Osamu Ishitani

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-C₃N₄) through an amide linkage. The molecular material was characterized by various spectroscopic techniques, including XPS, IR, and impedance spectrosc

Carbon nitride nanosheets (NS-C₃ N₄ ) were found to undergo robust binding with a binuclear ruthenium(II) complex (RuRu') even in basic aqueous solution. A hybrid material consisting of NS-C₃ N₄ (further modified with nanoparticulate Ag) and RuRu' promoted the photocatalytic reduction of CO₂ to formate in aqueous media, in conjunction with high selectivity (approximately 98 %) and a good turnover number (>2000 with respect to the loaded Ru c

A photocatalytic system with a Mn(I) complex as a catalyst and a Ru(II) complex as a photosensitizer efficiently reduced CO2 to formic acid.

ConspectusPhotocatalytic CO₂ reduction is a critical objective in the field of artificial photosynthesis because it can potentially make a total solution for global warming and shortage of energy and carbon resources. We have successfully developed various highly efficient, stable, and selective photocatalytic systems for CO₂ reduction using transition metal complexes as both photosensitizers and catalysts. The molecular architectures for constructing selective and efficien

Efficient and selective photostimulated CO₂-to-CO reduction by a photocatalytic system consisting of an iron-complex catalyst and a mesoporous graphitic carbon nitride (mpg-C₃N₄) redox photosensitizer is reported for the first time. Irradiation in the visible region (λ ≥ 400 nm) of an CH₃CN/triethanolamine (4:1, v/v) solution containing [Fe(qpy)(H₂O)₂]²⁺ (qpy = 2,2':6',2'':6'',2''-quaterpyridine) and mpg-C₃N<

The development of highly efficient, selective, and durable photocatalytic CO₂ reduction systems that only use earth-abundant elements is key for both solving global warming and tackling the shortage of energy and carbon resources. Here, we successfully developed CO₂ reduction photocatalysts using [Cu₂(P₂bph)₂]²⁺ (CuPS) (P₂bph = 4,7-diphenyl-2,9-di(diphenylphosphinotetramethylene)-1,10-phenanthroline) as a redox photose

A CuGaO₂ p-type semiconductor electrode was successfully employed for constructing a new hybrid photocathode with a Ru(ii)-Re(i) supramolecular photocatalyst (<b>RuRe</b>/CuGaO₂). The <b>RuRe</b>/CuGaO₂ photocathode displayed photoelectrochemical activity for the conversion of CO₂ to CO in an aqueous electrolyte solution with a positive onset potential of +0.3 V <i>vs.</i> Ag/AgCl, which is 0.4 V more positive in comparison to a previously reported hyb

We discovered an extremely suitable sacrificial electron donor, 1,3-dimethyl-2-(<i>o</i>-hydroxyphenyl)-2,3-dihydro-1<i>H</i>-benzo[<i>d</i>]imidazole, for the selective photocatalytic reduction of CO₂ to formic acid using a Ru(ii)-Ru(ii) supramolecular photocatalyst. The efficiency, durability, and rate of photocatalysis are significantly increased (<i>Φ</i>_HCOOH = 0.46, TON_HCOOH = 2766, TOF_HCOOH = 44.9 min^-1) in comparison with those using

Increasing concentration of atmospheric CO₂ is a worldwide concern and continues to trigger various environmental problems. Photo- or electrocatalytic CO₂ reduction (CO₂-Red) using solar energy, i.e., artificial photosynthesis, is a prospective technique owing to its sustainability and the usefulness of the reaction products. Concentrations of CO₂ in exhaust gases from industries are several % to 20%, and that in the atmosphere is about 400 ppm. Althou