Single crystals of T-Nb2O5 obtained by slow cooling method under high pressures

Facile formation of tetragonal-Nb2O5 microspheres for high-rate and stable lithium storage with high areal capacity

Niobium pentoxide (Nb₂O₅) has attracted great attention as an anode for lithium-ion battery, which is attributed to the high-rate and good stability performances. In this work, TT-, T-, M-, and H-Nb₂O₅ microspheres were synthesized by a facile one-step thermal oxidation method. Ion and electron transport properties of Nb₂O₅ with different phases were investigated by both electrochemical analyses and density functional theoretical calculations. Without nanostructuring and carbon modification, the tetragonal Nb₂O₅ (M-Nb₂O₅) displays preferable rate capability (121 mAh g^-1 at 5 A g^-1), enhanced reversible capacity (163 mAh g^-1 at 0.2 A g^-1) and better cycling stability (82.3% capacity retention after 1000 cycles) when compared with TT-, T-, and H-Nb₂O₅. Electrochemical analyses further reveal the diffusion-controlled Li⁺ intercalation kinetics and in-situ X-ray diffraction analysis indicates superior structural stability upon Li⁺ intercalation/deintercalation. Benefiting from the intrinsic fast ion/electron transport, a high areal capacity of 2.24 mAh cm^-2 is obtained even at an ultrahigh mass loading of 22.51 mg cm^-2. This work can promote the development of Nb₂O₅ materials for high areal capacity and stable lithium storage towards practical applications.

Multifunctional Nb–Cu nanostructured materials as potential adsorbents and oxidation catalysts for real wastewater decontamination

Hybrid oxidation catalysts and adsorbent materials containing niobium(v)–copper(ii) for the decontamination of real wastewater containing organic pollutants are reported herein.