A novel ZnO hierarchical micro/nanoarchitecture is fabricated by a facile solvothermal approach in an aqueous solution of ethylenediamine (EDA). This complex architecture is of a core/shell structure, composed of dense nanosheet‐built networks that stand on a hexagonal‐pyramid‐like microcrystal (core part). The ZnO hexagonal micropyramid has external surfaces that consist of a basal plane (000${\bar 1}$) and lateral planes {0${\bar 1}$11}. The nanosheets are a uniform thickness of about 10 nm and have a single‐crystal structure with sheet‐planar surfaces as {2${\bar 1}\,{\bar 1}$0} planes. These nanosheets interlace and overlap each other with an angle of 60° or 120°, and assemble into a discernible net‐ or grid‐like morphology (about 100 nm in grid‐size) on the micropyramid, which shows a high specific surface area (185.6 m2 g−1). Such a ZnO micro/nanoarchitecture is new in the family of ZnO nanostructures. Its formation depends on the concentration of the EDA solution as well as on the type of zinc source. A two‐step sequential growth model is proposed based on observations from a time‐dependent morphology evolution process. Importantly, such structured ZnO has shown a strong structure‐induced enhancement of photocatalytic performance and has exhibited a much better photocatalytic property and durability for the photodegradation of methyl orange than that of other nanostructured ZnO, such as the powders of nanoparticles, nanosheets, and nanoneedles. This is mainly attributed to its higher surface‐to‐volume ratio and stability against aggregation. This work not only gives insight into understanding the hierarchical growth behaviour of complex ZnO micro/nanoarchitectures in a solution‐phase synthetic system, but also provides an efficient route to enhance the photocatalytic performance of ZnO, which could also be extended to other catalysts, such as the inherently excellent TiO2, if they are of the same hierarchical micro/nanoarchitecture with an open and porous nanostructured surface layer.

Nanoparticles coated with DNA molecules can be programmed to self-assemble into three-dimensional superlattices. Such superlattices can be made from nanoparticles with different functionalities and could potentially exploit the synergetic properties of the nanoscale components. However, the approach has so far been used primarily with single-component systems. Here, we report a general strategy for the creation of heterogeneous nanoparticle superlattices using DNA and carboxylic-based conjugation. We show that nanoparticles with all major types of functionality--plasmonic (gold), magnetic (Fe2O3), catalytic (palladium) and luminescent (CdSe/Te@ZnS and CdSe@ZnS)--can be incorporated into binary systems in a rational manner. We also examine the effect of nanoparticle characteristics (including size, shape, number of DNA per particle and DNA flexibility) on the phase behaviour of the heterosystems, and demonstrate that the assembled materials can have novel optical and field-responsive properties.

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Advances in self-assembly over the last decade have demonstrated that nano-and microscale particles can be organized into a large diversity of ordered three-dimensional (3D) lattices. However, the ability to generate the desired lattice type from the same set of particles remains challenging. Here, we show that nanoparticles can be assembled into crystalline and open 3D frameworks by connecting them through designed DNA-based polyhedral frames. The welldefined geometrical shapes of the frames, combined with the DNA-assisted binding properties of their vertices, facilitate the well-defined topological connections between particles in accordance with frame geometry. With this strategy, different crystallographic lattices using the same particles can be assembled by introduction of the corresponding DNA polyhedral frames. This approach should facilitate the rational assembly of nanoscale lattices through the design of the unit cell.The progress in nano-material fabrication methods was for long time motivated by the idea that self-assembly will endow us with ability to organize nanoparticles in the designed arrays. In reality, the particle characteristics have a profound effect on the assembled structure, thus, a little room is remaining for a structure architecting. Yet, it would be far more powerful to have an ability generating the different desired types of 3D lattices from the same particles. Such freedom of lattice engineering will permit fabricating targeted materials, which properties can be enhanced and manipulated by precise organization of functional components [1][2][3][4][5] .Colloids, often presented as a model of atomic systems, have revealed a great insight about the fundamentals of crystal formation [6][7][8][9] and the role of a particle nature [10][11][12] . Although an Reprints and permissions information is available online at www.nature.com/reprints. Supplementary information is available in the online version of the paper. Competing financial interestsThe authors declare no competing financial interests. HHS Public AccessAuthor manuscript Nat Mater. Author manuscript; available in PMC 2017 January 31. Author Manuscript Author ManuscriptAuthor Manuscript Author Manuscript extremely rich variety of lattices have been demonstrated 12-15 , the particular particle characteristics-such as sizes 13,16,17 , interactions, entropic and many-body effects 18-21 , and shape 22-24 -dominate lattice formation. These dependencies are both natural and useful; numerous investigations have detailed how particle characteristics drive structure formation 12,[24][25][26][27][28] . While these studies uncovered a great depth of physical insight, the goal of lattice "engineering" remains elusive, due to the complex dependences between the structural and energetic parameters of particle and lattice, and the necessity to tailor particles for each target lattice.Anisotropic interparticle interactions, induced by precise arrangement of binding patches or by particle shaping, were considered as means to simplify ...