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.

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.

Rational design and simple synthesis of one-dimensional nanofibers with high specific surface areas and hierarchically porous structures are still challenging. In the present work, a novel strategy utilizing a thermally removable template was developed to synthesize hierarchically porous N-doped carbon nanofibers (HP-NCNFs) through the use of simple electrospinning technology coupled with subsequent pyrolysis. During the pyrolysis process, ZnO nanoparticles can be formed in situ and act as a thermally removable template due to their decomposition and sublimation under high-temperature conditions. The resulting HP-NCNFs have lengths of up to hundreds of micrometers with an average diameter of 300 nm and possess a hierarchically porous structure throughout. Such unique structures endow HP-NCNFs with a high specific surface area of up to 829.5 m²·g^–1, which is 2.6 times higher than that (323.2 m²·g^–1) of conventional N-doped carbon nanofibers (NCNFs). Compared with conventional NCNFs, the HP-NCNF catalyst exhibited greatly enhanced catalytic performance and improved kinetics for the oxygen reduction reaction (ORR) in alkaline media. Moreover, the HP-NCNFs even showed better stability and stronger methanol crossover effect tolerance than the commercial Pt-C catalyst. The optimized ORR performance can be attributed to the synergetic contribution of continuous and three-dimensional (3D) cross-linked structures, graphene-like structure on the edge of the HP-NCNFs, high specific surface area, and a hierarchically porous structure.