Microwave Synthesis of SnWO4 Nanoassemblies on DNA Scaffold: A Novel Material for High Performance Supercapacitor and as Catalyst for Butanol Oxidation

摘要

Self-assembled, aggregated SnWO4 nanoassem-blies are formed by the reaction of Sn(II) salt and Na2WO4· 2H2O in the presence of DNA under microwave heating within 6 min. We have emphasized the natural properties of DNA with its ability to scaffold SnWO4 nanoassemblies and examined the role of starting reagents on the particles’ morphology. The diameter of the individual particles is ultrasmall and varies from ～1-2.5 nm. The potentiality of the SnWO4 nanoassemblies has been tested for the first time in two different applications, such as an anode material in electrochemical supercapacitor studies and as a catalyst for the oxidation of butanol to butanoic acid. From the supercapacitor study, it was observed that SnWO4 nanoassemblies with different sizes showed different specific capacitance (C_s) values and the highest Cs value was observed for SnWO4 nanoassemblies having small size of the individual particles. The highest C_s value of 242 F g~(-1) was observed at a scan rate of 5 mV s~(-1) for small size SnWO4 nanoassemblies. The capacitor shows an excellent long cycle life along with 85% retention of Cs value even after 4000 consecutive times of cycling at a current density of 10 mA cm~(-2). From the catalysis studies, it was observed that SnWO4 nanoassemblies acted as a potential catalyst for the oxidation of butanol to butanoic acid using eco-friendly hydrogen peroxide as an oxidant with 100% product selectivity. Other than in catalysis and supercapacitors, in the future, the material can further be used in sensors, visible light photocatalysis and energy related applications.