Institute of Inorganic Chemistry, University of Cologne , Greinstraße 6, 50939, Cologne, Germany.
Departamento Fisica de la Materia Condensada-ICMS ( Universidad de Sevilla-CSIC ), Avda Reina Mercedes s/n, 41012 Seville, Spain.
ACS Appl Mater Interfaces. 2016 Aug 24;8(33):21423-30. doi: 10.1021/acsami.6b03945. Epub 2016 Aug 9.
We report here on the controlled synthesis, characterization, and electrochemical properties of different polymorphs of niobium pentoxide grown by CVD of new single-source precursors. Nb2O5 films deposited at different temperatures showed systematic phase evolution from low-temperature tetragonal (TT-Nb2O5, T-Nb2O5) to high temperature monoclinic modifications (H-Nb2O5). Optimization of the precursor flux and substrate temperature enabled phase-selective growth of Nb2O5 nanorods and films on conductive mesoporous biomorphic carbon matrices (BioC). Nb2O5 thin films deposited on monolithic BioC scaffolds produced composite materials integrating the high surface area and conductivity of the carbonaceous matrix with the intrinsically high capacitance of nanostructured niobium oxide. Heterojunctions in Nb2O5/BioC composites were found to be beneficial in electrochemical capacitance. Electrochemical characterization of Nb2O5/BioC composites showed that small amounts of Nb2O5 (as low as 5%) in conjunction with BioCarbon resulted in a 7-fold increase in the electrode capacitance, from 15 to 104 F g(-1), while imparting good cycling stability, making these materials ideally suited for electrochemical energy storage applications.
我们在此报告了通过 CVD 使用新型单源前体制备不同多晶型氧化铌的可控合成、表征和电化学性能。在不同温度下沉积的 Nb2O5 薄膜表现出从低温四方相（TT-Nb2O5，T-Nb2O5）到高温单斜相（H-Nb2O5）的系统相演变。优化前驱体流量和衬底温度可以选择性地在导电介孔生物形态碳基质（BioC）上生长 Nb2O5 纳米棒和薄膜。在整体式 BioC 支架上沉积的 Nb2O5 薄膜产生了复合材料，将碳质基质的高表面积和导电性与纳米结构氧化铌的固有高电容结合在一起。在 Nb2O5/BioC 复合材料中发现的异质结有利于电化学电容。对 Nb2O5/BioC 复合材料的电化学表征表明，少量的 Nb2O5（低至 5%）与 BioCarbon 结合可使电极电容从 15 增加到 104 F g(-1)，同时赋予良好的循环稳定性，使这些材料非常适合电化学储能应用。
