Enhanced Sodium-Ion Mobility and Electronic Transport of Hydrogen-Incorporated V₂O₅ Electrode Materials

Although α-V₂O₅ as an attractive electrode material for electrochemical energy storage devices exhibits a high theoretical capacity, its atomic structure with the confined size of channels for Na-ion transport and low electronic conductivity lead to the poor rate performance. Here we demonstrate that hydrogen incorporation in α-V₂O₅ is an effective way to improve the kinetics of ionic and electronic transports by using the density functional theory. Among various structures of hydrogen-incorporated α-V₂O₅, H₂V₂O₅ presents enlarged diffusion channels along the [010] and [001] directions where the diffusion energy barriers decrease to 0.844 eV (−34.93%) and 1.737 eV (−41.81%), respectively. Improved electronic conductivity is also achieved for H₂V₂O₅ due to the insulator–metal transition attributed by the high concentration of hydrogen atoms. As H₂V₂O₅ has smaller volume expansion occurring during the Na-intercalation process, H₂V₂O₅ at the comparable specific capacity exhibits higher rate capability and cyclability than α-V₂O₅

Self-Grown Ni(OH)₂ Layer on Bimodal Nanoporous AuNi Alloys for Enhanced Electrocatalytic Activity and Stability

Au nanostructures as catalysts toward electrooxidation of small molecules generally suffer from ultralow surface adsorption capability and stability. Here, we report Ni­(OH)₂ layer decorated nanoporous (NP) AuNi alloys with a three-dimensional and bimodal porous architecture, which are facilely fabricated by a combination of chemical dealloying and in situ surface segregation, for the enhanced electrocatalytic performance in biosensors. As a result of the self-grown Ni­(OH)₂ on the AuNi alloys with a coherent interface, which not only enhances adsorption energy of Au and electron transfer of AuNi/Ni­(OH)₂ but also prohibits the surface diffusion of Au atoms, the NP composites are enlisted to exhibit significant enhancement in both electrocatalytic activity and stability toward glucose electrooxidation. The highly reliable glucose biosensing with exceptional reproducibility and selectivity as well as quick response makes it a promising candidate as electrode materials for the application in nonenzymatic glucose biosensors