Isolation and evaluation of erythroid progenitors in the livers of larval, froglet, and adult Xenopus tropicalis.

Xenopus liver maintains erythropoietic activity from the larval to the adult stage. During metamorphosis, thyroid hormone mediates apoptosis of larval-type erythroid progenitors and proliferation of adult-type erythroid progenitors, and a globin switch occurs during this time. In addition, the whole-body mass and the liver also change; however, whether there is a change in the absolute number of erythroid progenitors is unclear.

Efficient Visible-Light-Driven CO Reduction by a Cobalt Molecular Catalyst Covalently Linked to Mesoporous Carbon Nitride.

Achieving visible-light-driven carbon dioxide reduction with high selectivity control and durability while using only earth abundant elements requires new strategies. Hybrid catalytic material was prepared upon covalent grafting a Co-quaterpyridine molecular complex to semiconductive mesoporous graphitic carbon nitride (mpg-CN) through an amide linkage. The molecular material was characterized by various spectroscopic techniques, including XPS, IR, and impedance spectroscopy.

Graphitic carbon nitride prepared from urea as a photocatalyst for visible-light carbon dioxide reduction with the aid of a mononuclear ruthenium(II) complex.

Graphitic carbon nitride (g-CN) was synthesized by heating urea at different temperatures (773-923 K) in air, and was examined as a photocatalyst for CO reduction. With increasing synthesis temperature, the conversion of urea into g-CN was facilitated, as confirmed by X-ray diffraction, FTIR spectroscopy and elemental analysis. The as-synthesized g-CN samples, further modified with Ag nanoparticles, were capable of reducing CO into formate under visible light (λ > 400 nm) in the presence of triethanolamine as an electron donor, with the aid of a molecular Ru(II) cocatalyst (RuP).

A Carbon Nitride/Fe Quaterpyridine Catalytic System for Photostimulated CO-to-CO Conversion with Visible Light.

Efficient and selective photostimulated CO-to-CO reduction by a photocatalytic system consisting of an iron-complex catalyst and a mesoporous graphitic carbon nitride (mpg-CN) redox photosensitizer is reported for the first time. Irradiation in the visible region (λ ≥ 400 nm) of an CHCN/triethanolamine (4:1, v/v) solution containing [Fe(qpy)(HO)] (qpy = 2,2':6',2'':6'',2''-quaterpyridine) and mpg-CN resulted in CO evolution with 97% selectivity, a turnover number of 155, and an apparent quantum yield of ca. 4.

Undoped Layered Perovskite Oxynitride Li LaTa O N for Photocatalytic CO Reduction with Visible Light.

Oxynitrides are promising visible-light-responsive photocatalysts, but their structures are almost confined with three-dimensional (3D) structures such as perovskites. A phase-pure Li LaTa O N with a layered perovskite structure was successfully prepared by thermal ammonolysis of a lithium-rich oxide precursor. Li LaTa O N exhibited high crystallinity and visible-light absorption up to 500 nm.

A Stable, Narrow-Gap Oxyfluoride Photocatalyst for Visible-Light Hydrogen Evolution and Carbon Dioxide Reduction.

Mixed anion compounds such as oxynitrides and oxychalcogenides are recognized as potential candidates of visible-light-driven photocatalysts since, as compared with oxygen 2p orbitals, p orbitals of less electronegative anion (e.g., N, S) can form a valence band that has more negative potential.

Interfacial Manipulation by Rutile TiO Nanoparticles to Boost CO Reduction into CO on a Metal-Complex/Semiconductor Hybrid Photocatalyst.

Metal-complex/semiconductor hybrids have attracted attention as photocatalysts for visible-light CO reduction, and electron transfer from the metal complex to the semiconductor is critically important to improve the performance. Here rutile TiO nanoparticles having 5-10 nm in size were employed as modifiers to improve interfacial charge transfer between semiconducting carbon nitride nanosheets (NS-CN) and a supramolecular Ru(II)-Re(I) binuclear complex (RuRe). The RuRe/TiO/NS-CN hybrid was capable of photocatalyzing CO reduction into CO with high selectivity under visible light (λ > 400 nm), outperforming an analogue without TiO by a factor of 4, in terms of both CO formation rate and turnover number (TON).

Robust Binding between Carbon Nitride Nanosheets and a Binuclear Ruthenium(II) Complex Enabling Durable, Selective CO Reduction under Visible Light in Aqueous Solution.

Carbon nitride nanosheets (NS-C N ) were found to undergo robust binding with a binuclear ruthenium(II) complex (RuRu') even in basic aqueous solution. A hybrid material consisting of NS-C N (further modified with nanoparticulate Ag) and RuRu' promoted the photocatalytic reduction of CO to formate in aqueous media, in conjunction with high selectivity (approximately 98 %) and a good turnover number (>2000 with respect to the loaded Ru complex). These represent the highest values yet reported for a powder-based photocatalytic system during CO reduction under visible light in an aqueous environment.

Development of hybrid photocatalysts constructed with a metal complex and graphitic carbon nitride for visible-light-driven CO reduction.

Photocatalytic CO reduction with visible light has long been studied as a potential means to address the problems of global warming and the depletion of fossil fuels. Hybrid systems that consist of a metal complex and a particulate semiconductor are expected to be promising because of the excellent electrochemical (and/or photocatalytic) ability of metal complexes for CO reduction and the high efficiency of semiconductors for water oxidation. However, a satisfactory system has not been developed to date.

Nature-Inspired, Highly Durable CO2 Reduction System Consisting of a Binuclear Ruthenium(II) Complex and an Organic Semiconductor Using Visible Light.

A metal-free organic semiconductor of mesoporous graphitic carbon nitride (C3N4) coupled with a Ru(II) binuclear complex (RuRu') containing photosensitizer and catalytic units selectively reduced CO2 into HCOOH under visible light (λ > 400 nm) in the presence of a suitable electron donor with high durability, even in aqueous solution. Modification of C3N4 with Ag nanoparticles resulted in a RuRu'/Ag/C3N4 photocatalyst that exhibited a very high turnover number (>33000 with respect to the amount of RuRu'), while maintaining high selectivity for HCOOH production (87-99%). This turnover number was 30 times greater than that reported previously using C3N4 modified with a mononuclear Ru(II) complex, and by far the highest among the metal-complex/semiconductor hybrid systems reported to date.

Unique Solvent Effects on Visible-Light CO2 Reduction over Ruthenium(II)-Complex/Carbon Nitride Hybrid Photocatalysts.

Photocatalytic CO2 reduction using hybrids of carbon nitride (C3N4) and a Ru(II) complex under visible light was studied with respect to reaction solvent. Three different Ru(II) complexes, trans(Cl)-[Ru(X2bpy) (CO)2Cl2] (X2bpy = 2,2'-bipyridine with substituents X in the 4-positions, X = COOH, PO3H2, or CH2PO3H2), were employed as promoters and will be abbreviated as RuC (X = COOH), RuP (X = PO3H2), and RuCP (X = CH2PO3H2). When C3N4 modified with a larger amount of RuCP (>7.

Visible-light-driven CO2 reduction with carbon nitride: enhancing the activity of ruthenium catalysts.

A heterogeneous photocatalyst system that consists of a ruthenium complex and carbon nitride (C3N4), which act as the catalytic and light-harvesting units, respectively, was developed for the reduction of CO2 into formic acid. Promoting the injection of electrons from C3N4 into the ruthenium unit as well as strengthening the electronic interactions between the two units enhanced its activity. The use of a suitable solvent further improved the performance, resulting in a turnover number of greater than 1000 and an apparent quantum yield of 5.