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Innovations in computational nanoscience have traditionally come in conjunction with experimental innovations, but uncertainty often surrounds the trustworthiness of in silico studies. While the accuracy of simulations has been improving every year, considerably less attention has focused on dealing with increasing complexity, which may be the source of concern. Creating more realistic virtual experiments (without sacrificing theoretical and numerical accuracy) remains challenging, particularly when we are confronted with the polydispersivity characteristic of extra silico samples. Fortunately, there are various theoretical methods that can be used in conjunction with first-principles simulations, not the least of which are the statistical tools and techniques promised by the emerging fields of materials informatics and data-driven sciences.

Molecular doping and detection are at the forefront of graphene research, a topic of great interest in physical and materials science. Molecules adsorb strongly on graphene, leading to a change in electrical conductivity at room temperature. However, a common impediment for practical applications reported by all studies to date is the excessively slow rate of desorption of important reactive gases such as ammonia and nitrogen dioxide. Annealing at high temperatures, or exposure to strong ultraviolet light under vacuum, is employed to facilitate desorption of these gases. In this article, the molecules adsorbed on graphene nanoflakes and on chemically derived graphene-nanomesh flakes are displaced rapidly at room temperature in air by the use of gaseous polar molecules such as water and ethanol. The mechanism for desorption is proposed to arise from the electrostatic forces exerted by the polar molecules, which decouples the overlap between substrate defect states, molecule states, and graphene states near the Fermi level. Using chemiresistors prepared from water-based dispersions of single-layer graphene on mesoporous alumina membranes, the study further shows that the edges of the graphene flakes (showing p-type responses to NO₂ and NH₃) and the edges of graphene nanomesh structures (showing n-type responses to NO₂ and NH₃) have enhanced sensitivity. The measured responses towards gases are comparable to or better than those which have been obtained using devices that are more sophisticated. The higher sensitivity and rapid regeneration of the sensor at room temperature provides a clear advancement towards practical molecule detection using graphene-based materials., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

For the move from nanoscience to nanotechnology to be sustainable, it is important that the issues surrounding possible 'nano-hazards' be addressed before commercialization. The global push for more environmentally friendly, biodegradable products, means the introduction of the nanoparticles contained within these products into the ecosystem is an inevitability. When this happens, it is desirable to know how the hazardous properties may be affected, and what the potential hazards are. In this article, a number of strategies will be discussed, combining the desirable aspects of theory, simulation, experiment and observation, and leading to predictions for incorporation into preventative frameworks. Particular attention will be given to the role of theory and computation, and how it intersects with the participants from complementary fields.

Discussions of the potential risks and hazards associated with nanomaterials and nanoparticles tend to focus on the need for further experiments. However, theoretical and computational nanoscientists could also contribute by making their calculations more relevant to research into this area.

The incorporation of more experimentally relevant parameters into theoretical descriptions of nanomaterials is important for our understanding of the stability of nanostructures in different chemical environments. Using a size-, shape-, and temperature-dependent thermodynamic model we have generated the first phase map for anatase and rutile nanocrystals, that includes both the equilibrium shape and the affects of surface chemistry. The calculated phase map indicates that the equilibrium boundary between anatase and rutile nanocrystals is surface charge chemistry dependent, which relates to both their formation and postsynthesis environments.

The development of interpretable structure/property relationships is a cornerstone of nanoscience, but can be challenging when the structural diversity and complexity exceeds our ability to characterise it. This is often the case for imperfect, disordered and amorphous nanoparticles, where even the nomenclature can be unspecific. Disordered platinum nanoparticles have exhibited superior performance for some reactions, which makes a systematic way of describing them highly desirable. In this study we have used a diverse set of disorder platinum nanoparticles and machine learning to identify the pure and representative structures based on their similarity in 121 dimensions. We identify two prototypes that are representative of separable classes, and seven archetypes that are the pure structures on the convex hull with which all other possibilities can be described. Together these nine nanoparticles can explain all of the variance in the set, and can be described as either single crystal, twinned, spherical or branched; with or without roughened surfaces. This forms a robust sub-set of platinum nanoparticle upon which to base further work, and provides a theoretical basis for discussing structure/property relationships of platinum nanoparticles that are not geometrically ideal. [ABSTRACT FROM AUTHOR]

The structure of carbon based nano-scale materials is extremely diverse at the molecular level and is very important in determining the properties and potential uses of these materials. Ab initio quantum mechanical methods have proved to be successful in giving insight into this structure. This is especially so, for nano-diamond clusters, -wires and -tubes. Here, we apply ab initio DFT based simulations to study some aspects of the structure and properties of graphene layers and graphene tubes to compare and contrast some of their properties such as energy, interconversion and X-ray spectra. [ABSTRACT FROM AUTHOR]

We are entering the next generation of the nano-age, where nanoscience is turning into nanotechnology. [Copyright &y& Elsevier]