This cover was designed by Siyu Zhou for an article published in Angew. Chem. Int. Ed. (2023, e202306906). When Pd icosahedral nanocrystals are exposed to N2H4, the H-saturated twin boundaries divide each particle into 20 smaller single-crystal units in which the formation of phase boundaries is no longer favored. As such, absorption of H atoms is dominated by the single-phase pathway and one can readily obtain PdHx with any x in the range of 0−0.7. This work also demonstrates that the H-absorption kinetics will be accelerated if there is a tensile strain in the nanocrystals due to the increase in lattice spacing. Besides the unique H-absorption behaviors, the PdHx (x = 0–0.7) icosahedral nanocrystals show remarkable thermal and catalytic stability toward the formic acid oxidation because of the decrease in chemical potential for H atoms in a Pd lattice under tensile strain.
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 Zhiheng Lyu (Ph.D., 2020) and Yuxin Shang for a review article published in Accounts of Materials Research (2022, 3, pp. 1137-1148). It shows the synthesis of Cu nanocrystals with diverse and controllable shapes for plasmonic and catalytic applications. The utilization of preformed seeds made of other noble metals such as Pd can greatly facilitate the shape-controlled synthesis while introducing new functionality and/or enhancing the merit of performance.
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 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 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 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 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 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 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. Xiaohu Xia for a feature article published in the Journal of Physical Chemistry C (2013, 116, pp. 21647-21656). It shows the formation of silver nanoscale cubes, octahedrons, concave cubes (octapods), and concave octahedrons by controlling the experimental conditions used for the growth of single-crystal cuboctahedral seeds (shown in the center). Such a capability allows one to engineer the plasmonic and catalytic properties of silver nanocrystals.
This backside cover was designed by Dr. Jie Zeng for a communication published in Angewandte Chemie International Edition (2012, 51, pp.2354-2358) on the synthesis of nanocrystals with reduced symmetry by controlling the reaction kinetics. When the injection and thus deposition rate of precursor was very slow, the atoms could only nucleate on one of the six side faces of a cubic seed. As the injection rate was increased, the nucleation and growth could start to occur on three adjacent and then all six side faces.