Graphene Mediates Charge Transfer between Lead Chromate and a Cobalt Cubane Cocatalyst for Photocatalytic Water Oxidation.

The interfacial barrier of charge transfer from semiconductors to cocatalysts means that the photogenerated charges cannot be fully utilized, especially for the challenging water oxidation reaction. Using cobalt cubane molecules (Co4 O4 ) as water oxidation cocatalysts, we rationally assembled partially oxidized graphene (pGO), acting as a charge-transfer mediator, on the hole-accumulating {-101} facets of lead chromate (PbCrO4 ) crystal. The assembled pGO enables preferable immobilization of Co4 O4 molecules on the {-101} facets of the PbCrO4 crystal, which is favorable for the photogenerated holes transferring from PbCrO4 to Co4 O4 molecules. The surface charge-transfer efficiency of PbCrO4 was boosted by selective assembly of pGO between PbCrO4 and Co4 O4 molecules. An apparent quantum efficiency for photocatalytic water oxidation on the Co4 O4 /pGO/PbCrO4 photocatalyst exceeded 10 % at 500 nm. This strategy of rationally assembling charge-transfer mediator provides a feasible method for acceleration of charge transfer and utilization in semiconductor photocatalysis.

Expression analysis of three immune genes Interferon-gamma, Mx and Interferon regulatory factor-1 of Japanese flounder ( Paralichthys olivaceus )

ABSTRACT IFN-γ (Interferon-gamma), Mx and IRF-1 (Interferon regulatory factor-1) are main immune-related genes and they play important roles in the innate immune system of vertebrates. In this study, the expression level of the three immune-related genes in twelve tissues of normal adult Japanese flounder was detected using semi-quantitative RT-PCR. Thirteen time points (3h, 6h, 9h, 12h, 24h, 36h, 48h, 60h, 72h, 84h, 96h, 108h, 120h) were selected to analyze the expression of IFN-γ, Mx and IRF-1 in spleen, head kidney, liver of Japanese flounder infected with Lipopolysaccharide (LPS). The Japanese flounder IFN-γ, Mx and IRF-1 genes were differently expressed in these tissues and had high expression levels in classical fish immune organs like spleen and head kidney. It was found that the highest expression levels of the Japanese flounder IFN-γ were detected at 24h in spleen, 36h in head kidney and 48h in liver after challenge with LPS. Interestingly, the highest expression levels of Mx in spleen and head kidney were both at 36h and IRF-1 in spleen and liver were both at 24h. The highest expression level of Mx in liver was at 48h and IRF-1 in head kidney was at 12h. The study provides a basis for further research on immune mechanism of IFN-γ, Mx, IRF-1 and the production of recombinant IFN-γ, Mx or IRF-1 used in Japanese flounder cultivation in future.