This cover was designed by Chenxiao Wang for an article published in J. Am. Chem. Soc. (2023, 145, pp. 2553-2560). It shows the synthesis of high-entropy alloy nanocubes with well-defined {100} facets. The synthesis involves the use of well-defined Rh cubic seeds, halide-free precursors, and a method for precisely controlling the reaction kinetics of different precursors. In the setting of dropwise addition, the precursors with different reactivities can be reduced at about the same pace for the generation of an alloy with a uniform and well-controlled composition. The core−shell nanocubes show greatly enhanced activity toward ethanol oxidation when benchmarked against Pd and Pt counterparts.
This cover was designed by Yifeng Shi for an article published in ChemNanoMat (2020, 6, pp. 386-393) on the synthesis of Pd-Cu twin cubes and right bipyramids. Using Pd nanoplates as the seeds, Pd‐Cu nanocrystals with planar defects are synthesized. The Cu atoms nucleate from one of the two basal faces on the Pd nanoplates in an asymmetric pattern due to the large lattice mismatch between the two metals. The planar defects are transferred into the Cu lattice. With the use of hexadecylamine and Cl− as the capping agents for Cu{100}, the final Cu‐Pd nanocrystals take a cubic shape in the case of hexagonal seeds with an even number of planar defects, whereas triangular seeds with a single planar defect leads to the formation of right bipyramids.
This cover was co-designed with Prof. Hong Yang at UIUC for a special issue on Nanoparticles for Catalysis in Accounts of Chemical Research (2013, vol. 46). The special issue is co-edited by Prof. Younan Xia, Prof. Hong Yang and Prof. Charles T. Campbell (University of Washington, Seattle). The last decade has witnessed an explosion in the development of new methods capable of generating metal nanoparticles with controlled compositions, sizes, shapes, and structures in an effort to control the ways in which these nanoparticles can be connected to and even surrounded by support materials like oxides. These nanostructured materials form the basis for many catalysts and electrocatalysts of great importance to future technologies including energy harvesting/conversion/storage, chemical transformation, and environmental protection.
This cover was designed by Dr. Ping Lu for an article published in Langmuir (2013, 29, pp. 7070-7078). It shows a scanning electron micrograph of a polystyrene (PS) yarn consisting of multiple nanoscale fibrils. The PS yarns could be readily fabricated by controlling the humidity of the environment used for electrospinning. Depending on the miscibility between the solvent and water vapor, the PS jet could be directed to generate parallel arrays of fibrils with diameters below 100 nm.
This cover was designed by Benjamin Wiley (Ph.D., 2006) for a feature article published in the Journal of Physical Chemistry B (2006, 110, pp. 15666-15675). It shows the formation of silver nanocubes, pentagonal nanowires, and right bipyramids from atoms through three different types of seeds: single-crystal cubooctahedron, multiply twinned decahedron with a five-fold axis, and singly twinned, respectively. Such a shape control enables one to maneuver the optical (plasmonic) properties of silver nanocrystals.
This cover was designed by Yiqun Zheng (Ph.D., 2013) for an article published in Chemistry: An Asian Journal (2013, 8, pp.792-799). It shows transmission electron micrographs of Au nanospheres 10 nm in diameter (upper left) and the wavy nanowires (lower right) formed upon dilution of the nanospheres with deionized water. The image in between provides a high-resolution transmission electron micrograph of the wavy nanowire, clearly showing the grain boundary between adjacent nanospheres.
This cover was designed by Dr. Yu Zhang (Ph.D. 2013) for an invited essay (Are We Entering the Nano Era? by Y. Xia, pp. 12268-12771) and an invited review article (Engineered Nanoparticles for Drug Delivery in Cancer Therapy by T. Sun, Y. S. Zhang, B. Pang, D. C. Hyun, M. Yang and Y. Xia, pp.12320-12364) published in Angewandte Chemie International Edition (2014, vol. 53), a special issue on nanotechnology, nanomaterials, nanotoxicology and nanomedicine. It shows that nanomaterials is a double-side sword: although the potential of nanotechnology is tremendous, questions remain about the long-term safety of nanomaterials and the risk-benefit characteristics of their usage.
This inside cover was designed by Wenying Liu (Ph.D., 2014) for a review article published in Advanced Healthcare Materials (2012, 1, pp. 10-25). It shows a scanning electron micrograph of a uniaxially aligned array of electrospun nanofibers in the background. When fabricated from FDA-approved biodegrdable polymers, such aligned nanofibers could serve as scaffolds for a range of applications in tissue engineering and regenerative medicine, including peripheral nerve and tendon-to-bone insertion repair.
This cover was designed by Yu Zhang (Ph.D., 2013) for an article published in Macromolecular Rapid Communications (2012, 33, pp. 296-301). It shows scanning electron microscopy (SEM) images (left panels) of inverse opal scaffolds after their pores had been modified with chitosan microstructures. As a result, cells cultured in the pores of the scaffolds would experience a truly three-dimensional environment. In comparison, cells cultured in scaffolds without the modification would experience a two-dimensional environment, as indicated by the fluorescence micrographs on the right side.
This cover was designed by Shuifen Xie (a visiting Ph.D. student in the Xia from Xiamen University) for an article published in Chemistry: A European Journal (2012, 18, pp.14974-14980). It shows transmission electron micrographs of Au-Cu nanocages of 50 nm in diameter with Pd cubic cores in the center. This novel nanostructures were synthesized via galvanic replacement reaction between Pd@Cu nanocubes with an aqueous HAuCl4 solution. While the Cu was oxidized, the released electrons were used to reduce Au precursor in Au atoms to be deposited around the template.
This cover was designed by Dr. Jie Zeng for an article published in ChemCatChem (2012, 4, pp. 1668-1674). It shows the formation of Pd-Au bimetallic nanocrystals with different shapes and structures, including Pd-Au dimeric structures, Pd-Au core-shell nanocubes, and Pd-Au concave nanocubes. The key is to control the reaction kinetics for the Au precursor, which was introduced into an suspension of seeds made of Pd nanocubes. Such bimetallic nanocrystals with well-defined facets are useful in catalysis.
This inside cover was designed by Professor Hui Zhang (a former visiting scholar in the Xia group from Zhejiang University) for a review article published in Angewandte Chemie International Edition (2012, 51, pp.7656-7673 ) on the design, synthesis, properties, and unique applications of noble-metal nanocrystals with concave surfaces. Due to the presence of high-index facets on the surface, concave nanocrystals are interesting and important as a novel class of catalysts with substantially improved activity.
