Photocatalyst releasing hydrogen from water

Maeda, Kazuhiko; Teramura, Kentaro; Lu, Daling; Takata, Tsuyoshi; Saito, Nobuo; Inoue, Y.; Domen, Kazunari

doi:10.1038/440295a

Cited by 2,670 publications

(1,760 citation statements)

References 6 publications

Supporting

Mentioning

1,725

Contrasting

Unclassified

Order By: Relevance

“…Therefore, the main difference of PEC cells from photosynthetic systems is that the redox potential energy of the charge-separated state is not stored in products of subsequent reactions, rather it is used directly to produce a photocurrent. 143,144 High-temperature electrolysis (HTE), also known as steam electrolysis, is performed using a solid oxide electrolysis cell (SOEC), as shown in Figure 11. It adopts a solid oxide, as the electrolyte, in a process that is essentially the reverse operation of a solid oxide FC.…”

Section: Future Trendsmentioning

confidence: 99%

Hydrogen production by alkaline water electrolysis

Santos¹,

Sequeira²,

Figueiredo³

2013

Quím. Nova

347

218

View full text Add to dashboard Cite

Recebido em 13/12/12; aceito em 28/5/13; publicado na web em 17/7/13Water electrolysis is one of the simplest methods used for hydrogen production. It has the advantage of being able to produce hydrogen using only renewable energy. To expand the use of water electrolysis, it is mandatory to reduce energy consumption, cost, and maintenance of current electrolyzers, and, on the other hand, to increase their efficiency, durability, and safety. In this study, modern technologies for hydrogen production by water electrolysis have been investigated. In this article, the electrochemical fundamentals of alkaline water electrolysis are explained and the main process constraints (e.g., electrical, reaction, and transport) are analyzed. The historical background of water electrolysis is described, different technologies are compared, and main research needs for the development of water electrolysis technologies are discussed.

show abstract

Section: Future Trendsmentioning

confidence: 99%

Hydrogen production by alkaline water electrolysis

Santos¹,

Sequeira²,

Figueiredo³

2013

Quím. Nova

347

218

View full text Add to dashboard Cite

show abstract

“…Solar irradiation provides a clean and unlimited energy resource to address ener gy and environmental issues [1][2][3][4]. Photocatalytic water splitting achieved on semiconductor diodes is facile and sustainable to capture, convert and store solar photons in a chemical fashion.…”

Section: Introductionmentioning

confidence: 99%

Photocatalytic water oxidation by layered Co/h-BCN hybrids

et al. 2015

View full text Add to dashboard Cite

The search for new materials has progressed from metal-based photocatalysts to elemental semiconductors (C, Si, P, S, B) [11][12][13][14][15] and recently to metal-free binary materials and polymers, such as carbon nitride [16], boron carbide [17] and conjugated semiconductors [18][19][20]. These researches indicate that photon absorbing materials can be constituted by using lightweight elements such as carbon, nitrogen, and boron, opening up new opportunities for the selection of innovative and intriguing materials for artificial photosynthesis. It is of particular interest that some of these elements themselves (graphene [21], silicone [22]) or their combinations (h-BN, g-C 3 N 4 ) [23] can form layered structures with reduced thickness comparable to charge-diffusion distance, and thus if a semiconducting electronic structure was imparted in these materials, the fast separation of light-induced charge carrier would significantly benefit surface photoredox process that relied on the excitation and separation of electron-hole pairs and their subsequent participation in surface chemical reactions [24][25][26]. An interesting case of such a layered material is ternary h-BCN with tuneable ba nd gap energies between graphene (zero bandgap) and h-BN (bandgap = 5.6 eV) [27], which have the same atomic structure and share many similar properties. The hybridized phases of the two two-dimensional (2D) materials by atomic mixture of B, N, and C with broad composition ranges to create various layered semiconducting structures would produce new material functions complementary to graphene and h-BN, enabling a wide variety of electronic structures, applications and properties [28][29][30]. Such an emerging family of chemically inert and mechanically strong 2D materials practically allows the bandgap-engineered applications in heterogeneous photocatalysis by creating a medium-gap ternary semiconductor, in which the band gap, redox energy levels, p/n-type properties and surface acid-base chemistry can in principle be modulated by rational design and synthesis [31,32].A hexagonal boron carbon nitride (h-BCN) semiconductor was applied to intercalate cobalt ions to catalyze oxygen evolution reaction (OER) with light illumination, without using noble metals. The h-BCN with high specific surface area showed a strong chemical affinity towards metal ions due to the "lop-sided" densities characteristic of ionic B-N bonding, enabling the creation of metal/h-BCN hybrid layered structures with unique properties. As exemplified here by Co/h-BCN for water oxidation catalysis, after intercalating cobalt ions in the h-BCN host, the photocatalytic activity of the resultant layered hybrid is optimized due to their synergic catalysis that promotes charge separation and lowers reaction barriers. This finding promises a new nobel-metal-free nanocompsite using cost-acceptable and earth-abundant sust ances for photocatalytic OER, and enables the facile design of duel catalytic cascades by merging transition metal catalysis with h-BCN (photo)catalys...

show abstract

“…[6][7][8][9][10][11][12] A photoelectrochemical solar fuel cell device combines the functions of light harvesting, charge separation and catalysis. [13][14][15] In the last decade several systems have been proposed employing either metal oxide nanoparticles 8,[16][17][18][19][20][21][22][23][24] or molecular complexes 8,[25][26][27][28] as water oxidation catalyst (WOC). Furthermore, the coupling between the WOC, the chromophore and an electron accepting semiconductor into a photoanode has been achieved through co-absorption of both the catalyst and the chromophore 16,[29][30][31][32] or through dye-WOC supramolecular complexes.…”

Section: Introductionmentioning

confidence: 99%