Hydrogen isotope permeation through structural materials is a key issue for developing nuclear fusion energy, which will cause fuel loss and radioactive pollution. Developing ceramic coatings with high thermal shock and hydrogen resistance is an effective strategy to solve this issue. In this work, a layer-structured Cr/Cr_xN coating was successfully fabricated by a facile electroplating-based nitridation technique, which is easy, facile, and applicable to coating complex-shaped substrates. The Cr/Cr_xN coating, composed of a bottom Fe/Cr interdiffusion zone, a middle Cr layer, and a top Cr_xN layer, exhibits high bonding strength, high anti-thermal-shock ability, and high deuterium permeation resistance. Its bonding strength achieves 43.6 MPa. The Cr/Cr_xN coating remains intact even after suffering 300 thermal shock cycles under a 600 ℃–water condition. Through optimizing the nitridation temperature, the Cr/Cr_xN coating achieves a deuterium permeation reduction factor (PRF) as high as 3599 at 500 ℃. Considering its scalable fabrication technique and considerable properties, the developed Cr/Cr_xN coating may serve as a novel high-performance hydrogen permeation barrier in various fields.

To promote the energy density of symmetric all-solid-state supercapacitors (SCs), efforts have been dedicated to searching for high-performance electrode materials recently. In this paper, vanadium nitride (VN) nanofibers with mesoporous structure have been fabricated by a facile electrospinning method. Their crystal structures and morphology features were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The mesoporous structure of VN nanofibers, which can provide short electrolyte diffusion routes and conducting electron transport pathways, is beneficial to their performance as a supercapacitor electrode. Under a stable electrochemical window of 1.0 V, VN nanofibers possess an excellent mass specific capacitance of 110.8 F/g at a scan rate of 5 mV/s. Moreover, the VN nanofibers were further assembled into symmetric all-solid-state SCs, achieving a high energy density of 0.89 mW·h/cm³ and a high power density of 0.016 W/cm³ over an operating potential range from 0 to 1.0 V. These results demonstrate that VN nanofibers could be potentially used for energy storage devices.