Search Results (540)

Electrocatalytic CO₂ reduction reaction (CO₂RR) is a crucial technology for achieving carbon cycling and renewable energy conversion, yet it faces challenges such as complex reaction pathways, competition for intermediate adsorption, and low product selectivity. In recent years, molecular modification has emerged as a promising strategy. By adjusting the surface properties of catalysts, molecular modification alters the electronic structure, steric hindrance, promotes the adsorption of reactants, stabilizes intermediates, modifies the hydrophilic–hydrophobic environment, and regulates pH, thereby significantly enhancing the conversion efficiency and selectivity of CO₂RR. This paper systematically reviews the modification strategies and mechanisms of molecularly modified materials in CO₂RR. By summarizing and analyzing the existing literature, this review provides new perspectives and insights for future research on molecularly modified materials in electrocatalytic CO₂ reduction. Full article

The electrochemical reduction of carbon monoxide (COER) offers a promising route for generating value-added multi-carbon (C₂₊) products, such as ethanol, but achieving high catalytic performance remains a significant challenge. Herein, we performed comprehensive density functional theory (DFT) computations to evaluate CO-to-ethanol conversion on single metal atoms anchored on graphitic carbon nitride (TM/g–CN). We showed that these metal atoms stably coordinate with edge N sites of g–CN to form active catalytic centers. Screening 20 TM/g–CN candidates, we identified V/g–CN and Zn/g–CN as optimal catalysts: both exhibit low free-energy barriers (<0.50 eV) for the key ^*CO hydrogenation steps and facilitate C–C coupling via an Eley–Rideal mechanism with a negligible kinetic barrier (~0.10 eV) to yield ethanol at low limiting potentials, which explains their superior COER performance. An analysis of d-band centers, charge transfer, and bonding–antibonding orbital distributions revealed the origin of their activity. This work provides theoretical insights and useful guidelines for designing high-performance single-atom COER catalysts. Full article

Reducing atmospheric carbon dioxide is a critical global priority. This study investigates the influence of Cu-Ni nanoalloy loading on the CO₂ electroreduction efficiency in the context of mesoporous carbon supports. Current methods struggle when it comes to catalyst efficiency, selectivity, and longevity. By synthesizing copper–nickel nanoparticles through chemical reduction and depositing them on porous carbon, this research aimed to optimize catalyst loading and understand the structure–activity relationships. Catalyst performance was evaluated using chronoamperometry and linear sweep voltammetry (LSV). The results showed that 12 wt% catalyst loading achieved optimal CO₂ reduction, outperforming its 36 wt% counterpart by balancing the catalyst quantity. This study reveals that 12 wt% Cu-Ni loading provides a higher CO₂ reduction current density and greater long-term stability than 36 wt% loading, owing to better nanoparticle dispersion and reduced aggregation. Unlike previous Cu-Ni/mesoporous carbon studies, this work uniquely compares different loadings to directly correlate the structure, electrochemical performance, and catalyst durability. Full article

Fe and Cu powders were mixed at a 50:50 ratio. Then, Fe-Cu alloys were prepared using the ball milling technique with different milling times of 6, 12, 18, 24, 30, 36, and 42 h. The crystalline structure was analyzed using X-ray diffraction (XRD), and it was found that the optimum milling time was 30 h. The homogeneity of the Fe and Cu elements in the Fe–Cu alloys was analyzed using the scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM–EDX) mapping technique. Additionally, the crystal orientation of the Fe–Cu alloys was investigated using transmission electron microscopy (TEM). To fabricate the cathode for nitrate removal via electrolysis, an Fe–Cu alloy milled for 30 h was deposited onto a copper substrate using mechanical milling, then annealed at 800 °C. A pulsed DC electrolysis method was developed to test the nitrate removal efficiency of the Fe–Cu-coated cathode. The anode used was an Al sheet. The synthesized wastewater was prepared from KNO₃. Nitrate removal experiments from the synthesized wastewater were performed for durations of 0–4 h. The results show that the nitrate removal efficiency at 4 h was 96.90% compared to 74.40% with the Cu cathode. Full article

This study systematically investigates the axial compression capacity calculation method for 7075-T6 aluminum alloy rectangular hollow section (RHS) members based on the Continuous Strength Method (CSM). Axial compression tests were conducted on nine RHS specimens using a YAW-500 electro-hydraulic servo testing machine, and nonlinear finite element models considering material plasticity and geometric imperfections were established using ABAQUS/CAE. The numerical results showed good agreement with experimental data, verifying the model’s reliability. Parametric analysis was then performed on RHS members, leading to the development of a CSM-based capacity calculation method and a modified curve for predicting the stability reduction factors of square hollow section members. The approach combining this modified curve with Chinese codes is termed the Modified Chinese Code Method. The axial capacities calculated by the CSM-based method, Modified Chinese Code Method, EN 1999-1-1, and AASTM were compared for accuracy evaluation. The conclusions indicate that the proposed modified curve provides more accurate predictions of stability coefficients for square tubes, and the CSM-based method yields more precise capacity predictions than existing international design codes, though it may overestimate the capacity for Class 4 cross-section members and thus requires further refinement. Full article

This study focuses on the design and optimization of a monopolar electrode configuration for the hybrid electrochemical treatment of real washing machine wastewater. A combined electrocoagulation (EC) and electro-oxidation (EO) system was optimized to maximize pollutant removal efficiency while minimizing energy consumption. The monopolar setup employed mixed metal oxide (MMO) and aluminum anodes, along with a stainless steel cathode, operating under controlled conditions with sodium chloride as the supporting electrolyte. An applied current density of 15 mA cm⁻² achieved 90% chemical oxygen demand (COD) removal, 98% surfactant degradation, complete turbidity reduction within 120 min, and pH stabilization near 8. Additionally, electrochemical disinfection achieved <2 MPN/100 mL, with no detectable phenols and the presence of organic anions such as oxalate and acetate. These results demonstrate the effectiveness of an optimized monopolar EC–EO system as a cost-efficient and sustainable strategy for wastewater treatment and potential water reuse. Further studies should focus on refining energy consumption and monitoring reaction by-products to enhance large-scale applicability. Full article

An electrochemical immunosensor for the quantification of prostate-specific antigens (PSAs) using silver nanocrystals (AgNCs) is reported. The silver nanocrystals were synthesized using a conventional citrate reduction protocol. The silver nanocrystals were characterized using scanning electron microscopy (SEM) and field effect scanning electron microscopy (FESEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), Fourier-transform infrared spectroscopy (FTIR), UV-Vis spectroscopy, and small-angle X-ray scattering (SAXS). The proposed immunosensor was fabricated on a glassy carbon electrode (GCE), sequentially, by drop-coating AgNCs, the electro-deposition of EDC-NHS, the immobilization of anti-PSA antibody (Ab), and dropping of bovine serum albumin (BSA) to prevent non-specific binding sites. Each stage of the fabrication process was characterized by cyclic voltammetry (CV). Using square wave voltammetry (SWV), the proposed immunosensor displayed high sensitivity in detecting PSA over a concentration range of 1 to 10 ng/mL with a detection limit of 1.14 ng/mL and R² of 0.99%. The immunosensor was selective in the presence of interfering substances like glucose, urea, L-cysteine, and alpha-methylacyl-CoA racemase (AMACR) and it showed good stability and repeatability. These results compare favourably with some previously reported results on similar or related technologies for PSA detection. Full article

The galvanostatic electrodeposition of zinc on carbon paper from mildly acidic solutions (ZnCl₂: 0.05–0.1 M; H₃BO₃: 0.05 M) was investigated. The deposits’ growth mechanisms were analyzed through the study of the electrodeposition potential transients and the physical characterization of the electrodes synthesized by varying the current density, transferred charge, and zinc precursor concentration. The analysis reveals that the transition from crystalline to amorphous mossy deposits takes place via the electrodeposition of metallic zinc followed by the formation of oxidized zinc structures. The time required for this transition can be controlled by varying the zinc precursor concentration and electrodeposition current density, allowing for the synthesis of composite zinc/oxidized zinc electrodes with varying ratios of the oxidized to underlying metallic phases. The impact of this ratio on the electrode activity for CO₂ electroreduction is analyzed, highlighting that composite zinc/oxidized zinc electrodes can achieve a faradaic efficiency to CO equal to 82% at −1.8 V vs. Ag/AgCl. The mechanisms behind the variations in the catalytic activity with varying morphologies and structures are discussed, providing guidelines for the synthesis of composite zinc/oxidized zinc electrodes for CO₂ electroreduction. Full article

This paper presents a systematic analysis of the solid products formed during the cathodic decomposition of chalcopyrite using the acetic acid system. The reduction of chalcopyrite was assessed using different electrochemical and surface characterization techniques. The effect of multiple cathodic polarizations of chalcopyrite immersed in acetic acid was evaluated on the formation of less refractory copper species through the interaction of chalcopyrite with monoatomic hydrogen. The reduction products obtained were characterized by the FESEM/EDS techniques. The results revealed that the iron content in the chalcopyrite lattice was continuously decreased and released into the acetic acid solution when the polarization cycles were increased from 1 to 11 starting from OCP to −2.2 V vs. SHE. The chemical analyses revealed that iron released into the solution corresponds to 0.085 and 1.95 mg/L for 1 and 11 cycles, respectively. The open circuit potential (OCP) measurements of the solid products were shifted to more cathodic potentials than that of chalcopyrite, confirming the possibility to form less refractory species in this weak organic acid. Finally, the FESEM-EDS and XRD analyses showed that chalcopyrite refractoriness decreased, producing Cu, Cu₂S, CuS, CuO, and C₄H₆CuO₄H₂O species depending on the applied energetic condition. Full article

Co(II) complexes have shown promising applications as single-molecule magnets (SMMs) in quantum computing and structural biology. Deciphering the Co(II) complexes may facilitate the development of SMM materials. Structural optimizations and calculations of chemical and magnetic properties were performed for Co(II) complexes with a tripodal tetradentate phenolate-amine ligand using MP2/aug-cc-pvdz, MP2/Def2svp, and CASSCF/Def2svp methods. The Second Order Perturbation Theory Analysis of Fock Matrix in NBO Basis unravels that Co(II) ions form unusual coordinate quasi-double bonds with ligand oxygen donor atoms, and the bond strengths range from 142.01 kcal/mol to 167.36 kcal/mol but lack further spectrometric evidence. The average 151.70 kcal/mol of the Co(II-O coordinates quasi-double bonds are formed mainly by two lone pairs of electrons from the ligand phenolate donor oxygen atoms. Dispersion forces contribute 24%, 28%, 27%, and 31% to the Co(II)-ligand interaction. Theoretical results of ZFS D, transversal ZFS E, and g-factor agree well with the experimental values. Magnetic susceptibility parameters calculated based on 5 doublet roots account for 85% of results computed 40 doublet roots are specified. These insights may aid in the rational design of SMM materials and Co(II) porphyrin fullerene conjugate for CO₂ electroreduction with superior magnetic properties. Full article

The aim of the study was to investigate the influence of L-DOPA—the gold standard in the treatment of Parkinson’s disease symptoms—on the electroreduction kinetics of Zn²⁺ ions. It was demonstrated that this effect depends not only on the concentration of the drug but also on the environment in which the process takes place. In the experimental part, cyclic voltammetry (CV), square wave voltammetry (SWV), direct current polarography (DC), and electrochemical impedance spectroscopy (EIS) were used. Based on the obtained results, it was determined that the analyzed electrode reaction, both in the absence and presence of L-DOPA, proceeded in two steps. The kinetic parameters of Zn²⁺ ion electroreduction indicated its quasi-reversible nature in solutions with both pH = 2.0 and pH = 6.0. The presence of the drug in the lower pH solution resulted in a slight slowing down of the electrode process, whereas in the pH = 6.0 solution, it led to a significant acceleration. In both low and high pH solutions, the first step was slower and determined the rate of the entire electrode process. Full article

With increasing energy demand and depletion of fossil fuels, the search for renewable energy sources has become imperative. Among them, biomass energy has attracted significant attention as it is clean, renewable, and abundant. This review summarizes recent advances in the electroreduction of the biomass-derived platform compound furfural (FF) for producing high-value fuels and chemicals. First, the principles and mechanisms of electrocatalysis are introduced, followed by a detailed analysis of reaction pathways for electrocatalytic hydrogenation, hydrogenolysis, and dimerization. Subsequently, the review highlights the research progress on the electrochemical reduction of FF to hydrofuroin (HDF, a precursor for jet fuel), analyzing its reaction mechanisms and summarizing the effects of catalytic materials and reaction conditions on product selectivity and faradaic efficiency. Additionally, it provides an overview of catalyst selection for both hydrogenation and hydrogenolysis processes. Studies indicate that Cu-based catalysts exhibit superior performance in hydrogenation and hydrogenolysis, with the latter being more favorable under low pH. In contrast, metal-doped carbon catalysts demonstrate enhanced activity in dimerization reactions. Reaction conditions also significantly influence product distribution, with lower reduction potentials generally favoring dimerization. Finally, the challenges and future directions in FF electroreduction are discussed, including the need for deeper understanding of competing pathways, improved electrode stability, and scalable reactor design. The integration of electrocatalytic with renewable energy offers a green and sustainable approach for the efficient utilization of biomass-derived compounds, holding substantial research significance and application potential. Full article

Under low-temperature conditions, the load-bearing capacity of piezoelectric stacks arises from coupled thermo-electro-mechanical interactions, with temperature fluctuations, compressive prestress, and excitation voltage critically modulating performance. This study introduces an integrated measurement platform to systematically quantify these interdependencies, employing a cantilever-based sensing mechanism where bending strain serves as a direct metric of load-bearing capacity. A particle swarm-optimized theoretical framework guides the spatial configuration of actuators and sensors, maximizing strain signal fidelity while suppressing noise interference. Experimental characterization reveals three key findings: 1. Voltage-dependent linear enhancement of load-bearing capacity across all operational regimes, unaffected by thermal or mechanical variations; 2. Prestress-induced amplification (79–90% increase from 0 to 6 MPa) and thermally driven attenuation (15–30% reduction from 20 to −70 °C) of static performance; 3. Frequency-dependent degradation (1–6 Hz) in dynamic load-bearing capacity. The methodology establishes a robust foundation for designing multiphysics-compatible instrumentation systems, enabling precise evaluation of smart material behavior under extreme coupled-field conditions. Full article

To enhance energy efficiency and reduce emissions in public transportation systems, this study proposes a novel electro-hydraulic energy-regenerative suspension system for urban buses. A comprehensive co-simulation framework was established to evaluate system performance. Targeting ride comfort and energy regeneration performance as dual optimization objectives, we conducted systematic parameter analysis through design-of-experiments methodology to identify critical structural parameters. To streamline multi-objective optimization processes, a particle swarm optimization–back propagation (PSO-BP) neural network surrogate model was developed to approximate the complex co-simulation system. Subsequent non-dominated sorting genetic algorithm II (NSGA-II) implementation enabled effective multi-objective optimization of key suspension parameters. Comparative simulations revealed that the optimized configuration achieves the following: (1) maintains ride comfort within human perception thresholds despite slight performance reduction, (2) enhances energy recovery efficiency, and (3) improves roll stability characteristics. These findings demonstrate the proposed system’s capability to balance passenger comfort with energy conservation and safety requirements. Full article

Climate change has driven global awareness of environmental issues, leading to the adoption of clean technologies aimed at reducing Greenhouse Gas (GHG) emissions. An effective method to assess environmental mitigation is the quantification of the Product Carbon Footprint (PCF) in the Life Cycle Assessment (LCA) of production processes. In the oil extraction industry, artificial lift systems use electro submersible pumps (ESPs) that can now incorporate new operating principles based on permanent magnet motors (PMMs) and CanSystem (CS) as an alternative to traditional normal induction motors (NIMs) and can help lower the carbon footprint. This study compares the PCF of ESPs equipped with PMMs and CS versus NIMs, using LCA methodologies in accordance with ISO 14067:2018 for defining the Functional Unit (FU) and ISO 14064-1:2019 to calculate the GHG inventory and the amount of CO₂ equivalent per year. The analysis spans five key stages and 14 related activities. For ESPs with NIMs, this study calculated 999.9 kg of raw materials, 1491.66 kW/h for manufacturing and storage, and 5.77 × 10⁴ kW/h for use. In contrast, ESPs with PMMs and CS required 656 kg of raw materials and consumed 4.44 × 10⁴ kW/h during use, resulting in an 23% reduction in energy consumption. This contributed to an 21.9% decrease in the PCF. The findings suggest that PMMs and CS offer a sustainable solution for reducing GHG emissions in oil extraction processes globally. Full article