Two-dimensional Co/Ni coordination polymers: structure-activity relationship and bifunctional performance for...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Developing efficient and stable electrode materials is crucial for energy storage and conversion technologies.
• Porous coordination polymers offer tunable structures for enhanced electrochemical applications.

Purpose of the Study:

• To synthesize and characterize two-dimensional layered porous coordination polymers (Co-MOCP and Ni-MOCP).
• To evaluate their bifunctional electrocatalytic performance for HER and OER.
• To assess their potential as electrode materials for supercapacitors.

Main Methods:

• Hydrothermal synthesis route for Co-MOCP and Ni-MOCP.
• Electrochemical measurements including cyclic voltammetry and galvanostatic charge-discharge.
• Frontier molecular orbital calculations for electronic structure analysis.

Main Results:

• Co-MOCP demonstrated superior bifunctional electrocatalytic activity (HER/OER) and higher specific capacitance (602 F g⁻¹ at 1 A g⁻¹) compared to Ni-MOCP.
• Co-MOCP exhibited excellent structural stability in alkaline environments and retained 80.1% capacitance after 10,000 cycles.
• Computational analysis revealed that Co-MOCP's narrow band gap and delocalized orbitals facilitate electron transfer, unlike Ni-MOCP.

Conclusions:

• The metal center significantly influences the electrochemical properties and performance of MOCPs.
• Co-MOCP is a promising low-cost, high-performance multifunctional electrode material for energy applications.
• This research provides insights into designing novel coordination polymers for catalysis and energy storage.