Phosphorus doped nickel selenide for full device water splitting

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Electrochemical water splitting is crucial for renewable energy but limited by catalyst performance.
• Developing highly active and stable electrocatalysts is essential for device efficiency.

Purpose of the Study:

• To synthesize and characterize phosphorus-doped nickel selenide (P-NiSe2) as an efficient electrocatalyst for water splitting.
• To investigate the impact of phosphorus doping on the electrochemical properties of NiSe2.

Main Methods:

• One-step synthesis of P-NiSe2 via selenylation of nickel foam using NaH2PO2 and Se powder.
• Electrochemical characterization including overpotential measurements for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER).
• Testing P-NiSe2 as both anode and cathode in an alkaline water electrolyzer.

Main Results:

• P-NiSe2 exhibits superior electrochemical activity with a current density of 10 mA cm-2 at 270 mV (OER) and 71 mV (HER) overpotential.
• Phosphorus doping enhances Ni active sites' valence state for OER and optimizes d-band center for HER kinetics.
• An alkaline water electrolyzer using P-NiSe2 achieved 10 mA cm-2 at 1.58 V.

Conclusions:

• Phosphorus doping significantly improves the electrocatalytic performance of NiSe2 for water splitting.
• The facile synthesis protocol and enhanced properties make P-NiSe2 a promising candidate for practical water electrolysis applications.