Redox-Induced Enhancement in Interfacial Capacitance of the Titania Nanotube/Bismuth Oxide Composite Electrode

Abstract

Bismuth oxide (Bi2O3) decorated titania nanotube array (T-NT) composite materials were synthesized by a simple, yet versatile electrodeposition method. The effects of deposition current density and time on morphology evolution of the bismuth oxide phase were analyzed. It was found that an optimum deposition condition in terms of current density and time could be reached to achieve uniform and equiaxed crystal morphology of the deposited oxide phase. The morphology, shape, size distribution, and crystal structure of the bismuth oxide phase were evaluated using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopic techniques. The electrochemical capacitance of the T-NT/Bi2O3 composites was studied by conducting cyclic voltammetry and galvanostatic charge-discharge experiments. These studies indicated that the capacitance behavior of the composite material was dependent on the morphology and distribution of the bismuth oxide phase. The capacitance was greatly enhanced for the composite having equiaxed and uniformly distributed bismuth oxide particles. The maximum interfacial capacitance achieved in this study was approximately 430 mF cm(-2). Galvanostatic charge-discharge experiments conducted on the composite materials suggested stable capacitance behavior together with excellent capacitance retention even after 500 cycles of continuous charge-discharge operation.

Preparation of bismuth-based microrods and their application in electroanalysis

“…agreed with the Bi 4f signals for Bi metal [14], indicating the BiMRs product surely contains the metal bismuth and bismuth oxide.…”

Synthesis, crystal structure and pseudocapacitor electrode properties of γ-Bi2MoO6 nanoplates

“…The observed high peak current in 1 M NaNO 3 and 1 M NaOH electrolyte is due to the partial dissolution of the oxide into BiO 2 − ionic species and the reversible reaction of Bi(III) to Bi metal [38,39]. that the anionic size is played an important role to achieve the high specific capacitance of the electrode.…”

“…The observed redox reactions is attributed to the reversible reaction of bismuth(III) to Bi metal, which indicates pseudocapacitance [38,39]. The redox reactions in bismuth molybdates is similar to bismuth oxide and redox properties of bismuth oxide in hydroxide group containing electrolyte (KOH, NaOH) was well described in various works [38][39][40][41]. The reports pointed out that the reduction of bismuth oxide is due to the partial dissolution of the oxide to BiO 2 − ionic species in hydroxide group containing electrolyte.…”

Continuous-Flow Photocatalytic Degradation of Organics Using Modified TiO2 Nanocomposites

“…In the XRD patterns of the Bi-TNTs composite, bismuth was present in a separate phase of bismuth oxide. The main bismuth peaks were observed at 27.4°, 47.1°, and 56.0° [17,29,30].…”