Current work reports the study of Ag nanocrystals (NCs) decorated doubly anodized (DA) TiO₂ nanotubes (NTs) thin film as an efficient photoelectrode material for water splitting and photocatalytic hydrogen gas production. DA process has been shown to be capable of producing less defective NTs and creating additional spacious gaps in between NT bundles to allow efficient and uniform integration of Ag NCs. By employing photoreduction method, Ag NCs can be deposited directly onto NTs, where the size and density of coverage can be maneuvered by merely varying the concentration of Ag precursors. Field emission scanning electron microscope (FESEM) images show that the Ag NCs with controllable size are homogeneously decorated onto the walls of NTs with random yet uniform distribution. X-ray diffraction (XRD) results confirm the formation of anatase TiO₂ NTs and Ag NCs, which can be well indexed to standard patterns. The decoration of metallic Ag NCs onto the surface of NTs demonstrates a significant enhancement in the photoconversion efficiency as compared to that of pristine TiO₂ NTs. Additionally, the as-prepared nanocomposite film also shows improved efficiency when used as a photocatalyst platform in the production of hydrogen gas. Such improvement in the performance of water splitting and photocatalytic hydrogen gas production activity can be credited to the surface plasmonic resonance of Ag NCs present on the surface of the NTs, which renders improved light absorption and better charge separation. The current work can serve as a model of study for designing more advanced nanoarchitecture photoelectrode for renewable energy application.

中文翻译：

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Ag纳米晶体在TiO2纳米管平台上的光沉积以增强水分解和氢气的产生

当前的工作报道了装饰双阳极氧化（DA）TiO ₂的Ag纳米晶体（NC）的研究碳纳米管（NTs）薄膜作为水分解和光催化氢气生产的有效光电极材料。事实证明，DA工艺能够生产出较少缺陷的NT，并在NT束之间产生额外的宽敞间隙，以实现Ag NC的高效，统一集成。通过采用光还原法，可以将Ag NCs直接沉积在NTs上，在其中仅通过改变Ag前体的浓度就可以控制覆盖的大小和密度。场发射扫描电子显微镜（FESEM）图像显示，具有可控尺寸的Ag NCs均匀地装饰在NTs的壁上，具有随机而均匀的分布。X射线衍射（XRD）结果证实了锐钛矿型TiO ₂的形成NT和Ag NC，可以很好地索引到标准模式。与原始TiO ₂ NT相比，将金属Ag NCs装饰在NTs表面上显示出光转换效率的显着提高。另外，当用作氢气生产中的光催化剂平台时，所制备的纳米复合膜还显示出改进的效率。这种水分解性能和光催化氢气生产活性的改善可以归因于存在于NTs表面上的Ag NCs的表面等离子体共振，这改善了光吸收和更好的电荷分离。当前的工作可以作为设计可再生能源应用的更高级的纳米结构光电极的研究模型。