Ceria deposited titania nanotubes for high performance supercapacitors

The present paper reports the application of a rare earth metal oxide - titania nano tube (TNT) composite for supercapacitor applications. Highly ordered arrays of single walled titaniananotubes of length approximately 4 mu m were synthesised on titanium metal foil via a modified single step electrochemical anodization method. Nanostructured ceria is deposited on as prepared TNT by simply impregnating in cerous nitrate solution, followed by heat treatment. The characterizations were done by XRD and FE-SEM analysis. Supercapacitive performance is monitored using techniques such as CV, GCD and EIS. The pristine TNT itself shows promising supercapacitive performance (specific capacitance values similar to 6.82 mF/cm(2)), which is enhanced significantly by coating psuedocapacitive ceria. Among different ceria deposited samples, 0.075 Ce showed the best results with specific capacitance values similar to 55.28 mF/cm(2) at scan rate 5 mV/s, owing to its open porous nanotubular morphology (optimal tube diameter around 20 nm) facilitating smooth charge transport and exposure of enormous amount of active material to the electrolyte, marking an enhancement of about 710% as compared to pristine TNT supercapacitors.