The electrochemical conversion of carbon dioxide (CO2) represents a promising strategy for reducing greenhouse gas emissions and facilitating sustainable chemical production. Here, we present a rationally engineered copper foam electrode integrated with a multifunctional nanohybrid comprising copper oxide (Cu2O), bismuth sulfide (Bi2S3), and sulfur-doped graphene (SGr-Bi2S3). The Cu/Cu2O-SGr-Bi2S3 composite leverages synergistic electronic and catalytic interfaces, resulting in outstanding electrocatalytic performance for CO2 reduction. Comprehensive physicochemical and electrochemical analyses, including cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy, demonstrate that the hybrid electrodes deliver significantly higher cathodic current densities and exhibit markedly reduced charge transfer resistance under CO2-saturated conditions compared to unmodified copper counterparts. The nanoscale distribution of Bi2S3 effectively increases the density of active catalytic sites, while strong electronic coupling at the heterointerfaces suppresses the competing hydrogen evolution reaction. As a result, the Cu/Cu2O-SGr-Bi2S3 nanohybrids achieve superior activity, enhanced current densities, and excellent operational stability, outperforming conventional copper-based electrodes. These results position the Cu/Cu2O-SGr-Bi2S3 nanohybrids as highly efficient, scalable, and economically viable electrocatalysts for next-generation CO2 reduction technologies.
This study presents an integrated experimental and theoretical investigation into the corrosion inhibition of carbon steel in 1.0 M HCl using Piper nigrum seed extract and its poly(lactic-co-glycolic acid) or PLGA-based nanoformulation. Electrochemical analyses revealed that the nanoencapsulated system markedly suppressed anodic dissolution and cathodic hydrogen evolution, achieving inhibition efficiencies above 90% across a wide concentration range. Surface characterization via SEM, TEM, EDS, and FTIR confirmed the formation of a compact, adherent protective layer, with distinct shifts in C=O, C-O, and aromatic vibrational bands evidencing chemisorption of phytochemicals and polymer-assisted encapsulation. Complementary density functional theory (DFT) calculations and molecular dynamics (MD) simulations demonstrated strong electron donation, favorable adsorption geometry, and stable inhibitor-metal interactions with adsorption energies exceeding-170 kJ/mol. The combined findings establish a robust mechanistic basis for the inhibitor's performance, highlighting the synergistic benefits of phytochemical constituents and nanocarrier encapsulation. The results not only underscore the promise of Piper nigrum as an eco-friendly corrosion inhibitor but also demonstrate how nanoengineering strategies can advance green chemistry approaches to industrial corrosion mitigation.
In redox systems that obey the Nernst equation, where the surface and bulk concentrations remain in equilibrium during the potential sweep, the Randles-Sevcik equation is seen as a standard tool in both fundamental and applied linear scan voltammetry. As the Randles-Sevcik equation is seen as a key theoretical framework for interpreting voltammetric behavior in electrochemically reversible and diffusion-controlled redox systems considered under conditions of linear scan voltammetry, this foundational relationship becomes inapplicable when extended to pulse voltammetric techniques. Pulse voltammetric techniques differ fundamentally from linear scan voltammetric methods in both potential modulation and in current measurement protocols. The form of applied bias in pulse voltammetric techniques leads to conditions in which each applied pulse disrupts the diffusion profile of redox species of interest. Repeated disruption and compression of diffusion profiles in pulse voltammetric techniques introduce significant complexity into the current-potential behavior of redox species, thereby precluding the direct application of the Randles-Sevcik formalism. This study presents some basic theoretical insights into the limitations of applying Randles-Sevcik-type equations to square-wave voltammetry. In addition, a unifying parameter has been identified that governs the peak current response in square-wave voltammetry, which integrates the effects of potential step, frequency, square-wave amplitude, and temperature. At constant magnitude of the diffusion coefficient, this critical parameter is defined as chi = constant . (F/RT).[E-sw/(dE.f)](1/2) and it is seen as a foundation for developing more comprehensive models and analytical expressions describing peak current dependencies under square-wave voltammetric conditions.
this study, a novel voltammetric sensor for the detection of bisphenol A (BPA) was developed using a reduced graphene oxide (rGO) electrode incorporated with a TiO2-NiO-MnO2 nanocomposite (rGO/TNM). The TNM nanocomposite was synthesized via a hydrothermal method, and its integration with rGO improved the sensor's electrochemical performance by enhancing conductivity, surface area, and active sites. Characterization of the TNM nanocomposite using X-ray diffraction (XRD) confirmed the formation of distinct anatase TiO2, gamma-MnO2, and NiO phases, each contributing to the synergistic enhancement of electrocatalytic properties. Fourier-transform infrared (FTIR) spectroscopy indicated the presence of characteristic metal-oxygen bonds, validating the successful formation of the TNM nanocomposite. Scanning electron microscopy (SEM) revealed a highly uniform and porous morphology with well-dispersed nanoparticles, ideal for maximizing electron transfer. Elemental analysis through energy-dispersive X-ray (EDX) spectroscopy further confirmed the purity and composition of the nanocomposite. Under optimal conditions, the linear range of the rGO/TNM electrode by CV measurement was from 0.1 mu g.L-(1 )to 1.0 mu g.L-1, with a sensitivity and limit of detection (LOD) at 0.01094 mu g.L-1. These results make the developed sensor a promising candidate for environmental monitoring of BPA and highlight the potential of nanocomposite-modified electrodes in advancing electrochemical sensor technology.
A novel bifunctional electrocatalyst, bimetallic Ni/Co phosphide-nitride (BMNi/Co-NP), has been developed for efficient water splitting, targeting both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). This electrocatalyst was synthesized via low-temperature phosphidation of a porous Ni-rich cobalt-containing metal-organic framework (MOF). Characterization techniques, including XRD, FTIR, BET, and SEM, confirm the successful synthesis and structural integrity of the catalyst. The proposed electrocatalyst exhibits remarkable electrocatalytic performance with an overpotential of 270 mV for HER and 440 mV for OER at a current density of 10 mA cm-2. The BMNi/Co-NP not only does it exhibits high catalytic activity, but it also demonstrates excellent stability, making it a promising candidate for large-scale clean energy applications. This research highlights the potential of MOF-derived materials in creating cost-effective, efficient electrocatalysts for sustainable hydrogen production.
