Fabrication of Zn_xCd_1–xSe Nanocrystal-Sensitized TiO₂ Nanotube Arrays and Their Photoelectrochemical Properties

Abstract

Zn x Cd 1−x Se (0 ≤ x ≤ 1) nanocrystals were pulse electrodeposited onto the surface of anatase TiO 2 nanotube arrays for the first time. The pulse-electrodeposition duty cycle plays a determinative role during the nuclei formation and growth process of the Zn x Cd 1−x Se nanocrystals. The composite Zn x Cd 1−x Se/TiO 2 nanotube arrays exhibit high absorption in the visible light region due to the narrow band gap of Zn x Cd 1−x Se and demonstrate a sensitive photoelectrochemical response under visible light illumination with an optimal response achieved for Zn 0.8 Cd 0.2 Se/TiO 2 electrodes. In photoelectrochemical testing, 9-anthracene carboxylic acid acts as a hole donor resulting in a decrease of the measured photocurrent response. In contrast, 2-anthramine acts as an electron donor, resulting in an increase of the photocurrent response.

One-step electrodeposition of CdSe on nanoparticulate titania films and their use as sensitized photoanodes for photoelectrochemical hydrogen production

“…Films consist of a bottom compact layer about 350 nm thick and a top porous structure made of P25 nanoparticles, about 10 m thick. CdSe films were deposited on the nc-TiO 2 /FTO electrodes by electrodeposition and by modifying published procedures [8,10,11]. Aqueous precursor solution contained CdSO 4 ·8/3H 2 O and SeO 2 .…”

“…Selenium oxide to cadmium salt molar ratio was always 1:100. Excess of cadmium in the precursor solution is a common practice followed by other researchers [8,10,11] and it is related to the reactivity of the interacting species with nanocrystalline titania surface. The concentration of cadmium sulfate ranged between 0.05 and 0.5 mol L −1 with highest concentration considered the optimal choice.…”

“…Furthermore, due to its electrical nature, electrodeposition can be more accurately controlled than chemical bath-based deposition. For this reason, in the present work we have developed a method of one-step electrochemical deposition of CdSe [8] under ambient conditions, in an easy to prepare and low cost aqueous electrolyte, thus leading to an easy means of sensitizing nc-TiO 2 photoanodes. Easy electrochemical deposition may provide the means for upscaling.…”

Self-organized Anodic TiO2 Nanotubes: Functionalities and Applications Due to a Secondary Material

“…Electrodeposition of nanocrystals of selenides (ZnCdSe) on openings of anodic TiO 2 nanotubes was demonstrated by Kang and coworkers [51]. They showed that the electrodeposition is plausible technique for deposition of selenides onto nanotube arrays, as shown in Fig.…”

Electrodeposition of Zn(O,S) (zinc oxysulfide) thin films: Exploiting its thermodynamic and kinetic processes with incorporation of tartaric acid

“…To mitigate the drawbacks of these methods, electrodeposition would be a potentially alternate approach for low-cost, high-quality fabrication. Electrodeposition is a powerful technique to deposit metal as well as chalcogenide [35,36] . It demands no vacuum condition so both energy consumption and procedure complexity can be reduced compared to vacuum methods, while more precise control than CBD could be achieved by carefully tuning the deposition potential and current.…”