Coordination Polymers—Zn(DAB) and Cd(DAB)

News: Indian scientists developed coordination polymers Zn(DAB) and Cd(DAB) showing strong performance in energy storage and green hydrogen production.

About Coordination Polymers – Zn(DAB) and Cd(DAB)

• Zn(DAB) and Cd(DAB) are coordination polymers made of zinc (Zn2+) or cadmium (Cd2+) metal ions and organic molecules of 3,3′-diaminobenzidine (DAB) naturally assemble to form layered frameworks with strong structures.
• Developed by: These materials were developed by scientists from the Centre for Nano and Soft Matter Sciences (CeNS) under the Department of Science and Technology, in collaboration with CHRIST (Deemed to be University), Bengaluru.
• Synthesis: They are synthesized using a simple room-temperature process without complex equipment or high temperature, which allows large-scale production.
• Structure: The materials consist of zinc (Zn²⁺) or cadmium (Cd²⁺) ions combined with organic DAB molecules to form strong layered frameworks.
• Characteristics
  • Energy storage (Supercapacitors): Both materials show strong energy storage performance when tested in a standard three-electrode setup, which is used to evaluate materials individually.
    • Zn(DAB): Achieved 4 farads per gram (F/g).
    • Cd(DAB): Achieved 6 farads per gram (F/g).
  • Performance in practical devices: Under device-like conditions using asymmetric supercapacitors, Zn(DAB) reached 785.3 farads per gram (F/g), while Cd(DAB) reached 428.5 farads per gram (F/g).
  • Green hydrogen production: Both materials act as electro-catalysts for electro-catalytic water splitting, which is used to produce hydrogen fuel.
  • Low energy requirement (Overpotential): They require low energy input, with 263 millivolts (mV) for Zn(DAB) and 209 millivolts (mV) for Cd(DAB).
  • Durability and stability: Both materials retained a significant amount of their energy capacity after 5000 charge-discharge cycles, showing strong long-term stability.
• Significance: These materials show dual functionality in energy storage and hydrogen production, making them useful for clean and accessible energy solutions.