Sr-induced Fermi Engineering of β-FeOOH for Multifunctional Catalysis.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing multifunctional electrocatalysts for hydrogen production from various sources like water, urea, and urine is crucial.
• Achieving efficient catalysis requires precise Fermi-level engineering to optimize electron transfer between metal orbitals.

Purpose of the Study:

• To design and introduce a novel multifunctional electrocatalyst (pt-NFS) for hydrogen production.
• To investigate the role of strontium (Sr) in phase transformation and Fermi-level modulation of the catalyst.
• To evaluate the catalyst's performance in hydrogen evolution reaction (HER), oxygen evolution reaction (OER), urea oxidation reaction (UOR), and human urine oxidation.

Main Methods:

• Synthesis of a Sr-induced phase transformed β-FeOOH/α-Ni(OH)₂ catalyst anchored on Ni-foam (pt-NFS).
• Characterization of catalyst properties, including Fermi-level modulation and electron transfer mechanisms.
• Electrochemical testing for HER, OER, UOR, and urine oxidation at a benchmark current density of 10 mA cm⁻².
• Durability testing over 25 hours.

Main Results:

• The pt-NFS catalyst exhibits efficient hydrogen production from water, urea, and urine.
• Strontium doping successfully modulates the Fermi level and facilitates π-donation for enhanced electron transfer.
• The catalyst demonstrates low overpotentials for HER (133 mV), OER (193 mV), UOR (≈1.352 V), and urine oxidation (≈1.375 V).
• The catalyst shows excellent stability over 25 hours of operation.

Conclusions:

• The developed pt-NFS catalyst offers a promising solution for multifunctional hydrogen production.
• Fermi-engineering via d-band modulation is an effective strategy for designing advanced electrocatalysts.
• This work opens new avenues for creating efficient electrocatalysts for energy conversion applications.