氧空位过渡金属氧化物/稀土二维复合材料的可控制备及电容特性

Two-dimensional transition metal oxides with oxygen vacancies (2D r-TMOs) as high-performance environmentally friendly supercapacitive materials have potential advantages in energy storage due to their unsusual structures and physicochemical properties. However, for the studied 2D r-TMOs, the insufficient thin thickness, extremely small interlayer distance and low conductivity lead to a low capacitive behavior of 2D r-TMOs. The combination of ultrathin 2D r-TMOs and rare earth oxides (REOs) with unique electronic structure can overcome these deficiencies and improve capacitive performance, which fills the research gap of the capacitive performance of 2D r-TMOs/REOs nanocomposites. The project design desires to improve capacitive performance of 2D r-TMOs by the intercalating REOs. Ultrathin 2D r-TMOs can be prepared by the chemical or electrochemical reduction of ultrathin 2D TMOs that obtained through hydrothermal and exfoliated binding method or salt and surfactant template method. And then intercalating REOs into ultrathin 2D r-TMOs is to fabricate 2D LTMDs/REOs nanocomposites by various techniques. Changing the proportion, size and structure of REOs and the degree of oxygen vacancy in nanocomposites adjust the interlayer distance, spatial configuration and electronic structure of 2D r-TMOs to achieve a high conductivity and high capacitive performance. Finally, using the optimal 2D r-TMOs/RE nanocomposites fabricate the high-performance supercapacitors and evaluate its potential application. Additionally, in order to make clear the reason about the capacitive improvement of nanocomposites, the relation between the surface/interface microscopic structures, interlayer distance, oxygen vacancy degree, compositions, conductivity and properties of 2D nanocomposites will be systematically studied, and the influence disciplinarian of REOs and oxygen vacancy on the capacitive behaviors of 2D TMDs/REOs nanocomposites and their synergistic interaction mechanism will be also explored. These works will play an important reference value to improve the capacitive performance of the 2D r-TMOs nanomaterials.

二维氧空位过渡金属氧化物（2D r-TMOs）以独特的结构和物理化学性质作为高性能电容材料在储能方面有潜在优势。目前研究的2D r-TMOs的厚度、层间距和导电率不足，电容性能不高。超薄2D r-TMOs与特殊电子结构的稀土氧化物（REOs）复合有望得以改善，该研究国内外处于空白。本项目拟采用水热-液相剥离法或软硬模板法制备超薄2D TMOs，并将其还原为2D r-TMOs；利用不同方法将REOs复合到2D r-TMOs结构中，通过调节REOs比例、结构和氧空位量来调控2D r-TMOs的电子结构、层间距及空间构型，赋予其高电容性能，并构筑高性能超级电容器。系统研究该2D复合材料的表界面微观结构、层间距、氧空位量、组分、导电率与性能的关系，探索REOs与2D r-TMOs的协同作用机理及其对复合材料电容特性的影响规律。本项目研究结果对探索2D r-TMOs的电容性能的提高具有重要参考价值。

高性能超级电容器作为绿色环保二次能源装置可以有效缓解能源短缺和温室效应严重等问题，是符合国家新能源发展战略重大需求。二维氧空位过渡金属氧化物（2D r-TMOs）以独特的结构和物理化学性质作为高性能电容材料在储能方面有潜在优势。针对当前2D r-TMOs的电容性能不高问题，本项目通过一步水热法、化学共沉积法等方法制备了超薄氧空位2D Ce-MoO3纳米片、超薄氧空位2D Eu-MnO2纳米片、系列氧空位稀土/Co3O4（稀土=La, Yb, Y, Ce, Er, Ho, Nd, Eu）纳米复合材料、氧空位WO3/CeO2纳米复合材料、氧空位CeO2纳米材料以及C@CeO2纳米复合材料等。通过优化实验条件，实现了纳米复合材料微结构的精准调控，使得2D r-TMOs/稀土纳米复合材料具有高导电性、高比电容和高循环稳定性。同时，详细研究了纳米复合材料的表界面微观结构、晶格间距、组分、导电率以及氧空位缺陷度等对其电容性能的影响，深入探索了稀土与2D r-TMOs之间的协同作用机制，为2D r-TMOs/稀土纳米复合材料在超级电容器中的潜在应用提供了理论依据。最后构建了基于2D r-TMOs/稀土纳米复合材料超级电容器，所制备的器件具有高比电容、高循环稳定性、高能量密度和高功率密度，在未来有望得到应用。. 通过本基金资助，在Advanced Energy Materials、Small、ACS Applied Materials & Interfaces、ChemSusChem等期刊上发表SCI论文29篇，其中影响因子大于5.0 的SCI 论文18篇；申请8项国家发明专利，其中4项已授权，培养硕士毕业生11名，参加国内学术会议13人次。