title: Preparation and characterization of palladium nano-crystallite decorated TiO₂ nano-tubes photoelectrode and its enhanced photocatalytic efficiency for degradation of diclofenac.
abstract: TiO2 has been considered as a versatile candidate for the photoelectrochemical (PECH) application. In this study, Pd nano-crystallite decorated TiO₂ nano-tubes (Pd/TNTs) photoelectrode was prepared through electrochemical deposition. The resulting Pd/TNTs samples were characterized by SEM, XRD, DRS and XPS. It was found that the decorated Pd nano-crystallite existed in the form of Pd(0) with an average diameter of 30 nm, and could improve the light absorption in visible region. In addition, PECH properties of Pd/TNTs photoanode were investigated through transient open circuit potential, photocurrent response, electro-chemical impedance spectroscopy (EIS) and Mott-Schottky analysis. Moreover, the generation rate of hydroxyl radicals (•OH) was detected by a photoluminescence (PL) spectra using terephthalic acid (TA) as a probe molecule. Results showed that Pd/TNTs photoelectrode exhibited high transient photoinduced current of 0.094 mA cm(-2), open circuit photovoltage of -0.339 mV cm(-2) and effective photoelectrocatalytic (PEC) efficiency of 67.7% (0.4V vs. SCE) for the degradation of diclofenac (DCF). The high PC and PEC efficiency could mainly be attributed to the decoration of Pd nano-crystallite which could provide pathway for the transfer of photoinduced charge carriers. Furthermore, the contribution of series of active species was applied to clarify the enhanced PC mechanism.
authors.affiliation: State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), Harbin Institute of Technology, Huanghe Road 73, Nangang District, Harbin 150090, PR China.
authors.forename: Xiuwen
authors.initials: X
authors.lastname: Cheng
authors.affiliation: State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), Harbin Institute of Technology, Huanghe Road 73, Nangang District, Harbin 150090, PR China. Electronic address: hlliu2002@163.com.
authors.forename: Huiling
authors.initials: H
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), Harbin Institute of Technology, Huanghe Road 73, Nangang District, Harbin 150090, PR China.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), Harbin Institute of Technology, Huanghe Road 73, Nangang District, Harbin 150090, PR China.
authors.forename: Junjing
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), Harbin Institute of Technology, Huanghe Road 73, Nangang District, Harbin 150090, PR China.
authors.forename: Pu
authors.initials: P
authors.lastname: Wang
mesh_terms: D002384:Catalysis; D004008:Diclofenac / Q000737:chemistry*; D004566:Electrodes; D043942:Nanotubes / Q000737:chemistry* / Q000528:radiation effects; D010165:Palladium / Q000737:chemistry*; D010782:Photolysis; D014025:Titanium / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D004008:Diclofenac; C009495:titanium dioxide; D010165:Palladium; D014025:Titanium