[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

The production of hydrogen from water using a catalyst and solar energy is an ideal future energy source, independent of fossil reserves. For an economical use of water and solar energy, catalysts that are sufficiently efficient, stable, inexpensive and capable of harvesting light are required. Here, we show that an abundant material, polymeric carbon nitride, can produce hydrogen from water under visible-light irradiation in the presence of a sacrificial donor. Contrary to other conducting polymer semiconductors, carbon nitride is chemically and thermally stable and does not rely on complicated device manufacturing. The results represent an important first step towards photosynthesis in general where artificial conjugated polymer semiconductors can be used as energy transducers.

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A metal-free polymeric photocatalyst for hydrogen production from water under visible light

This critical review shows the basis of photocatalytic water splitting and experimental points, and surveys heterogeneous photocatalyst materials for water splitting into H2 and O2, and H2 or O2 evolution from an aqueous solution containing a sacrificial reagent Many oxides consisting of metal cations with d0 and d10 configurations, metal (oxy)sulfide and metal (oxy)nitride photocatalysts have been reported, especially during the latest decade The fruitful photocatalyst library gives important information on factors affecting photocatalytic performances and design of new materials Photocatalytic water splitting and H2 evolution using abundant compounds as electron donors are expected to contribute to construction of a clean and simple system for solar hydrogen production, and a solution of global energy and environmental issues in the future (361 references)

Heterogeneous photocatalyst materials for water splitting

Energy harvested directly from sunlight offers a desirable approach toward fulfilling, with minimal environmental impact, the need for clean energy. Solar energy is a decentralized and inexhaustible natural resource, with the magnitude of the available solar power striking the earth’s surface at any one instant equal to 130 million 500 MW power plants.1 However, several important goals need to be met to fully utilize solar energy for the global energy demand. First, the means for solar energy conversion, storage, and distribution should be environmentally benign, i.e. protecting ecosystems instead of steadily weakening them. The next important goal is to provide a stable, constant energy flux. Due to the daily and seasonal variability in renewable energy sources such as sunlight, energy harvested from the sun needs to be efficiently converted into chemical fuel that can be stored, transported, and used upon demand. The biggest challenge is whether or not these goals can be met in a costeffective way on the terawatt scale.2

http://pubs.acs.org/doi/pdf/10.1021/cr1002326

Solar Water Splitting Cells

2.3. Evaluation of Photocatalytic Water Splitting 6507 2.3.1. Photocatalytic Activity 6507 2.3.2. Photocatalytic Stability 6507 3. UV-Active Photocatalysts for Water Splitting 6507 3.1. d0 Metal Oxide Photocatalyts 6507 3.1.1. Ti-, Zr-Based Oxides 6507 3.1.2. Nb-, Ta-Based Oxides 6514 3.1.3. W-, Mo-Based Oxides 6517 3.1.4. Other d0 Metal Oxides 6518 3.2. d10 Metal Oxide Photocatalyts 6518 3.3. f0 Metal Oxide Photocatalysts 6518 3.4. Nonoxide Photocatalysts 6518 4. Approaches to Modifying the Electronic Band Structure for Visible-Light Harvesting 6519

Semiconductor-based Photocatalytic Hydrogen Generation

This chapter describes recent progress on the development of rutile TiO2–based photocatalysts for visible light water splitting made by our group. Although rutile TiO2 is a wide-gap semiconductor with a band gap of 3.0 eV, we found that codoping of nitrogen and tantalum (or fluorine) into rutile TiO2 gives new absorption in visible light region, which is available for water oxidation reaction. Another effective means to activate the wide-gap TiO2 is surface modification with nanoparticulate cobalt hydroxide or oxide, which enables to utilize an entire range of visible light for water oxidation.

Rutile TiO2–based new photocatalysts for visible light water oxidation

Photocatalytic CO2 reduction is in high demand for sustainable energy management. Hybrid photocatalysts combining semiconductors with supramolecular photocatalysts represent a powerful strategy for constructing visible-light-driven CO2 reduction systems with strong oxidation power. Here, we demonstrate the novel effects of plasma surface modification of graphitic carbon nitride (C3N4), which is an organic semiconductor, to achieve better affinity and electron transfer at the interface of a hybrid photocatalyst consisting of C3N4 and a Ru(II)–Ru(II) binuclear complex (RuRu′). This plasma treatment enabled the “surface-specific” introduction of oxygen functional groups via the formation of a carbon layer, which worked as active sites for adsorbing metal-complex molecules with methyl phosphonic-acid anchoring groups onto the plasma-modified surface of C3N4. Upon photocatalytic CO2 reduction with the hybrid under visible-light irradiation, the plasma-surface-modified C3N4 with RuRu′ enhanced the durability of HCOOH production by three times compared to that achieved when using a nonmodified system. The high selectivity of HCOOH production against byproduct evolution (H2 and CO) was improved, and the turnover number of HCOOH production based on the RuRu′ used reached 50 000, which is the highest among the metal-complex/semiconductor hybrid systems reported thus far. The improved activity is mainly attributed to the promotion of electron transfer from C3N4 to RuRu′ under light irradiation via the accumulation of electrons trapped in deep defect sites on the plasma-modified surface of C3N4.

https://pubs.acs.org/doi/pdf/10.1021/acsami.3c00955

Surface-Specific Modification of Graphitic Carbon Nitride by Plasma for Enhanced Durability and Selectivity of Photocatalytic CO2 Reduction with a Supramolecular Photocatalyst

PURPOSE:To easily produce an alkoxynaphthalenecarboxylic acid by adding 1,3-butadiene to an alkoxyalXylbenzene using an alkali metal as a catalyst, cyclizing and dehydrogenating the addition reaction product and finally oxidizing the product CONSTITUTION:An alkoxyalkylnaphthalenecarboxylic acid is produced by carrying out addition reaction of an alkoxyalkylbenzene with 1,3-butadiene in the presence of a catalyst consisting of simple alkali metal, its alloy or an organometallic compound, cyclizing the addition product with an acid catalyst to obtain an alkoxyalkyltetralin, dehydrogenating the product to form an alkoxyalkylnaphthalene and finally oxidizing the alkoxyalkylnaphthalene to produce the objective alkoxyalkylnaphthalenecarboxylic acid Alkoxyalkylnaphthalenecarboxylic acid is useful as an intermediate raw material for pharmaceuticals, agrochemicals, resins, electronic materials, etc This process enables the production of an alkoxynaphthalenecarboxylic acid which is difficult to be synthesized by the Kolbe-Schmitt's reaction of naphthol

Production of alkoxynaphthalenecarboxylic acid

Reduction of CO 2 Using Photocatalysts and a Photoelectrochemical Cell Consisted of Metal Complexes and Semiconductors

Efficient Nonsacrifical Water Splitting Through Two-Step Photoexcitation by Visible Light Using a Modified Oxynitride as a Hydrogen Evolution Photocatalyst.

Kazuhiko Maeda

Papers

Rutile TiO2–based new photocatalysts for visible light water oxidation

Surface-Specific Modification of Graphitic Carbon Nitride by Plasma for Enhanced Durability and Selectivity of Photocatalytic CO2 Reduction with a Supramolecular Photocatalyst

Production of alkoxynaphthalenecarboxylic acid

Reduction of CO 2 Using Photocatalysts and a Photoelectrochemical Cell Consisted of Metal Complexes and Semiconductors

Efficient Nonsacrifical Water Splitting Through Two-Step Photoexcitation by Visible Light Using a Modified Oxynitride as a Hydrogen Evolution Photocatalyst.