Ultrastable nitrogen-doped carbon encapsulating molybdenum phosphide nanoparticles as highly efficient...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Renewable energy systems require efficient and cost-effective hydrogen evolution reaction (HER) catalysts.
• Developing catalysts that operate effectively across all pH conditions remains a significant challenge.

Purpose of the Study:

• To synthesize nitrogen-doped carbon encapsulating molybdenum phosphide nanoparticles (MoP NPs@NC) using a facile one-step method.
• To evaluate the HER catalytic activities and stability of the synthesized MoP NPs@NC across various pH conditions.

Main Methods:

• A one-step synthesis approach using ammonium molybdate, ammonium dihydrogen phosphate, and melamine as precursors.
• Characterization of MoP NPs@NC for structural advantages like ultrasmall nanoparticle size, large surface area, and fast charge transfer.
• Electrochemical testing of HER performance in acidic, neutral, and basic electrolytes.

Main Results:

• MoP NPs@NC demonstrated excellent HER catalytic activities with low overpotentials (115 mV in H2SO4, 136 mV in PBS, 80 mV in KOH) at 10 mA cm-2.
• Achieved unprecedented high catalytic activities for molybdenum phosphide-based catalysts under neutral and basic conditions.
• The N-doped carbon encapsulation provided remarkable stability, showing nearly unfading performance after 100 hours in acidic conditions.

Conclusions:

• The developed MoP NPs@NC is a highly active and stable electrocatalyst for HER across all pH values.
• This work offers a new strategy for designing and fabricating low-cost metal phosphide electrocatalysts encapsulated by N-doped carbon.
• The findings contribute to advancing catalysts for future renewable energy applications.