Copper coordination polymer with lattice water molecules and strong electrocatalytic OER activity

Abstract

The versatility of organic ligand and metal coordination geometry produced coordination polymer with intriguing network structure and exciting functional properties. Herein, we have synthesized a copper coordination polymer (Cu-HS) using an amino acid based multidentate ligand and explored its electrocatalytic OER activity in alkaline condition. Single crystal structural studies showed the formation of 1D coordination network structure and inclusion of lattice water. Copper ions in Cu-HS displayed octahedral and square pyramidal coordination geometry. Electrocatalytic OER studies in alkaline medium showed strongly enhanced activity for Cu-HS polymer that required an overpotential of 273 mV to achieve the benchmark current density of 10 mA/cm2. Tafel slope analysis and electrochemical impedance studies suggested faster reaction kinetics at the electrode surface modified using Cu-HS. After catalysis, XPS and FTIR spectra of Cu-HS suggested the conversion to metal oxide during the electrocatalysis.

Keywords

• Copper coordination polymer
• Metal–organic frameworks
• Electrocatalysis
• Water splitting reactions
• Oxygen evolution reaction