| Cyanogels, a class of unique coordination hydrogels, are three-dimensional bimetallic inorganic polymers. The cyano-bridged coordination polymer gels can be conveniently formed through ligand-substitution reactions between aqueous solutions of metal chlorides and solution of transition-metal cyanometalates. The most difference among hydrogel is that metal species concentration on the backbone of three-dimensional network, rather than dispersed in the solution. The inorganic-organic cyanogel can be obtained by adding chitosan and ethylenediamine-tetramethylenephosphonic acid while we prepare the bare cyanogel.Furthermore, we can get the carbon-based hybrids using inorganic-organic cyanogel as precursor. The main contents are as follows:1. we have designed a novel inorganic-organic hybrid cyanogel-bridged approach for the facile synthesis of N-doped graphitic carbon nanosheet-immobilized highly dispersed PdP alloy nanoparticles. Due to the unique 2D sheet-like nanostructure and favorable synergistic effect between highly dispersed PdP nanoparticles and graphitic carbon support, the rate constant k in Pd-P@N-C nanosheet is calculated to be 0.344 min-1, which is 1.8 times and 3.9 times higher than that of commercial Pd/C (0.192 min-1) and Pd@N-C nanosheets (0.089 min-1), respectively. More importantly, it is anticipated that the feasible synthetic methodology presented here could inspire the future rational design of carbon-based nanohybrids with multiple functionalities.2. we propose a hybrid cyanogel-derived thermal-autoreduction route for the construction of 3D nanoporous networks of Sn-M-P ternary alloys immobilized within nitrogen/phosphorus-rich carbon matrices (Sn-M-P@N/P-C networks) using chitosan-polyphosphonate hybridized cyano-bridged coordination polymer hydrogels as precursors. The morphology and structure of the product are investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM),X-ray powder diffraction (XRD) and energy dispersive spectrum (EDS) etc. the as-constructed Sn-Ni-P@N/P-C network manifests ideal lithium-storage performance in terms of high reversible capacities and good capacity retention. there is no capacity fading for the Sn-Ni-P@N/P-C network after the initial 20 cycles, and the Sn-Ni-P@N/P-C network is thus able to deliver a high reversible capacity of 453.3 mA h g-1 in the 100th cycle, the reversible capacities vary along with discharging rates, and the average discharge capacities within 10 cycles change from 449.7 (100 mA g-1) to 358.0 (200 mA g-1), 287.5 (500 mA g-1), and 237.0 mA h g-1 (1A g-1), and finally reversibly back to 455.7 mA h g-1 (100 mA g-1). These results reveal the high rate capability of the Sn-Ni-P@N/P-C network and facilitate its application as a high-rate anode for advanced LIBs. the rationally designed Sn-M@C networks might demonstrate desirable lithium-storage performances by virtue of their structural and compositional characteristics.3. we have rationally designed and constructed a novel type of interior-confined immobilized within carbon/graphene dual matrices, Sn-Ni@C/G sheets, via a facile and scalable hybrid aerogel-derived thermal-autoreduction route. The morphology,structure and composition of the Sn-Ni@C/G sheets are investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD). When applied as a potential anode material in LIBs, the Sn-Ni@C/G sheets demonstrate good cycling stability, high reversible capacities and rate capability by virtue of its structural and compositional superiorities toward lithium storage. The desirable lithium storage performance of the Sn-Ni@C/G sheets makes it an ideal anodic candidate in advanced LIBs with long cycle life, high energy and power densities. a high reversible capacity of 503.0 mA h g-1 can be delivered after 100 cycles at a current density of 100 mA g-1, meanwhile,high current densities of 500 mA g-1 and 1 A g-1, respectively. Moreover, the proposed hybrid aerogel-derived thermal-autoreduction strategy might open up new opportunities for fabricating nanoporous networks of alloy components immobilized within carbon matrices as advanced anodes for LIBs. |
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