Nanocomposite of multilayer fullerenes with transition metal oxide nanoparticles and a process for the preparation thereof

Abstract

Disclosed herein is a simple, cheaper and green approach for low temperature synthesis of functionalized multilayer fullerene from the pure ghee (clarified butter) to get activated multishell graphitized non-porous fullerene in the form of nano-onions (CNOs), for fabricating high performance exohedral type of super capacitors by incorporating suitable transition metal oxide. Further the invention relates to an exohedral type supercapacitor composite, comprising non-porous CNOs and transition metal oxide nanoparticles with enhanced specific capacitance in 0.5 M H 2 SO 4 .

What is claimed is: 
     
         1 . A supercapacitor nanocomposite comprising non-porous multilayer fullerenes and transition metal oxide nanoparticles with enhanced specific capacitance in the range of 216-1207 F/g at a scan rate in the range of 100-1 mV/s in H 2 SO 4 . 
     
     
         2 . A supercapacitor nanocomposite as claimed in  claim 1 , wherein surface area of non-porous multilayer fullerenes is 486 m 2 /g. 
     
     
         3 . A supercapacitor nanocomposite as claimed in  claim 1 , wherein 0.5 H 2 SO 4  is used. 
     
     
         4 . A supercapacitor nanocomposite as claimed in  claim 1 , wherein non-porous multilayer fullerenes are carbon nano-onions (CNOs). 
     
     
         5 . A supercapacitor nanocomposite as claimed in  claim 1 , wherein the transition metal oxide is MnO 2 . 
     
     
         6 . A supercapacitor nanocomposite as claimed in  claim 1 , wherein diameter of metal in the nano-composites exhibit 10 nm. 
     
     
         7 . A process for preparation of supercapacitor nanocomposite as claimed in  claim 1 , wherein the said process comprises the steps:
 i. collecting thermal black carbon on a glass or ceramic plate directly from the flame of burning ghee;   ii. annealing the thermal black carbon as obtained in step (i) at the temperature 800° C. under an inert atmosphere to get activated multilayer fullerene in nano-onions forms (CNOs);   iii. dispersing activated multilayer fullerene in nano-onions forms (CNOs) obtained in step (ii) in water then adding KMnO 4  followed by sonication;   iv. subjecting the mixture obtained from step (iii) to hydrothermal reaction in microwave oven at the radiation ranging between 200 Wat the temperature 130° C. for a period of 15 min;   v. cooling the mixture obtained in step (iv) followed by separating the composite by vacuum filter to get nanocomposites ;   vi. annealing the nano-composite obtained from step (v) at the temperature 800° C. under an inert gas for a period of 4 h to obtain supercapacitor nanocomposite.   
     
     
         8 . The process as claimed in  claim 7 , optionally incorporating transition metal oxide on thermal carbon black as obtained in step (i) using microwave hydrothermal reaction to obtain nanocomposite and subsequently annealing the obtained composite at 800° C. under an inert atmosphere to get an activated multilayer non-porous, transition metal oxide nanocomposite of CNOs.