Abstract Constructing two-dimensional (2D) heterostructure is an effective method to obtain highly efficient photocatalysts. In this work, 2D/2D TiO2/g-C3N4 heterostructures were constructed via in-situ growth of TiO2 nanosheets on the surface of g-C3N4 nanosheets by a facile hydrothermal co-assembly technique. The increased dispersion is favorable to expose more vacancies, which is beneficial to the enhancement of visible light absorption. This unique 2D/2D heterostructure exhibits ultrathin thickness and larger interfacial contact area, which results in shorter migration distance of photo-generated carriers to the surface and faster participation in photocatalytic water splitting. As expected, the optimized TiO2/g-C3N4 nanocomposites showed a higher photocatalytic hydrogen evolution performance under visible light irradiation than that of pristine g-C3N4 and TiO2 nanosheets. The improved performance can be attributed to the ultrathin nanosheet structure, the intimate interfacial contact and the presence of surface oxygen vacancies. More appealingly, this environment-friendly 2D/2D TiO2/g-C3N4 nanohybrid would attract more attention in water splitting.

中文翻译：

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构建具有改进光催化活性的二维/二维 TiO2/g-C3N4 纳米片异质结构

摘要 构建二维（2D）异质结构是获得高效光催化剂的有效方法。在这项工作中，通过简单的水热共组装技术在 g-C3N4 纳米片表面原位生长 TiO2 纳米片，构建了 2D/2D TiO2/g-C3N4 异质结构。增加的色散有利于暴露更多的空位，有利于增强可见光吸收。这种独特的 2D/2D 异质结构具有超薄的厚度和更大的界面接触面积，这导致光生载流子到表面的迁移距离更短，参与光催化水分解的速度更快。正如预期的那样，优化后的 TiO2/g-C3N4 纳米复合材料在可见光照射下表现出比原始 g-C3N4 和 TiO2 纳米片更高的光催化析氢性能。改进的性能可归因于超薄纳米片结构、紧密的界面接触和表面氧空位的存在。更吸引人的是，这种环保的 2D/2D TiO2/g-C3N4 纳米杂化物将在水分解中引起更多关注。