Showing papers by "Akira Fujishima published in 1994"
TL;DR: Results suggested that the cell membrane permeability to Ca2+ was promoted prior to cell death, and it was confirmed that malignant cells are inactivated by photo-excited TiO2 particles.
105 citations
TL;DR: In this article, a Pd electrode surface was modified with Cu and used for the electrochemical reduction of CO2 in aqueous KHCO3 solution, and the effect of hydrogen absorption on the reaction has been clarified using the Cu-modified electrode.
39 citations
TL;DR: A simple technique for creating etch pits in muscovite mica substrates for calibration purposes in atomic force microscopy (AFM) and it is these 1‐ and 2‐nm‐high steps that permit height calibration.
Abstract: We describe a simple technique for creating etch pits in muscovite mica substrates for calibration purposes in atomic force microscopy (AFM). The etch pits are produced by wet etching the mica substrates in concentrated hydrofluoric acid and are formed with specific geometry. Along the long axis of the etch pits, steps of approximately 2 nm are observed which correspond to the molecular planes of mica. These steps bifurcate into 1 nm steps along the short axis. It is these 1‐ and 2‐nm‐high steps that permit height calibration.
36 citations
TL;DR: Raman microprobe spectroscopy has been used to study the electrochromic and photochromic thin films of MoO3 and WO3 as mentioned in this paper, and it was found that after subjecting to cathodic polarization or UV irradiation, exhibited several Raman peaks at 112, 124, 150, 283, 336, 376, 663, 820 and 994 cm−1.
35 citations
TL;DR: In this article, a new electroless plating process for preparing a copper layer with strong adhesion to glass substrates was developed, which incorporates a ZnO thin film on the glass substrate, instead of etching and sensitizing the substrate surface as in a conventional electroless-plating process.
Abstract: A new electroless plating process for preparing a copper layer with strong adhesion to glass substrates was developed. This process incorporates a ZnO thin film on the glass substrate, instead of etching and sensitizing the substrate surface as in a conventional electroless plating process. The copper layer so obtained had a mirror-like finish while maintaining strong adhesion, even on a very smooth glass surface (Ra<0.01 μm). The bond strength measured by pull tests was more than 10 kg per 2 mm×2 mm square (kg/2 mm□), much greater than that obtained using conventional electroless plating (∼1 kg/2 mm□) and suitable for use in printed circuit boards. We find the ZnO thin film to serve as a kind of «adhesive» between the metal layer and glass substrate
26 citations
TL;DR: In this article, a novel electrochemical CO[sub 2] reduction system was developed in which liquid CO was reduced electrochemically at a Cu electrode producing CO, CH, CH[sub 4], C[sub 3], H[sub 5], and HCOOCH[sub 6] with a current density of 420 mA/cm[sup 2] and a current efficiency of 85%.
Abstract: A novel electrochemical CO[sub 2] reduction system has been developed in which liquid CO[sub 2] was reduced electrochemically at a Cu electrode producing CO, CH[sub 4], C[sub 2]H[sub 4], and HCOOCH[sub 3]. The authors have succeeded in reducing CO[sub 2] with a current density of 420 mA/cm[sup 2] and a current efficiency of 85%; the former is higher than that used in industrial electrolysis such as in the chloralkali industry. The Tafel plots indicate that the supply of CO[sub 2] is no longer limited by its mass transfer.
25 citations
23 citations
TL;DR: In this paper, the distribution of reaction products at the irradiated surface of a TiO 2 -ITO composite film was measured electrochemically using a carbon disk microelectrode located adjacent to the film surface (50-500 μm).
20 citations
TL;DR: In this article, current topics in photochemistry and photoelectrochemistry of thin semiconductor films are presented in regards to technological applications Examples include photelectrochemical reduction of CO2, photocatalytic applications for deodorization, metalization via photochemical reactions, and the photochromic behavior of MoO3
14 citations
TL;DR: In this article, a photoelectrochemical molecular system was found to constitute a new three-state molecular system, which is attributed to having a common species produced from either photoinduced open-ring or closed-ring isomers by electron transfer.
Abstract: 1,3,3-trimethyl-6-nitrospiro(2H-1-benzopyran-2,2′-indoline) in DMF at −42 °C was found to constitute a new “three state” photoelectrochemical molecular system. This behavior is attributed to having a common species produced from either photoinduced open-ring or closed-ring isomers by electron transfer, namely, a radical anion of the closed-ring by reduction and an open-ring isomer by oxidation.
9 citations
TL;DR: In this paper, atomic force microscopy (AFM) images revealed that small alloy protrusions form initially next to the Au grain boundaries and gradually increase in size with increased deposition time.
Abstract: Bulk electrochemical deposition of mercury on Au(111) electrode surface in an acidic media, resulting in the formation of a Au-Hg alloy, has been studied in-situ by atomic force microscopy (AFM). AFM images revealed that small alloy protrusions form initially next to the Au grain boundaries and gradually increase in size with increased deposition time. More importantly, these protrusions are always accompanied by the dissolution of gold at the grain boundaries, leaving many apparent pits visible on the amalgamated surface.
TL;DR: In this article, two novel cis-trans conversion pathways have been studied using assembled monolayer films of azobenzene derivative on solid electrodes and showed that electrostatic isomerization induced by strong electric field at the interface of electrode and electrolyte leads to inverted redox reactions which leads to the simultaneous conversion of cis-ABD to the trans isomer at UV light irradiation.
Abstract: Two novel cis-trans conversion pathways have been studied using the assembled monolayer films of azobenzene derivative on solid electrodes The first one is electrostatic isomerization induced by strong electric field at the interface of electrode and electrolyte The second one is inverted redox reactions which leads to the simultaneous conversion of cis-ABD to the trans isomer at UV light irradiation These reactions may provide new strategies to the chromic applications of azobenzene
TL;DR: In this article, the photoelectrochemical properties of Re 6 Se 7 Br 4 were investigated in aqueous electrolytes and the spectral response indicated an indirect band gap of about 1.78 eV for the compound.
TL;DR: In this paper, a new electroless plating process for preparing a copper layer with strong adhesion to glass substrates was developed, which incorporates a ZnO thin film on the glass substrate, instead of etching and sensitizing the substrate surface as in a conventional electroless-plating process.
Abstract: A new electroless plating process for preparing a copper layer with strong adhesion to glass substrates was developed. This process incorporates a ZnO thin film on the glass substrate, instead of etching and sensitizing the substrate surface as in a conventional electroless plating process. The copper layer so obtained had a mirror-like finish while maintaining strong adhesion, even on a very smooth glass surface (Ra<0.01 μm). The bond strength measured by pull tests was more than 10 kg per 2 mm×2 mm square (kg/2 mm□), much greater than that obtained using conventional electroless plating (∼1 kg/2 mm□) and suitable for use in printed circuit boards. We find the ZnO thin film to serve as a kind of «adhesive» between the metal layer and glass substrate
01 Jan 1994
TL;DR: In this paper, two novel photoresponsive systems utilizing photochemical and electrochemical techniques are presented for information storage, one is to limit the illumination area of the trans to cis isomerization with a focused laser beam; however, the storage density is limited by the optical diffraction limit of the laser spot.
Abstract: Two novel photoresponsive systems utilizing photochemical and electrochemical techniques are presented. First, we have studied the photoelectrochemical behavior of several amphiphilic azobenzene derivatives (ABD) in assembled monolayer films and reported a unique route-specific hybrid phenomenon. The phenomenon is based on the following two observations: 1) cis-ABD in the monolayer film is reduced to hydrazobenzene (-NH-NH-) (HBD) at substantially more anodic potential than the trans isomer; 2) HBD is reoxidized only to trans-ABD and not to cis-ABD. These three states are linked together and thus can form a new memory system. For information storage, two means are possible. One is to limit the illumination area of the trans to cis isomerization with a focused laser beam; however, the storage density is limited by the optical diffraction limit of the laser spot (~108 bits/cm2). The other way is localized the electrochemical reduction area using a microelectrode controlled by scanning probe techniques. With this means, much higher density is expected (~1012 bits/cm2). In the second photoresponsive system, we have succeeded in obtaining visible light sensitive photochromism using MoO3. Pretreated MoO3 vacuum evaporated thin films, which were slightly blued by cathodic polarization in a nonaqueous electrolyte (electrochromism), showed strong color enhancement when irradiation in air by visible light. These films could be easily erased by anodic polarization in a nonaqueous electrolyte, with the coloration-decoloration process being reversible. This is in contrast to thin films which are blued in advanced by the band-gap irradiation in air, where a response to visible light irradiation does not occur. The MoO3 film is believed to change to an intermediate metastable state during the electrolytic pretreatment which is then converted by visible light into stable molybdenum bronze.
TL;DR: In this paper, an atomic force microscope (AFM) was adapted for the purpose of performing surface photovoltage (SPV) spectroscopy, where SPV spectra were obtained from p-type Si and TiO2 test samples over a wavelength region between 300-800 nm.
Abstract: We have adapted an atomic force microscope (AFM) for the purpose of performing surface photovoltage (SPV) spectroscopy. SPV spectra were obtained from p-type Si (100) and TiO2 (100) test samples over a wavelength region between 300–800 nm. Simultaneous AFM topography and SPV mapping was also conducted. The boundary between a polymer coating and bare Si substrate was used to test the mapping capability.
01 Jan 1994
TL;DR: This article used scanning probe microscopy to investigate the molecular orientation of various naphthalocyanine (Nc) thin films as a function of substrate temperature and found that metal-Nc molecules grew in a more ordered fashion with even epitaxial behavior under certain conditions.
Abstract: We have used scanning probe microscopy to investigate the molecular orientation of various naphthalocyanine (Nc) thin films as a function of substrate temperature. Films deposited under ambient temperature exhibited an amorphous structure; however at elevated temperatures, metal-Nc molecules grew in a more ordered fashion with even epitaxial behavior under certain conditions. Specifically, we found that cobalt Nc (CoNc) molecules deposited onto NaCl at 250°C grew with the molecular planes perpendicular to the underlying substrate. In contrast, vanadyl-Nc (VONc) deposited onto highly oriented pyrolytic graphite (HOPG) tended to show a more epitaxial growth behavior with the molecules slightly tilted with respect to the HOPG substrate.