DNA Aided Formation of Aggregated Nb₂O₅ Nanoassemblies as Anode Material for Dye Sensitized Solar Cell (DSSC) and Supercapacitor Applications

Herein, we report the synthesis of niobium pentoxide nanoassemblies in ambient conditions by dissolving niobium pentachloride in aqueous DNA solution and stirring for 30 min with intermittent microwave heating for about 3 min. In the chain-like assemblies thus formed, one may easily alter the specific average diameter of individual particles by varying the concentration ratio of starting precursor solution. The individual size of the Nb 2 O 5 particles varied to 7 ± 2 nm ranges, whereas the chain length varied to 1 ± 0.3 μm ranges. The synthesized DNA aided Nb 2 O 5 nanoassemblies had been utilized in two different potential energy related applications, such as an anode material in a dye sensitized solar cell (DSSC) and in electrochemical supercapacitor studies. From electrochemical studies on Nb 2 O 5 nanoassemblies as an anode for supercapacitor applications, a key finding was that these nanoassemblies exhibited varying specific capacitance ( C S ) values for two different morphologies. The small sized chain like nanoassemblies had shown greater specific capacitance than the other one with larger average chain diameter. We had observed C S values as high as 42.6 F g –1 at a scan rate of 5 mV s –1 for Nb 2 O 5 nanoassemblies of smaller sizes. Moreover, the cycling study revealed that Nb 2 O 5 nanoassemblies possessed a relatively good cycle life with 60% retention of C S value even after 4000 cycles. The present work will certainly encourage exploring a new opportunity for the synthesis of other metal or mixed metal based oxide materials at low time scales in room temperature using a biomolecular scaffold for further catalysis based applications for various reactions and other energy storage applications such as Li-ion batteries.