A new class of amorphous/crystalline hybrid iron disulfide (FeS₂) electrocatalysts has been developed through a self-reconstruction mechanism during the oxygen evolution reaction (OER). This catalyst was synthesized by sulfurizing Fe₂O₃ nanocubes at 450 °C under inert conditions, resulting in hollow spherical nanostructures with a core–shell-like architecture. The initial material exhibits well-defined crystallinity, as confirmed by XRD and HRTEM, with clear lattice fringes corresponding to the (110) plane of FeS₂. However, upon exposure to alkaline OER conditions, the surface undergoes profound transformation. Post-reaction characterization reveals that the original crystalline FeS₂ surface is replaced by an amorphous hybrid layer composed of sulfides and hydrated oxides/hydroxides, forming a distinct interface critical for catalytic activity. A high density of structural defects, including sulfur vacancies and edge sites, is observed within this amorphous region, which facilitates adsorption and activation of water molecules. XPS analysis shows a significant shift in the Fe 2p spectrum, indicating oxidation of Fe²⁺ to Fe³⁺, while S 2p peaks reveal the presence of sulfate species due to sulfur leaching and oxidation. Mössbauer spectroscopy further confirms the formation of superparamagnetic Fe(OH)ₓ phases and residual Fe₂O₃, consistent with surface reconstruction. These dynamic changes enhance electron transfer and expose abundant active sites. The resulting catalyst delivers a record-low overpotential of 189.5 mV (IR-corrected) to achieve 10 mA cm⁻² in 1.0 M KOH, outperforming commercial RuO₂. In a two-electrode configuration using Pt/C as the cathode, the system achieves overall water splitting at only 1.43 V at 10 mA cm⁻², demonstrating superior efficiency. Stability tests confirm minimal degradation after 18,000 seconds of operation, and Tafel analysis yields a low slope of 71 mV dec⁻¹, reflecting fast reaction kinetics.SULT1A1 Antibody References The synergy between the crystalline core and amorphous surface enables efficient charge transfer across heterogeneous interfaces, while defect-rich regions promote optimal intermediate adsorption.Integrin α5 Antibody Autophagy This work establishes that surface self-reconstruction is not merely a side effect but a fundamental design principle for next-generation electrocatalysts.PMID:34152611 By leveraging such dynamic transformations, it becomes possible to engineer materials whose true active states emerge only under operational conditions, paving the way for smarter, adaptive catalysts in renewable energy applications.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com