Platinum nanoparticle-decorated carbon nanowall anodes fabricated via top-down approach for abiotic glucose fuel cells

A glucose fuel cell (GFC) was fabricated using abiotic catalysts supported on carbon nanowalls (CNWs) as the anode electrode. The CNWs were immobilized on a 50 nm-thick patterned Pt thin film and selectively grown on the unmasked regions of heat-resistant spin-on-glass (SOG) films. They were vertically aligned and uniformly spaced at approximately 150 nm through radical injection plasma-enhanced chemical vapor deposition (RI-PECVD) at 650 °C. The top and side surfaces of the CNWs, serving as electrically conductive supports, were fully decorated with platinum nanoparticles (PtNPs) averaging 1.8 nm in diameter. This decoration was achieved via supercritical fluid chemical deposition (SFCD) using trimethyl(methylcyclopentadienyl)platinum(IV) [(CH₃C₅H₄)Pt(CH₃)₃] as the precursor at 175 °C under a CO₂ pressure of 10 MPa. After etching the SOG films with buffered hydrogen fluoride (BHF) solution, the PtNP-supported CNWs (PtNP/CNWs) were lifted from the masked regions. This method provides a straightforward approach for GFC fabrication. The GFC, incorporating top-down-fabricated PtNP/CNWs as the anode and a carbon nanotube-based cathode, achieved a maximum power density of 25.3 nW/cm².