Electrochemical properties of novel titania nanostructures

摘要

In this study, the supercapacitive properties of six new TiO2 nanostructures-including nanodishes, three-layer nanosheets, ancient Chinese coins, single-layer nanosheets, hollow nanocubes, and commercial rutile TiO2 are investigated mainly by cyclic voltammetry, chronopotentiometry, and electrochemical impedance spectroscopy. The results show that among them, the TiO2 nanodishes have the highest discharging capacitance at 1792 mFg(-1), which is 6.4 and 1.5 times higher than that of TiO2 single-layer nanosheets and commercial rutile TiO2, respectively. We found that the electrochemical properties of the TiO2 samples are predominated primarily by the high-energy facets exposed, instead of by the Brunauer-Emmett-Teller area. An important and previously unknown finding of our work is that the electrochemical properties of electrode materials can be improved by controlling the high-energy facets.