode (RHE), the surface of the alloy catalyst evolves from metallic PtRu to adsorbed oxygen gradually covering and accumulating on Ru sites (denoted as PtRuOx, x⩽2), forming segregated RuO2, and finally forming a three-dimensional oxide layer (denoted as 3D PtRuO4). Moreover, molecular evidence associated with periodic density functional theory calculations reveals that electronic effects promote ruthenium to become more oxidizable and oxophilic. In particular, we found here that *O and *OH at surface RuOx sites are highly efficient CO oxidation active species in comparison to the same entities adsorbed on metallic Ru sites. This work sheds light on the complex surface dynamic process of practical Pt-based binary nanocatalysts and improves the understanding of synergistic mechanism for the development of fuel cell devices. [ABSTRACT FROM AUTHOR]

The selective electrooxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is of great significance in replacing terephthalic acid for the production of high-performance polymeric materials. This necessitates the development of advanced electrocatalysts. Ni-based nanomaterials, known for their unique electronic structure and high intrinsic activity, show great promise for the selective electrooxidation of HMF to FDCA. To provide guidance for the further development of advanced HMF electrocatalysts, we present a comprehensive review of recent progress in this field, focusing on HMFOR mechanisms, effective engineering strategies (e.g., morphology design, defect engineering, interface engineering, and strain engineering) for improving electrocatalytic performance, and representative Ni-based catalysts used for HMFOR. Finally, we offer a conclusion and highlight the challenging issues that need to be addressed, providing researchers with direction for future endeavors. • A review on the oxidation of HMF into FDCA catalyzed by Ni-based materials is summarized. • The mechanisms of HMF electrooxidation are described thoroughly. • Strategies for optimizing the catalytic performance of Ni-based materials for HMFOR are mentioned. • Recent progresses, challenges, and perspectives are highlighted. [ABSTRACT FROM AUTHOR]