Although gold is the subject of one of the most ancient themes of investigation in science, its renaissance now leads to an exponentially increasing number of publications, especially in the context of emerging nanoscience and nanotechnology with nanoparticles and self-assembled monolayers (SAMs). We will limit the present review to gold nanoparticles (AuNPs), also called gold colloids. AuNPs are the most stable metal nanoparticles, and they present fascinating aspects such as their assembly of multiple types involving materials science, the behavior of the individual particles, size-related electronic, magnetic and optical properties (quantum size effect), and their applications to catalysis and biology. Their promises are in these fields as well as in the bottom-up approach of nanotechnology, and they will be key materials and building block in the 21st century. Whereas the extraction of gold started in the 5th millennium B.C. near Varna (Bulgaria) and reached 10 tons per year in Egypt around 1200-1300 B.C. when the marvelous statue of Touthankamon was constructed, it is probable that “soluble” gold appeared around the 5th or 4th century B.C. in Egypt and China. In antiquity, materials were used in an ecological sense for both aesthetic and curative purposes. Colloidal gold was used to make ruby glass 293 Chem. Rev. 2004, 104, 293−346

Gold nanoparticles: assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology.

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...

Graphitic Carbon Nitride (g-C3N4)-Based Photocatalysts for Artificial Photosynthesis and Environmental Remediation: Are We a Step Closer To Achieving Sustainability?

A review on g-C3N4-based photocatalysts

A surface science perspective on TiO2 photocatalysis

Polyoxometalates (POMs) are discrete anionic metaloxygen clusters which can be regarded as soluble oxide fragments. They exhibit a great diversity of sizes, nuclearities, and shapes. They are built from the connection of {MOx} polyhedra, M being a d-block element in high oxidation state, usually VIV,V, MoVI, or WVI.1 While these species have been known for almost two centuries, they still attract much interest partly based on their large domains of applications. They play a great role in various areas ranging from catalysis,2 medicine,3 electrochemistry,4 photochromism,5 to magnetism.6 This palette of applications is intrinsically due to the combination of their added value properties (redox properties, large sizes, high negative charges, nucleophilicity...). Parallel to this domain, the organic-inorganic hybrids area has followed a similar expansion during the last 10 years. The concept of organic-inorganic hybrid materials * To whom correspondence should be addressed. E-mail: dolbecq@ chimie.uvsq.fr. Chem. Rev. 2010, 110, 6009–6048 6009

Hybrid Organic−Inorganic Polyoxometalate Compounds: From Structural Diversity to Applications

Almost four decades since its existence was first proposed, a fourth basic circuit element joins the canonical three. The 'memristor' might herald a step-change in the march towards ever more powerful circuitry.

Electronics: the fourth element.

http://nathan.instras.com/ResearchProposalDB/doc-131.pdf

Photochromism in composite and hybrid materials based on transition-metal oxides and polyoxometalates

Different composite films prepared by coupling ZnO and nitrogen-doped ZnO (N-ZnO) were used to photodegrade humic acids (HA). The catalysts exhibit an activity in the order of glass/ZnO/N-ZnO > gla...

Photocatalytic activity of heterostructures based on ZnO and N-doped ZnO.

Molybdenum oxide can exhibit pronounced photochromism and thus might act as an excellent photonic material for a number of technical applications. In the early stage of the research, the attention was focused mainly on the (band) structure, photochromic mechanism and the behavior of the oxide. Later, many investigations were carried out on the factors that might influence the photochromic performance. At the same time, the photochromic response has been extended from UV light to visible light. In this review, the progress in all of these areas will be reviewed thoroughly.

Photochromism of molybdenum oxide

Tungsten oxide exhibits pronounced photochromism upon bandgap photoexcitation, which makes it attractive and promising for applications in many areas. Some advances have been achieved during the past decades. The research on nanocrystalline films and single crystals indicates the critical importance of defects in tungsten oxide to its photochromism. Based on energy-band engineering of semiconductors, enhancement of photochromism has been achieved, for instance, extension of the photoresponse from UV to visible light by cathodic polarization, improved change in absorption before and after coloration through modification by a noble metal or another metal-oxide semiconductor, and increased photochromic reversibility via hybridization with organic amines. Nanocrystalline oxide films exhibit controllable wettability, which is coherent in nature with photochromism.

Tao He

Papers

Electronics: the fourth element.

Photochromism in composite and hybrid materials based on transition-metal oxides and polyoxometalates

Photocatalytic activity of heterostructures based on ZnO and N-doped ZnO.

Photochromism of molybdenum oxide

Photochromic materials based on tungsten oxide