Interaction between dye and zinc in the dye-dispersing ZnO films prepared by a wet process

Dye-dispersing ZnO precursor gel films were prepared on indium tin oxide electrodes from a zinc acetate solution containing eosin Y by dip-coating, steam treatment, and then heating at a low temperature. The electronic interaction between the dye and zinc in the dye-dispersing gel films were investigated by spectroscopic and electrochemical measurements. A photocurrent was observed in the dye-dispersing gel electrodes before the steam treatment. The photocurrent value increased by the steam treatment and heating due to crystallization of the gel and removal of organic impurities. The dye molecules existed between the interlayers of the layered zinc hydroxide coexisting with the ZnO. The photoexcited electron in the dye should be injected into the ZnO conduction band via the layered zinc hydroxide. The value increased with an increase in the dye content even though the ZnO crystallinity decreased. The dye-zinc interaction, i.e., the complex formation and photoinduced electron injection, played an important role in the electron transport and photoelectric conversion.ArticleRESEARCH ON CHEMICAL INTERMEDIATES. 41(9):6559-6574 (2015)journal articl

Formation of ZnO thin films by photocatalytic reaction

Zinc oxide and layered zinc hydroxides were deposited from an aqueous solution of zinc nitrate at 323–358 K on a substrate plate with a very thin titanium dioxide film by a photocatalytic reaction. The amorphous or low crystalline zinc hydroxide aggregates were deposited at a low temperature. The zinc oxide crystals with about 1–2 μm-sized hexagonal columns and 10 nm-sized spheres were formed at 338–358 K. Nitrate ions in the solution were reduced to nitrite ions, and water was transformed into hydroxide ions by a photocatalytic reaction on the titanium dioxide film. The pH value increased on the substrate surface with the titanium dioxide film, which caused the zinc hydroxide formation on the film. The zinc hydroxides were then dehydrated and transformed into zinc oxide. The average crystallite size of the zinc oxide decreased with an increase in the reaction temperature because the reaction rates of the formation and dehydration of the zinc hydroxides increased which resulted in an increase in the formation rate of the crystal zinc oxide nuclei.ArticleAPPLIED CATALYSIS B-ENVIRONMENTAL. 160:651-657 (2014)journal articl

Formation of ZnO thin films by photocatalytic reaction

Zinc oxide and layered zinc hydroxides were deposited from an aqueous solution of zinc nitrate at 323–358 K on a substrate plate with a very thin titanium dioxide film by a photocatalytic reaction. The amorphous or low crystalline zinc hydroxide aggregates were deposited at a low temperature. The zinc oxide crystals with about 1–2 μm-sized hexagonal columns and 10 nm-sized spheres were formed at 338–358 K. Nitrate ions in the solution were reduced to nitrite ions, and water was transformed into hydroxide ions by a photocatalytic reaction on the titanium dioxide film. The pH value increased on the substrate surface with the titanium dioxide film, which caused the zinc hydroxide formation on the film. The zinc hydroxides were then dehydrated and transformed into zinc oxide. The average crystallite size of the zinc oxide decreased with an increase in the reaction temperature because the reaction rates of the formation and dehydration of the zinc hydroxides increased which resulted in an increase in the formation rate of the crystal zinc oxide nuclei.ArticleAPPLIED CATALYSIS B-ENVIRONMENTAL. 160:651-657 (2014)journal articl

Long-Term Efficacy and Safety of Rifaximin in Japanese Patients with Hepatic Encephalopathy: A Multicenter Retrospective Study

Background: Rifaximin is commonly used for hepatic encephalopathy (HE). However, the effects of long-term treatment for Japanese people are limited. Therefore, this study aimed to investigate the effects and safety of long-term treatment with rifaximin on HE. Methods: A total of 215 patients with cirrhosis administered with rifaximin developed overt or covert HE, which was diagnosed by an attending physician for >12 months. Laboratory data were extracted at pretreatment and 3, 6, and 12 months after rifaximin administration. The long-term effect of rifaximin was evaluated, and the incidence of overt HE during 12 months and adverse events was extracted. Results: Ammonia levels were significantly improved after 3 months of rifaximin administration and were continued until 12 months. There were no serious adverse events after rifaximin administration. The number of overt HE incidents was 9, 14, and 27 patients within 3, 6, and 12 months, respectively. Liver enzymes, renal function, and electrolytes did not change after rifaximin administration. Prothrombin activity is a significant risk factor for the occurrence of overt HE. The serum albumin, prothrombin activity, and albumin–bilirubin (ALBI) scores were statistically improved after 3 and 6 months of rifaximin administration. Moreover, the same results were obtained in patients with Child–Pugh C. Conclusions: The long-term rifaximin treatment was effective and safe for patients with HE, including Child–Pugh C

Interaction between dye and zinc in the dye-dispersing ZnO films prepared by a wet process

Dye-dispersing ZnO precursor gel films were prepared on indium tin oxide electrodes from a zinc acetate solution containing eosin Y by dip-coating, steam treatment, and then heating at a low temperature. The electronic interaction between the dye and zinc in the dye-dispersing gel films were investigated by spectroscopic and electrochemical measurements. A photocurrent was observed in the dye-dispersing gel electrodes before the steam treatment. The photocurrent value increased by the steam treatment and heating due to crystallization of the gel and removal of organic impurities. The dye molecules existed between the interlayers of the layered zinc hydroxide coexisting with the ZnO. The photoexcited electron in the dye should be injected into the ZnO conduction band via the layered zinc hydroxide. The value increased with an increase in the dye content even though the ZnO crystallinity decreased. The dye-zinc interaction, i.e., the complex formation and photoinduced electron injection, played an important role in the electron transport and photoelectric conversion.ArticleRESEARCH ON CHEMICAL INTERMEDIATES. 41(9):6559-6574 (2015)journal articl