【摘要】 基于单层C₂N和ZnO,构建了一种新型2D范德华（vdW）异质结。在第一性原理下进行密度泛函理论计算，系统地研究了C₂N/ZnO异质结的光催化应用。结果表明，C₂N/ZnO异质结具有1.68 eV的直接带隙，其Ⅱ型带对准可以促使光生电子和空穴分离在不同层上。由Mulliken电荷布局分析可知，C₂N层有0.53个电子转移到ZnO层，在异质结界面处形成了一个较强的内建电场E_int,抑制了光生电子空穴对的复合。此外，C₂N/ZnO异质结的带边位置跨过了pH=2～7时的水氧化还原电位，同时拉伸应变可以增大其光催化水分解pH范围。特别地，C₂N/ZnO异质结保留了高载流子迁移率和优异的光吸收性能，太阳能-氢能（STH）转换效率可达到24.6%。因此，C₂N/ZnO异质结是一种具有应用前景的水分解光催化剂。更多还原

【Abstract】 The novel 2D van der Waals（vdW） heterojunction is constructed based on C₂N and ZnO monolayers. In this work, we investigate the photocatalytic application of C₂N/ZnO heterojunction systematically by conducting density functional theory calculations with first-principles. The results clear that the C₂N/ZnO heterojunction is a direct band gap semiconductor with 1.68 eV band gap, and its type-II band alignment can facilitate the separation of photoexcited electrons and holes on different layers. From the Mulliken population analysis, 0.53 electrons from the C₂N layer are transferred to the ZnO layer, forming a formidable built-in electric field E_int that curbs the recombination of photoexcited electron-hole pairs at the interface. Additionally, the band edge positions of the C₂N/ZnO heterojunction straddle the water redox potential at pH=2 to 7, and the pH range of photocatalytic water decomposition increases under the tensile strain. Especially, the high carrier mobility and outstanding light absorption characteristic are retained in the C₂N/ZnO heterojunction, and the solar-to-hydrogen（STH） conversion efficiency is as high as 24.6%. So the C₂N/ZnO heterojunction is a prospective water splitting photocatalyst.更多还原