P Doped MoO_3-x Nanosheets as Efficient and Stable Electrocatalysts for Hydrogen Evolution

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient electrocatalysts for hydrogen evolution reaction (HER) is crucial for clean energy technologies.
• Molybdenum trioxide (MoO3) based materials are explored for catalytic applications, but often require modifications to enhance their activity.
• Oxygen vacancies and doping are known strategies to improve the electronic and catalytic properties of metal oxides.

Purpose of the Study:

• To fabricate a novel P-doped MoO3-x nanocomposite material with abundant oxygen vacancies.
• To investigate the electrocatalytic activity and stability of the synthesized material for the hydrogen evolution reaction (HER).
• To elucidate the synergistic effects of phosphorus doping and oxygen vacancies on the HER performance.

Main Methods:

• A two-step intercalation method was employed for the synthesis of P-doped MoO3-x nanocomposite.
• Electrochemical characterization techniques were used to evaluate HER performance, including overpotential and electron transfer kinetics.
• Catalytic stability was assessed in electrolytes of varying pH (0.5 M H2SO4, 0.5 M Na2SO4, and 0.1 M NaOH).

Main Results:

• The P-doped MoO3-x nanocomposite exhibited superior HER activity, achieving an overpotential of 166 mV at a current density of 10 mA cm-2 in 0.5 M H2SO4.
• The material demonstrated fast electron transfer, indicating efficient charge transport for catalysis.
• Excellent catalytic stability was observed across a wide pH range, including strong acid, neutral, and strong base solutions.

Conclusions:

• The P-doped MoO3-x nanocomposite with rich oxygen vacancies is a highly active and stable electrocatalyst for HER.
• The synergistic effect between P doping and oxygen vacancies significantly enhances catalytic performance.
• This material holds promise for efficient hydrogen production through water splitting.