Crystalline/amorphous heterostructure offering highly efficient overall water splitting and urea electrolysis

摘要

Hydrogen is an efficient energy carrier alternative to the non-renewable traditional fossil fuels energy. Water electrolysis is a promising technique used for clean hydrogen generation. Usually, the oxygen-evolution reaction (OER) and urea-oxidation reaction (UOR) processes play a vital role in hydrogen production and pollution control. Herein, we report the fabrication of a three-dimensional (3D) crystalline/amorphous heterostructure NiTe/Ni-S electrocatalyst grown on nickel-foam (NF) via facile two steps (i.e., hydrothermal and electrodeposition) strategy. The synthesized NiTe/Ni-S catalyst exhibits an excellent performance toward the OER with a small overpotential of 216 mV to achieve 10 mA cm(-2) current density in 1.0 M KOH. Further, it only requires a small voltage of 1.315 V (vs. the reversible-hydrogen-electrode (RHE)) to drive 10 mA cm(-2) current density for UOR in 1 M KOH with 0.33 M urea, and reveals excellent long-term catalytic stability. Moreover, the overall water splitting experiments were conducted in 1 M KOH electrolyte with the NiTe/Ni-S catalyst as an anode and Pt/C as a cathode. It is obvious that only 1.500 and 1.527 V is required to achieve a current densities of 10 mA cm(-2) and 20 mA cm(-2), respectively.

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