High-Efficiency Tantalum-Nitride Electrodes for Photoelectrochemical Water Splitting

• Main Authors: Yi-ChiehWang, 王逸杰
• Other Authors: Hsi-sheng Teng
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/27304217336125374186

碩士 === 國立成功大學 === 化學工程學系 === 103 === In the present work, a new method combining anodization and hydrothermal method is used to fabricate a n-type semiconductor cubic tantalum nitride(C-Ta3N5) electrode. From XRD and SEM analysis, which can know that C-Ta3N5 belong to orthorhombic phase, and has larger size of cubic particles with the hierarchical porous structure made up of Ta3N5 nanoparticles. Besides, the Co element doping of cubic tantalum nitride(C-Ta3N5:Co) electrode can significantly increase photocurrent by the built-in p-n junction which helps for charge separation and reduces the charge recombination. Therefore, the performance can be strongly enhanced. Different form general anodization method, the new method can synthesize cubic tantalum nitride(C-Ta3N5) electrode with pores increasing the surface area. However, the cubic particles are quit large leading to bad charge transfer because the whole structure is not compact enough and rare connection between particles. To improve this situation, the tantalum chloride solution is used for post-treatment to increase the connection of particles and make them more compact. During the photoelectrochemical test conducting in three-electrode system under AM 1.5 G simulated sunlight illumination, the photocurrent density of C-Ta3N5:Co can reach 3.6 mA/cm2, which is much higher than bare Ta3N5 electrode at 0.5 V vs. Ag/AgCl in 0.5M KOH solution.