Aerophobic Nanoscaffold‐Catalysts for Process‐Intensified Hydrogen Production in a Membraneless µ‐Fluidic Electrolyzer

ABSTRACT

NiFe‐LDH catalyst has been coated on NF using a simple room‐temperature electrodeposition method. Subsequently, a network of MWCNTs are dispersed on the surface of NiFe‐LDH to form an “aerophobic/hydrophillic” hybrid electrode NiFe‐LDH@CNT/NF, suitable for rapid synthesis as well as ejection of hydrogen bubbles inside a membraneless microfluidic electrolyzer. Electron microscopy and spectroscopic analysis demonstrate that interconnected nanosheets of NiFe‐LDH form uniformly over the entire substrate and that CNTs are uniformly distributed. The hybrid structure aids in improving the catalytic performance of the NiFe‐LDH/NF system, also enhancing electrical conductivity for better ion transport, hydrophilicity for better electrode–electrolyte contact and aerophobicity for faster hydrogen bubble ejection. These enhance the rate of detachment of hydrogen bubbles from the electrode. This combination ultimately yields improved kinetic behavior associated with ionic transport, faster evolution and increased hydrogen productivity. Detailed CV, XPS, and XRD analyses confirm the long‐term stability of Ni ²⁺ /Fe ³⁺ of such electrodes during hydrogen synthesis. Further, the electrolytic measurements on the electrodes indicate low overpotential, low charge transfer resistance (∼3 Ω), high current density and high Faradaic efficiency (∼90.02%). The proposed electrodes also attain much higher hydrogen production rate of ∼20 mmol h ⁻¹ cm ⁻² , demonstrating excellent kinetic behavior while showing extended durability.