常州大学低碳清洁能源与安全高效燃烧科研团队孙运兰教授课题组2022级硕士研究生田徐力在Surfaces and Interfaces期刊发表了题为“First-principles investigation of the two-dimensional van der Waals g-C3N4/ g-ZnO heterojunction: Enhancing the photocatalytic hydrogen evolution activity”的研究论文。

   二维材料由于其超高的稳定性、可调的性质以及高比表面积带来更多暴露的活性位点，从而帮助光生载流子更快地迁移，从而有效地延长光生成载流子的寿命，近年来受到研究人员的青睐，并被广泛应用于光催化领域。

本研究利用第一性原理计算，研究了一种新型二维vdW异质结CNZNO光催化制氢的可行性。CNZNO结构稳定，具有z型异质结，带隙为2.2884 eV，具有优异的光吸收性能。当g-C3N4单层与g-ZnO接触时，由于电位的显著下降，在CNZNO界面处产生了一个内部电场，从而阻碍了光生电子空穴的重组。与g-C₃N₄和g-ZnO相比，CNZNO具有较高的光吸收效率，达到10^5等，并且在可见光区具有显著提高的光吸收系数。在0%应变下，CNZNO的能带结构与中性条件下的水裂解氧化还原电位完全一致，并且可以通过双轴应变调节带隙范围，从而提高CNZNO的光催化性能。CNZNO中HER的吉布斯自由能变化为1.089 eV，对应于OER的过电位为1.155 V。此外，CNZNO的STH能量转换效率在不同环境下保持稳定。

  这些结果对于利用g-ZnO作为基底材料构建异质结和提高光催化性能具有重要意义。

    该论文第一作者田徐力是常州大学2022级能源动力专业硕士研究生，常州大学朱宝忠教授为通讯作者，常州大学是第一作者和通讯作者单位！该研究成果得到了国家自然科学基金项目资助！

英文摘要：

  The 2D heterostructure composed of two two-dimensional (2D) catalysts combined by van der Waals force constraints can significantly improve the photocatalytic performance, which provides a new idea for the renewable energy and the pollutant degradation. In this research, a catalyst for photocatalysis was developed by combining g-ZnO and g-C₃N₄, and their electronic and optical characteristics were analyzed by using a density-functional theory (DFT). g-C₃N₄/g-ZnO (CNZNO), a 2D layered semiconducting material with an indirect bandgap (Eg=2.2884 eV) and a typical Z-type heterojunction structure. This structure can effectively prevent the recombination of photogenerated carriers at the interface, which improves their lifetime, and the energy band edges of the catalyst are aligned appropriately to facilitate hydrogen production via water splitting. In the heterojunction of CNZNO, the charge dissipation region (hole aggregation region) occurs near the surface of g-C₃N₄, the charge accumulation region occurs near the surface of g-ZnO, and the charge transfers from g-C₃N₄ to g-ZnO. The uneven charge distribution caused by charge transfer, which generates an electric field at the heterojunction interface. The CNZNO heterojunction has very stable photocatalytic hydrogen production (STH) efficiency and can be adapted to different environments. This result contributes to the development of efficient and stable photocatalysts.

图解摘要：

原文链接：https://doi.org/10.1016/j.surfin.2024.104919 

撰稿：2022级硕士研究生田徐力    审核：朱宝忠