Electrochemically active hollow nanostructured materials hold great promise in diverse energy conversion and storage applications, however, intricate synthesis steps and poor control over compositions and morphologies have limited the realization of delicate hollow structures with advanced functional properties. In this study, we demonstrate a one-step wet-chemical strategy for co-engineering the hollow nanostructure and anion intercalation of nickel cobalt layered double hydroxide (NiCo-LDH) to attain highly electrochemical active energy conversion and storage functionalities. Self-templated pseudomorphic transformation of cobalt acetate hydroxide solid nanoprisms using nickel nitrate leads to the construction of well-defined NiCo-LDH hollow nanoprisms (HNPs) with multi-anion intercalation. The unique hierarchical nanosheet-assembled hollow structure and efficiently expanded interlayer spacing offer an increased surface area and exposure of active sites, reduced mass and charge transfer resistance, and enhanced stability of the materials. This leads to a significant improvement in the pseudocapacitive and electrocatalytic properties of NiCo-LDH HNP with respect to specific capacitance, rate and cycling performance, and OER overpotential, outperforming most of the recently reported NiCo-based materials. This work establishes the potential of manipulating sacrificial template transformation for the design and fabrication of novel classes of functional materials with well-defined nanostructures for electrochemical applications and beyond.

Novel hollow CeO 2 dodecahedrons were synthesized using ZIF-67 nanocrystals as templates via a one-step liquid phase reaction for the first time. The structure, composition, morphology, surface chemical states, and band gap of the as-prepared hollow CeO 2 dodecahedrons were thoroughly investigated with XRD, SEM, TEM, HR-TEM, XPS, Raman, UV-Vis and ICP-AES. The hollow structures, with a specific BET surface area as high as 128 m 2 g À1 , are composed of small CeO 2 nanocrystallites less than 5 nm. The formation mechanism of hollow CeO 2 dodecahedrons was proposed, and the relative rate between Ce 3+ hydrolysis and template dissolution was found to be the key to the successful formation of well-defined hollow dodecahedrons. The CO oxidation catalytic activities of hollow CeO 2 dodecahedrons revealed an excellent performance with a complete CO conversion at 170 C and a superior catalytic stability, which was attributed to the synergistic effect of large surface area, small crystallites, hollow structure, large amount of oxygen vacancies, and the containing Co species. This work provides a rapid and costefficient approach to synthesize a new dodecahedral CeO 2 hollow structure, which broadens the way to synthesize crystalline metal oxide with controllable morphologies in mild solution conditions.

This work demonstrates a facile in situ synthesis of cobalt-manganese mixed sulfide (CoMn-S) nanocages on reduced graphene oxide (RGO) sheets by using a crystalline Co-Mn precursor as the sacrificial template. The CoMn-S/RGO hybrid was applied as the anode for Li-ion storage and exhibited superior specific capacity, excellent cycling performance, and great rate capability. In particular, lithium storage testing revealed that the hybrid delivered high discharge-charge capacities of 670 mA h g at 1.0 A g after 400 cycles and 925 mA h g at 0.1 A g after 300 cycles. The outstanding electrochemical performance of CoMn-S/RGO is attributed to the close entanglement of nanocages with RGO nanosheets achieved by the synthetic method, which greatly improves ion/electron transport along the interfaces and efficiently mitigates volume dilation during lithium reactions. This rational design of both the composition and architecture of mixed metal sulfides can be expanded to other composite systems for high-capacity Li-ion batteries and provides a unique insight into the development of advanced hybrid electrode materials.

Electrochemically active hollow nanostructured materials hold great promise for diverse energy conversion and storage applications, however, intricate synthesis steps and poor control over compositions and morphologies have limited the realization of delicate hollow structures with advanced functional properties. In this study, a hollow nickel–cobalt layered double hydroxide nanostructure with multi‐anion intercalation was fabricated via a one‐step self‐template wet‐chemical method. The unique hierarchical nanosheet‐assembled hollow structure and efficiently expanded interlayer spacing offer increased exposure of active sites, reduced mass‐ and charge‐transfer resistance, and improved stability of materials, contributing to its excellent electrochemical performance as supercapacitor electrode material and oxygen evolution reaction (OER) electrocatalyst. More information can be found in the Full Paper by Cheng Li, Xiuling Jiao, Dairong Chen et al. on page 1129 in Issue 9, 2018 (DOI: 10.1002/asia.201800092).