Polymer semiconductors for artificial photosynthesis: hydrogen evolution by mesoporous graphitic carbon nitride with visible light.
21 Jan 2009-Journal of the American Chemical Society (American Chemical Society)-Vol. 131, Iss: 5, pp 1680-1681
TL;DR: It is shown that the efficiency of hydrogen production by photochemical water reduction can be improved by approximately 1 order of magnitude by introducing the right type of mesoporosity into polymeric C(3)N(4).
Abstract: We investigated semiconductor characteristics for polymeric carbon nitride as a metal-free photocatalyst working with visible light and have shown that the efficiency of hydrogen production by photochemical water reduction can be improved by ∼1 order of magnitude by introducing the right type of mesoporosity into polymeric C3N4. We anticipate a wide rang of potential application of C3N4 as energy transducers for artificial photosynthesis in general, especially with a 3D continuous nanoarchitecture. Moreover, the results of finding photoactivity for carbon nitride nanoparticles can enrich the discussion on prebiotic chemistry of the Earth, as HCN polymer clusters are unequivocal in the solar system.
Citations
More filters
TL;DR: Approaches to Modifying the Electronic Band Structure for Visible-Light Harvesting and its Applications d0 Metal Oxide Photocatalysts 6518 4.4.1.
Abstract: 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
6,332 citations
TL;DR: It is anticipated that this review can stimulate a new research doorway to facilitate the next generation of g-C3N4-based photocatalysts with ameliorated performances by harnessing the outstanding structural, electronic, and optical properties for the development of a sustainable future without environmental detriment.
Abstract: As a fascinating conjugated polymer, graphitic carbon nitride (g-C3N4) has become a new research hotspot and drawn broad interdisciplinary attention as a metal-free and visible-light-responsive photocatalyst in the arena of solar energy conversion and environmental remediation. This is due to its appealing electronic band structure, high physicochemical stability, and “earth-abundant” nature. This critical review summarizes a panorama of the latest progress related to the design and construction of pristine g-C3N4 and g-C3N4-based nanocomposites, including (1) nanoarchitecture design of bare g-C3N4, such as hard and soft templating approaches, supramolecular preorganization assembly, exfoliation, and template-free synthesis routes, (2) functionalization of g-C3N4 at an atomic level (elemental doping) and molecular level (copolymerization), and (3) modification of g-C3N4 with well-matched energy levels of another semiconductor or a metal as a cocatalyst to form heterojunction nanostructures. The constructi...
5,054 citations
TL;DR: The design and fabrication of a metal-free carbon nanodot–carbon nitride (C3N4) nanocomposite is reported and its impressive performance for photocatalytic solar water splitting is demonstrated.
Abstract: The use of solar energy to produce molecular hydrogen and oxygen (H2 and O2) from overall water splitting is a promising means of renewable energy storage. In the past 40 years, various inorganic and organic systems have been developed as photocatalysts for water splitting driven by visible light. These photocatalysts, however, still suffer from low quantum efficiency and/or poor stability. We report the design and fabrication of a metal-free carbon nanodot-carbon nitride (C3N4) nanocomposite and demonstrate its impressive performance for photocatalytic solar water splitting. We measured quantum efficiencies of 16% for wavelength λ = 420 ± 20 nanometers, 6.29% for λ = 580 ± 15 nanometers, and 4.42% for λ = 600 ± 10 nanometers, and determined an overall solar energy conversion efficiency of 2.0%. The catalyst comprises low-cost, Earth-abundant, environmentally friendly materials and shows excellent stability.
3,553 citations
TL;DR: In this article, a top-down thermal oxidation etching of bulk g-C3N4 in air has been shown to improve the photocatalytic activities of the material in terms of OH radical generation and hydrogen evolution.
Abstract: Graphitic (g)-C3N4 with a layered structure has the potential of forming graphene-like nanosheets with unusual physicochemical properties due to weak van der Waals forces between layers. Herein is shown that g-C3N4 nanosheets with a thickness of around 2 nm can be easily obtained by a simple top-down strategy, namely, thermal oxidation etching of bulk g-C3N4 in air. Compared to the bulk g-C3N4, the highly anisotropic 2D-nanosheets possess a high specific surface area of 306 m2 g-1, a larger bandgap (by 0.2 eV), improved electron transport ability along the in-plane direction, and increased lifetime of photoexcited charge carriers because of the quantum confinement effect. As a consequence, the photocatalytic activities of g-C3N4 nanosheets have been remarkably improved in terms of OH radical generation and photocatalytic hydrogen evolution.
2,900 citations
TL;DR: The photo-catalytic applications of g-C3N4 -based photocatalysts in the fields of water splitting, CO2 reduction, pollutant degradation, organic syntheses, and bacterial disinfection are reviewed, with emphasis on photocatalysis promoted by carbon materials, non-noble-metal coc atalysts, and Z-scheme heterojunctions.
Abstract: Semiconductor-based photocatalysis is considered to be an attractive way for solving the worldwide energy shortage and environmental pollution issues. Since the pioneering work in 2009 on graphitic carbon nitride (g-C3N4) for visible-light photocatalytic water splitting, g-C3N4 -based photocatalysis has become a very hot research topic. This review summarizes the recent progress regarding the design and preparation of g-C3N4 -based photocatalysts, including the fabrication and nanostructure design of pristine g-C3N4 , bandgap engineering through atomic-level doping and molecular-level modification, and the preparation of g-C3N4 -based semiconductor composites. Also, the photo-catalytic applications of g-C3N4 -based photocatalysts in the fields of water splitting, CO2 reduction, pollutant degradation, organic syntheses, and bacterial disinfection are reviewed, with emphasis on photocatalysis promoted by carbon materials, non-noble-metal cocatalysts, and Z-scheme heterojunctions. Finally, the concluding remarks are presented and some perspectives regarding the future development of g-C3N4 -based photocatalysts are highlighted.
2,868 citations
References
More filters
TL;DR: It is shown that an abundant material, polymeric carbon nitride, can produce hydrogen from water under visible-light irradiation in the presence of a sacrificial donor.
Abstract: 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.
9,751 citations
Journal Article•
TL;DR: In this paper, the authors look into the historical background, and present status and development prospects for photoelectrochemical cells, based on nanocrystalline materials and conducting polymer films.
Abstract: Until now, photovoltaics - the conversion of sunlight to electrical power - has been dominated by solid-state junction devices, often made of silicon. But this dominance is now being challenged by the emergence of a new generation of photovoltaic cells, based, for example, on nanocrystalline materials and conducting polymer films. These offer the prospect of cheap fabrication together with other attractive features, such as flexibility. The phenomenal recent progress in fabricating and characterizing nanocrystalline materials has opened up whole new vistas of opportunity. Contrary to expectation, some of the new devices have strikingly high conversion efficiencies, which compete with those of conventional devices. Here I look into the historical background, and present status and development prospects for this new generation of photoelectrochemical cells.
8,305 citations
TL;DR: The empirical model indicates that hypothetical covalent solids formed between carbon and nitrogen are good candidates for extreme hardness and first principles pseudopotential total energy calculation on the system shows that materials like the prototype can have bulk moduli comparable to or greater than diamond.
Abstract: An empirical model and an ab initio calculation of the bulk moduli for covalent solids are used to suggest possible new hard materials. The empirical model indicates that hypothetical covalent solids formed between carbon and nitrogen are good candidates for extreme hardness. A prototype system is chosen and a first principles pseudopotential total energy calculation on the system is performed. The results are consistent with the empirical model and show that materials like the prototype can have bulk moduli comparable to or greater than diamond. It may be possible to synthesize such materials in the laboratory.
2,364 citations
TL;DR: Direct water electrolysis was achieved with a novel, integrated, monolithic photoelectrochemical-photovoltaic design that splits water directly upon illumination; light is the only energy input.
Abstract: Direct water electrolysis was achieved with a novel, integrated, monolithic photoelectrochemical-photovoltaic design. This photoelectrochemical cell, which is voltage biased with an integrated photovoltaic device, splits water directly upon illumination; light is the only energy input. The hydrogen production efficiency of this system, based on the short-circuit current and the lower heating value of hydrogen, is 12.4 percent.
2,052 citations
TL;DR: A review of the known inorganic catalysts with a focus on structure-activity relationships is given in this article, where the first water splitting system based on TiO2 and Pt was proposed by Fujishima and Honda in 1972.
Abstract: Photochemical splitting of water into H2 and O2 using solar energy is a process of great economic and environmental interest. Since the discovery of the first water splitting system based on TiO2 and Pt in 1972 by Fujishima and Honda, over 130 inorganic materials have been discovered as catalysts for this reaction. This review discusses the known inorganic catalysts with a focus on structure–activity relationships.
1,977 citations