Mesoporous Carbon Thin Films as Model Material for Electrochemical Applications
Ordered mesoporous carbon thin films with nanoscaled pore diameters generally represent a promising model system for systematic studies on the impact of porosity on macroscopic properties, e.g., in electrocatalysts and batteries. For such electrochemical applications, however, a metallic substrate is required to ensure a facile electric transport. Therefore, we established a synthesis of mesoporous carbon thin films on titanium plates with well-ordered 70 nm mesopores via soft templating of resol resins with PEO-b-PHA copolymers as structure-directing, micelle-forming agent. Surprisingly, regular carbonization in pure argon suffers from a metal substrate corrosion not yet observed in literature. This corrosion phenomenon is investigated in-depth in our group, and it is identified that adding carbon monoxide to the carbonization atmosphere successfully suppresses substrate corrosion without changing composition or pore structure of the final non-graphitic carbon. The model electrodes are tested for their suitability as electrocatalyst support: The electric transport through and along the thin film is investigated by impedance and Hall measurements and contrasted to the electrocatalyst material IrO2. Accessibility of the pore system and electrochemical stability under acidic water-splitting conditions are studied by SIMS and cyclovoltammetry, respectively. The mesoporous carbon thin films reveal a conductivity as high as for IrO2, high stability, and (tunable) pore accessibility, rendering them a promising model system for several applications like electrocatalysis and sodium-ion batteries.
Publication: L. Q. Wagner, J. Schober, P. Dippell, C. Glatthaar, S. Mekhilef, D. Schäfer, H. Hergert, M. Rohnke, M. T. Elm, B. M. Smarsly, Adv. Funct. Mater.2025, e21031. DOI: 10.1002/adfm.202521031.
