The unexpected visible-light absorption, low recombination of electron–hole pairs, and high carrier mobility are found in a novel two-dimensional (2D) InSe/Zr₂CO₂ van der Waals heterostructure for overall water splitting photocatalysis. The photocatalytic mechanism has been systematically investigated using first-principles calculations for the first time. We prove that the 2D InSe/Zr₂CO₂ heterostructure is a robust and promising visible-light photocatalyst with several distinct advantages, as follows. It has a direct band gap of 1.81 eV, which is a more favorable band gap for visible-light photocatalysis. Its type-II band alignment directly leads to a significant electron–hole separation with electrons (holes) localized in the InSe (Zr₂CO₂) monolayer. The indirect band gap of the InSe (Zr₂CO₂) monolayer further suppresses the electron–hole recombination in it. Naturally, the recombination of the photogenerated electrons and holes is greatly suppressed in the InSe/Zr₂CO₂ heterostructure, which improves the solar energy utilization effectively. Moreover, a large optical absorption coefficient (10⁵ cm^–1) has been confirmed in the 2D InSe/Zr₂CO₂ heterostructure with the electron (hole) mobility reaching up to 10⁴ (10³) cm² V^–1 s^–1, which is highly beneficial and desirable for enhancing its photocatalytic efficiency.

中文翻译：

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用于整体水分解的新型InSe / Zr ₂ CO ₂异质结构中可见光光催化效率的提高

在新型二维（2D）InSe / Zr ₂ CO ₂范德华异质结构中，发现了出乎意料的可见光吸收，电子-空穴对的低重组以及高载流子迁移率，可用于整体水分解光催化。首次使用第一性原理系统地研究了光催化机理。我们证明了2D InSe / Zr ₂ CO ₂异质结构是一种强大而有前途的可见光光催化剂，具有以下几个明显的优点。它的直接带隙为1.81 eV，这对于可见光光催化而言是更有利的带隙。它的II型能带对准直接导致InSe（Zr ₂ CO ₂）单层中存在的电子（空穴）发生明显的电子-空穴分离。InSe（Zr ₂ CO ₂）单层的间接带隙进一步抑制了其中的电子-空穴复合。自然地，在InSe / Zr ₂ CO _2中极大地抑制了光生电子和空穴的复合。异质结构，有效提高了太阳能的利用率。此外，已证实在2D InSe / Zr ₂ CO ₂异质结构中具有大的光吸收系数（10 ⁵ cm ^–1），其电子（空穴）迁移率达到10 ⁴（10 ³）cm ² V ^–1 s ^{– 1}，这对于提高其光催化效率是高度有益和理想的。