Study of metal organic frameworks MOFs based nanocomposite material for supercapacitor application

Abstract

Binder Free Ni and Co-MOFs have been successfully synthesized using an environmentally friendly hydrothermal method with different organic linkers, BTC and BDC with different ratio of metal ions and organic linkers. Highest value of specific capacitance has been obtained for the sample Ni-BTC MOF having ratio of Ni: BTC = 3:1. Bimetallic NiCo-MOFs utilizing the organic linker BTC and BDC with the different concentration of Ni and Co are also synthesized via the hydrothermal method to determine the most suitable material for supercapacitor electrode applications. Highest value of specific capacitance has been obtained for the bimetallic sample NiCo-BTC-MOF having ratio of Ni:Co = 1:1. BET study and electrochemical measurements reveal that bimetallic MOFs contain larger specific area and exhibit the high specific capacitance then the monometallic MOFs. All the electrochemical measurements of prepared samples are performed in 1M KOH alkaline aqueous electrolyte solution. To further enhance the electrochemical performance of bimetallic MOFs, composites of NiCo-BTC MOF and NiCo-BDC MOF with different ratio of rGO are synthesized by chemical method. Out of these samples, highest value of energy density has been obtained for sample NiCoatR-b (NiCo-BTC: rGO =6:1.5) suggesting that electrochemical performance has been enhanced by doping of rGO in bimetallic MOF. newline