Great efforts on metal−organic framework (MOF) derived nanostructures have been devoted to modulating the compositional and structural complexities to enhance performance in various applications. However, a facile method that can simultaneously manipulate the structures of the MOF-derived material and the chemical component remains a considerable challenge. Here we report a facile strategy to use the polyhedral ZIF-8 as a precursor for synthesizing ZIF-8-derived hybrids with different components and morphologies. The synthesis involves the preparation of ZIF-8 MOF templates and sequential covering of the ZIF-8 with a interlayer of silica and then polydopamine-Ni 2+ (PDA-Ni 2+ ) and carbonizing at different high temperatures under a nitrogen atmosphere, finally leading to ZIF-8-derived hybrids with different components and structures. In the whole process, the preliminary ZIF-8 precursor play a crucial role in the morphology and structure of the final carbonized products, which can be considered as templates for silica coating and precursors of N-doped carbon layer and Zn species. We also found that the SiO 2 interlayer coating is a crucial procedure for the formation of yolk−shell structured ZIF-8@SiO 2 @PDA-Ni 2+ composites. Owing to the uniformly distributed Ni NPs and unique structures of the composites, the as-prepared Ni-based composites show high performance in the catalysis of 4-nitrophenol as well as enrichment of histidine-rich proteins. In addition, this proposed strategy for the controllable design and synthesis of ZIF-8-derived nanocomposites paves a new way in developing superior active materials in energy storage conversion etc.

In this paper, an extended Stöber method has been developed to fabricate a Ni-polydopamine (PDA) complex coated on Co[Co(CN)]@SiO composites. After one-step carbonization involving the heat treatment of a Prussian blue analogue (PBA) of Co[Co(CN)] cores and the PDA-Ni shell under a nitrogen atmosphere, homogeneous Co@SiO@C/Ni submicrorattles were synthesized. Notably, the silica interlayer played a vital role in the formation of such Co@SiO@C/Ni submicrorattle structures. Without the protection of SiO, Co-Ni@C composites were obtained instead and aggregated seriously due to sintering at high temperature. While with the silica layer as the spacer, the obtained Co@SiO@C/Ni composites were not only well dispersed in the solution, but could also be adjusted in terms of the size and density of Ni nanoparticles (NPs) on the surface. Moreover, the size of core Co and surficial Ni NPs can be facilely modulated via changing the calcination temperature, which can effectively control the catalytic performance of the as-prepared nanocomposites. The as-prepared Co@SiO@C/Ni submicrorattles were employed as the reaction catalyst for the reduction of 4-nitrophenol (4-NP), and exhibit both superior catalytic activity and cycling stability to Co@SiO and Co-Ni@C composites.

In this paper, we present a novel multifunctional magnetic composite with sandwich-like nanostructure, which is composed of a yolk-egg-like magnetic silica core and a continuous polydopamine(PDA)-Au coating. Firstly, yolk-egg-like magnetic composite(SiO 2 @Fe 3 O 4 @PDA) was prepared by a combined high temperature decomposition method with mussel chemistry.Then, Au nanoparticles(NPs) were in-situ generated on the surface of the SiO 2 @Fe 3 O 4 @PDA by reaction between the PDA shell and HAuCl 4 , forming a multilayer sandwich-like nanostructure.Benefiting from the good affinity of the PDA shell and Au NPs with thiol group, the 4-mercaptophenylboronic acid was successfully assembled on the surface of Au NPs and PDA layer. The hybrid magnetic composite functionalized with boronic acid was used as affinity probes to selectively capture PDGF from solution. Meanwhile, methylene blue(MB)-doped silica NPs (SiO 2 -MB) were prepared to immobilize aptamer. In the presence of PDGF, the aptamer labeled SiO 2 -MB (SiO 2 -MB-aptamer) specifically bound with the PDGF protein. By monitoring the change of the electrochemical signal of MB, we were able to detect the binding events between the aptamer and PDGF in homogeneous solutions. The sensor was highly selective and sensitive with a detection limit of 0.22 fM for PDGF. The developed method showed wide potential applications in protein monitoring and cancer diagnosis.

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An efficient electrooxidative double C-H/C-H coupling of phenols with 3-phenylbenzothiophene has been developed under external oxidant- and catalyst-free conditions. This strategy could enable the highly tunable access to benzothiophene derivatives...