Noncalcined Pillared Cu _1-M Co _M Bimetallic–Organic Framework as Bifunctional Electrocatalyst for Urea-Assisted Hydrogen Production in Seawater

The urea oxidation reaction (UOR) provides an energy-efficient mechanism for H₂ generation from urea-rich wastewater while also supporting environmental remediation efforts. The current research focused on the synthesis of bimetallic Cu_1-MCo_M-MOFs (M= 0, 0.3, 0.7, and 1) electrocatalysts, employing 4,4-oxybis(benzoic acid) (OBA) and N,N-bis(4-pyridylformamide)-1,4-benzenediamine (BPFB) as linkers through the single-step hydrothermal approach. The resulting compounds were subsequently used as efficient bifunctional catalysts for urea-driven water electrolysis. Meanwhile, the bimetallic Cu_0.5Co_0.5-MOFs demonstrated superior electrocatalytic performance due to their extremely low onset potential (1.72 V for OER and 1.30 V vs RHE for UOR), a Tafel slope of 128 mV dec^-1, and a high turnover frequency (TOF) equal to 0.068 s^-1, along with significantly high stability. Active site exposure was enhanced through the synergistic interaction between cobalt and copper, facilitating effective mass transport and improving the electrical conductivity. These combined effects boost electrocatalytic performance and promote urea-driven H₂ generation. The study demonstrates that incorporating urea into the electrolyte system may reduce the reaction potential, facilitating more efficient H₂ generation through water splitting.