TiO2 Nanotube Array Photoanode Research Articles

Impedence Characterization of the Donor Materials Effect on Photoelectrocatalytic Hydrogen Production by Water Splitting Using TiO<sub>2</sub> Nanotube Arrays Photoanode

Anatase TiO2nanotube arrays with about 50nm pore diameter were prepared by anodic oxidation. The effect of the donor materials (sodium hydroxide, methanol and ethylene glycol) on electrochemistry impedance spectroscopy (EIS) and the photocurrent responses of TiO2nanotube arrays photoanode in the photoelectrochemical cell for splitting water hydrogen production were investigated. The results indicate that all the donor materials enhance the photocurrent responses and reduce the internal reaction resistances of the TiO2nanotube arrays photoanode. The effect of adding organic donor compounds in the anolyte on charge transfer and photocurrent is superior to the inorganic donor compounds and in turn reduces from the ethylene glycol, methanol to sodium hydroxide. Additionally, it should be highlighted that +0.3V vs. open circuit potential of applied potential on the electrode promotes a suitable charge transfer at semiconductor/electrolyte interface. The flat band potentials of TiO2nanotube arrays photoanode move to negative direction with donor materials adding in the anolyte which indicates beneficial photoelectrocatalytic hydrogen production by water splitting.

Sonication-assisted sequential chemical bath deposition of CdS nanoparticles into TiO2 nanotube arrays for application in solar cells

CdS nanoparticles sensitized TiO2 nanotube arrays photoanode for semiconductors sensitized solar cells (SSSCs) were prepared by sonication-assisted sequential chemical bath deposition (SSCBD) approach and labeled as S-CdS/TNTAs. The S-CdS/TNTAs solar cell was assembled into a typical sandwich structure with backside illumination. Short-circuit current density (Jsc), open circuit potential (Voc), fill factor (FF) and power conversion efficiency (PCE) of the cells under AM 1.5 irradiation were about 4.16mAcm−2, 446mV, 43.9% and 0.814%, respectively. Compared with classical sequential chemical bath deposition (SCBD), SSCBD process could effectively prevent CdS nanoparticles aggregating at the top surface of TNTAs and resulted in an increase of PCE by 65.8%. Increased performance of S-CdS/TNTAs solar cell may be attributed to the more efficient charge-transfer process and the lower charge recombination, as evidenced from FESEM and electrochemical impedance spectroscopy (EIS).