Carbon hybrid with 3D nano-forest architecture in-situ catalytically constructed by CoFe alloy as advanced multifunctional electrocatalysts for Zn-air batteries-driven water splitting

Rational design and facile synthesis of non-noble materials as the effective multifunctional electrocatalysts are still challenging. Herein, a self-catalytically grafted growth approach is developed to construct carbon hybrid with three-dimensional(3 D) nano-forest architecture via controlled pyrolysis of metalpolymer nanofiber precursor and melamine. The metal-polymer nanofibers act as the matrix, and melamine is used as the initiator for orientated growth of one-dimensional(1 D) N-doped carbon nanotubes(N-CNTs) on carbon nanofibers. The as-prepared CoFe-N-CNTs/CNFs-900 possesses unique structure and component advantages in terms of 3 D structure, special synapse-like structure, porous feature,high-level N doping and bimetallic active components, which endow the material with structural stability, high mass/electron transport ability and large active sur-/interfaces. Benefiting from the integrated effects of all the above factors, CoFe-N-CNTs/CNFs were successfully applied to overall water splitting and Zn-air batteries. It is believed that this integrated design methodology can be extended to prepare other MàNàC materials for energy-related electrochemical reactions.

One-pot synthesis of MoSe2 hetero-dimensional hybrid self-assembled by nanodots and nanosheets for electrocatalytic hydrogen evolution and photothermal therapy

We designed and prepared a hetero-dimensional hybrid （HDH） based on molybdenum selenide （MoSe2） nanodots （NDs） anchored in few-layer MoSe2 nanosheets （NSs） （MoSe2 HDH） via a one-pot hydrothermal process. The MoSe2 HDH exhibits excellent electrocatalytic activity toward hydrogen evolution reaction （HER）. This is because, on the one hand, the edge-abundant features of MoSe2 NDs and the unique defect-rich structure at the interface of MoSe2 NSs/NDs could bring in more active sites for HER; on the other hand, the random stacking of the flake-like MoSe2 NSs on the surface of the supporting electrode may achieve efficient charge transport. Additionally, the MoSe2 HDH shows good water stability, desirable biocompatibility, and high near infrared （NIR） photothermal conversion efficiency. Therefore, the MoSe2 HDH is investigated as a nanomedicine in NIR photothermal therapy （PTT） for cancer. Specifically, the MoSe2 HDH can be applied as a dual-modal probe for computed tomography （CT） and photoacoustic tomography （PA） imaging owing to its strong X-ray attenuation ability and NIR absorption. Therefore, the MoSe2 HDH, combining PTT with CT/PA imaging into one system, holds great potential for imaging-guided cancer theranostics. This work may provide an ingenious strategy to prepare other hetero-dimensional layered transition metal dichalcogenides.

Covalent interfacial coupling of vanadium nitride with nitrogen-rich carbon textile boosting its lithium storage performance as binder-free anode

Eliminating the usage of metal current collectors and binders in traditional battery electrode configuration is an effective strategy to significantly improve the capacities of lithium ion batteries (LIBs). Herein, we demonstrate the construction of porous vanadium nitride (VN) nanosheet network in situ grown on nitrogen-rich (N-rich) carbon textile (N-C@P-VN) as lightweight and binder-free anode for LIBs. The N-rich carbon textile is used both as the current collector and host to store Li^(+), thus improving the specific capacities of binder-free VN anode and meanwhile reducing the inert mass of the whole cell. Moreover, the open spaces in carbon textile and vertically aligned pores in VN nanosheet network can not only provide an expressway for Li+ and e− transport, but also afford more active sites. As a result, the binder-free N-C@P-VN anode maintains a specific capacity of 1,040 mAh·g^(−1) (or an areal capacity of 2.6 mAh·cm^(−2)) after 100 cycles at 0.1 mA·cm^(−2) in half cell. Moreover, in an assembled N-C@P-VN//LiFePO4 full cell, it exhibits an areal capacity of 1.7 mAh·cm^(−2) after 300 cycles at 0.1 C. The synergistic strategy of N-C substrate and porous VN network could be applied to guide rational design of similar N-C@nitride or sulfide hybrid systems with corresponding sulfur-doped carbon textile as the substrate.