There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

THE large-scale use of photovoltaic devices for electricity generation is prohibitively expensive at present: generation from existing commercial devices costs about ten times more than conventional methods1. Here we describe a photovoltaic cell, created from low-to medium-purity materials through low-cost processes, which exhibits a commercially realistic energy-conversion efficiency. The device is based on a 10-µm-thick, optically transparent film of titanium dioxide particles a few nanometres in size, coated with a monolayer of a charge-transfer dye to sensitize the film for light harvesting. Because of the high surface area of the semiconductor film and the ideal spectral characteristics of the dye, the device harvests a high proportion of the incident solar energy flux (46%) and shows exceptionally high efficiencies for the conversion of incident photons to electrical current (more than 80%). The overall light-to-electric energy conversion yield is 7.1-7.9% in simulated solar light and 12% in diffuse daylight. The large current densities (greater than 12 mA cm-2) and exceptional stability (sustaining at least five million turnovers without decomposition), as well as the low cost, make practical applications feasible.

A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films

To use solar irradiation or interior lighting efficiently, we sought a photocatalyst with high reactivity under visible light. Films and powders of TiO 2- x N x have revealed an improvement over titanium dioxide (TiO 2 ) under visible light (wavelength 2 has proven to be indispensable for band-gap narrowing and photocatalytic activity, as assessed by first-principles calculations and x-ray photoemission spectroscopy.

/pdf/visible-light-photocatalysis-in-nitrogen-doped-titanium-np6nklr9gh.pdf

Visible-Light Photocatalysis in Nitrogen-Doped Titanium Oxides

Titanium Dioxide Nanomaterials: Synthesis, Properties, Modifications, and Applications

https://robots.iopscience.iop.org/article/10.1149/2.0741508jes/pdf

Influence of Boron-Doped Diamond Surface Termination on the Characteristics of Titanium Dioxide Anodically Deposited in the Presence of a Surfactant

An air purification system includes an internally hollow cylindrical casing made of a non-conducting material; an inner electrode arranged on an inner surface of the supporting member; an outer electrode arranged on an outer surface of the supporting member; a photocatalyst filter arranged on an outer surface of the outer electrode for purifying air inside a plasma generation zone; and a power source for supplying power of opposite polarities to each of the inner electrode and the outer electrode so as to generate plasma. The photocatalyst filter includes a filter element, and the filter element includes a porous titanium foil having a non-periodic spongy structure impregnated with anatase titanium dioxide particles as a photocatalyst.

Air purification system

High-speed synthesis of heavily boron-doped diamond films by in-liquid microwave plasma CVD

A series of dye-included metal complex-based magnets, DAMS[MCr (ox)3] (DAMS+ = 4-[2-(4-dimethylaminophenyl)ethenyl]-l-methylpyridinium cation; M2+=Mn2+, Fe2+, Ni2+; ox2- =Oxalate Ion), were synthesized. In these compounds different kinds of metal cations are bridged to each other by ox2- ions. The compounds have a layered-structure and molecules of DAMS+ are enclathrated between the layers. Field-cooled magnetization (FCM) measurement showed that these compounds exhibit magnetic phase transition at 10K, 14K, and 18K respectively.

Syntheses and Magnetic Properties of Dye Included Organometallic Magnets: DAMS[MCr(ox)3]

Three new ferrocenyl oxadiazoles, viz. (E)-2-(4-hydroxyphenyl)-5-(2-ferrocenyl-ethen-1-yl)-1,3,4-oxadiazole (D2), (E)-2-(4-nitrophenyl)-5-(2-ferrocenyl-ethen-1-yl)-1,3,4-oxadiazole (D3) and (E)-3-(4-nitrophenyl)-5-[5-(2-ferroceneylethen-1-yl)-1,3,4-oxadiazol-2-yl]-1,2,4-oxadiazole (D4) derived from (E)-3-ferrocenylacrylic acid (D1) having phenolic or nitro anchors, have been synthesized and characterized using microanalyses and relevant spectroscopic techniques. UV-Vis spectroscopic studies indicate that with respect to ferrocene, the electronic absorption bands of the new compounds are bathochromically shifted up to 600 nm with a concomitant enhancement in their intensities. All four compounds have been used as photosensitizers in TiO2-based dye-sensitized solar cells (DSSCs). The photovoltaic performances and charge transport properties (EIS spectra) of these compounds were studied to appraise their dye performance. All four compounds displayed good photovoltaic performances. However, compounds D2 and D4 displayed superior performance, which might be due to the better electronic communication between the ferrocenyl moiety and the six membered aromatic ring with their –OH/NO2 anchors having five membered oxadiazole spacers, as well as the high dye loading of these compounds on the TiO2 surface, which suppresses charge recombination, prolongs electron lifetime, and decreases the total resistance of DSSCs. The assembly fabricated using D4 performed better with an overall conversion efficiency η of 4.70%, Jsc of 10.33 mA cm−2 and Voc of −0.712 V.

Akira Fujishima

Papers

Influence of Boron-Doped Diamond Surface Termination on the Characteristics of Titanium Dioxide Anodically Deposited in the Presence of a Surfactant

Air purification system

High-speed synthesis of heavily boron-doped diamond films by in-liquid microwave plasma CVD

Syntheses and Magnetic Properties of Dye Included Organometallic Magnets: DAMS[MCr(ox)3]

Ferrocenylethenyl-substituted oxadiazoles with phenolic and nitro anchors as sensitizers in dye sensitized solar cells