光催化氧化法制备孔洞形貌可控的多孔还原氧化石墨烯及机理研究

Holey graphene overcomes the impermeability of pristine graphene sheets towards gas molecules and electrolytes, which is beneficial for its applications in photocatalysis and energy conversion and storage. Meanwhile, the creation of morphology-controllable nanoholes in graphene sheets is able to open and tune the band gap of graphene materials, making it more suitable for FET devices, and extends its applications in biology, functional membranes, and nanostructure fabrications. In this project, we propose to in-situ grow TiO2 nanostructures with different morphologies on graphene oxide nanosheets independently, and study their growth mechanisms. The support material, graphene oxide, is then reduced. After that, we plan to create nanoholes in the reduced graphene oxide nanosheets via the photocatalytic oxidation ability of TiO2 nanostructures. The template effect of TiO2 nanostructures on the morphology of nanoholes (right after the TiO2 nanostructures come off) in reduced graphene oxide sheets will be investigated. The nanohole evolution process and the chemical changes taken place in the graphene material during the photocatalytic oxidation will be unveiled. In order to gain more deep insights in the nanohole formation process, the products from the photocatalytic oxidation of reduced graphene oxide will be collected and determined both qualitatively and quantitatively. Furthermore, the influence of the decomposed products on the environment will be assessed subsequently. Over all, this project would afford a photocatalytic oxidation way to obtain holey graphene with specific nanohole morphology, and disclose the photo-chemical stability of graphene-based nanomaterials and their influence to the environment.

多孔石墨烯能克服石墨烯纳米片对气体分子和电解质不通透的缺点，提高其在光催化、能源转换与储存等领域中的应用性能。同时，制备纳米孔洞形貌可调控的多孔石墨烯能精确调控石墨烯材料的禁带宽度，对拓展石墨烯在FET、生物、膜分离、纳米材料组装等领域中的应用具有重要的研究意义。本项目拟在氧化石墨烯纳米片上原位生长不同形貌的TiO2纳米材料，并研究它们的生长机理。还原基底氧化石墨烯后，提出利用TiO2纳米材料的光催化氧化作用氧化分解还原氧化石墨烯而制备多孔还原氧化石墨烯，并研究TiO2纳米材料对纳米孔洞形貌的模板作用。考察纳米孔洞的衍变行为，包括纳米孔洞形状的变化过程和还原氧化石墨烯的化学结构变化。跟踪研究还原氧化石墨烯在光催化氧化分解后的产物组成及含量变化，并评估分解产物对环境的影响。本项目能为制备具有规则纳米孔洞形貌的多孔石墨烯提供方法参考，为评价石墨烯类材料的光化学稳定性和对环境的影响提供理论依据。

多孔石墨烯能克服石墨烯纳米片对气体分子和电解质不通透的缺点，提高其在光催化、能源转换与储存等领域中的应用性能。同时，制备纳米孔洞形貌可调控的多孔石墨烯能精确调控石墨烯材料的禁带宽度，对拓展石墨烯在FET、生物、膜分离、纳米材料组装等领域中的应用具有重要的研究意义。本项目成功合成了TiO2微球/GO复合材料，并揭示了TiO2微球的生长机理，详细阐述了TiO2微球/GO复合材料的光化学稳定性。研究结果表明TiO2/GO复合材料在长时间紫外光照条件下，GO存在进一步氧化甚至分解的现象。这一研究成果，为评价石墨烯类材料的光化学稳定性和对环境的影响提供理论依据。除此之外，我们还探索性地开辟了新的研究方向包括g-C3N4薄膜电极的制备及其在光电化学电池水分解和环境治理方面的应用、TiO2纳米管的限域光催化效应、及光电化学发光在传感探测中的应用，并取得了较好的研究成果。