Preparation, Characterization, and Photoelectric Properties of an Electrostatically Self-Assembled Film Based on Tungstophosphoric Acid and a Binuclear Ru(II) Complex

Abstract

An electrostatically self-assembled film based on tungstophosphoric acid (PTA) and a binuclear Ru(II) complex RuL was prepared and characterized by UV-vis absorption spectroscopy and cyclic voltammetry. A linear increase in the UV-vis absorbance with the number of deposited layers indicated that the film deposition was uniform and reproducible. The cyclic voltammogram demonstrated that PTA and the binuclear Ru(II) complex assembled in the film were redox active with surface confined characteristics. The photoelectrochemical properties and mechanism of photocurrent generation have also been studied. A five-layer (PTA/RuL)5 film on the ITO was found to exhibit a large cathodic photocurrent density of 5.32 microA/cm2 while irradiated with polychromatic light (730 nm > lambda > 325 nm) at an applied potential of -0.3 V versus saturated calomel electrode. The photocurrent action spectrum was in agreement with metal-to-ligand charge-transfer (MLCT) band of RuL in the absorption spectrum, which indicated that the photocurrent was generated based on MLCT excitation of the RuL in the film. It is noteworthy that the incident monochromatic photon-to-current conversion efficiency was calculated to be 1.1% at a wavelength of 450 nm.

Layer-by-Layer Assembly of Graphene Oxide and a Ru(II) Complex and Significant Photocurrent Generation Properties

“…The photocurrent densities of the Ru(II) film we studied decreased significantly with increasing hydroquinone concentrations (see Figure S7), which is consistent with previous observation that low concentration of electron donating hydroquinone in electrolyte solution would reduce cathodic photocurrent sharply . Moreover, when nitrogen was bubbled into the electrolyte solution for 10 min to remove oxygen, the photocurrent densities were also significantly reduced, as shown in Figure S8, because O 2 also acted as an electron acceptor in solution as it could accept an electron to form a superoxide anion and enhanced the cathodic photocurrents in similar photoelectrochemical cells. − , …”

“…Inspired mostly by the interesting photoelectrochemical energy conversion properties exhibited by GO-based film electrodes, − ,− we have investigated the photoelectrochemical properties of the (GO/RuL) n films. Figure shows the photocurrent responses induced by switching on and off a polychromatic light irradiation (325 nm < λ < 730 nm) on the (GO/RuL) 1 film at an applied potential of −0.4–0.2 V versus SCE.…”

“…The polypyridylruthenium(II) complexes have attracted tremendous attention due to their strong visible light harvesting property, excellent chemical stability, and highly applicable ground- and excited-state photochemical, photophysical, and redox properties as well as versatile excited-state energy and electron-transfer processes. To date, many Ru(II) complexes have been introduced into LBL films by using Langmuir–Blodgett , and covalent , and electrostatical − self-assembly techniques. These films have shown interesting optical and redox properties and found numberous applications in fields such as second-order nonlinear optics, molecular catalysis, energy storage and conversion devices, and molecular sensors and biosensors.…”

Synergistically enhanced photoelectrochemical properties of a layer-by-layer hybrid film based on graphene oxide and a free terpyridyl-grafted ruthenium complex

“…ITO/(GO/Ru3) 1 ), 20 0.762 mA (2.72 mA cm À2 ) for a covalently self-assembled thin lm based on a bis-terpyridyl Ru(II) complex of [Ru II (IPTP) 2 ] 2+ (in which IPTP ¼ 4 0 -(4-(imidazol-1-yl)phenyl)-2,2 0 :6 0 ,2 00 -terpyridine), 39 . 40 Stable and prompt photocurrent responses were generated reversibly and repeatedly under on/off cycles of irradiation. This behaviour is in contrast to the much slower and weaker photocurrent responses previously reported for an ESA lm of polymerized Ru(II) complex with [S 2 Mo 18 O 62 ] 4À .…”

Cancer control and prevention

“…Dietary intake information was based on a standard food frequency questionnaire. Urine Bladder cancer (methylation profiling) [125,126] study because head and neck cancer is most often associated with long-time exposure to tobacco and HPV [128,129]. Genes that were differentially methylated in this study included CHGA, HGF, HOXA11, GML, LNC2, MLF1, PTR1, RARB, SFN, SIN3B, SRC, THPO, and XIST.…”