Abstract Two-dimensional (2D) MXenes have garnered tremendous interest due to their novel properties. In the present study, the exfoliation energy, structural, electronic and optical properties of (Zr0.5Hf0.5)2CO2 have been investigated by density functional theory calculations. We found that the dynamically and thermally stable (Zr0.5Hf0.5)2CO2 have ideal band gap, high redox potential, as well as unexpectedly high carrier mobility and efficient separation of photogenerated electron–hole pairs. It is highlighted that (Zr0.5Hf0.5)2CO2 shows better visible light harvest than pristine Zr2CO2 and Hf2CO2. Additionally, the simulations of the adsorption and decomposition of water molecules on the 2D (Zr0.5Hf0.5)2CO2 surface have been studied to unravel the mechanism of the hydrogen production process. These insights provide eloquent evidence that (Zr0.5Hf0.5)2CO2 monolayer is potentially an efficient visible-light driven water-splitting photocatalyst.

中文翻译：

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二维 (Zr0.5Hf0.5)2CO2：一种具有高效载流子分离能力的有前途的可见光水分解光催化剂

摘要 二维 (2D) MXenes 由于其新颖的特性而引起了极大的兴趣。在本研究中，通过密度泛函理论计算研究了 (Zr0.5Hf0.5)2CO2 的剥离能、结构、电子和光学性质。我们发现动态和热稳定的 (Zr0.5Hf0.5)2CO2 具有理想的带隙、高氧化还原电位，以及出乎意料的高载流子迁移率和光生电子 - 空穴对的有效分离。值得强调的是，(Zr0.5Hf0.5)2CO2 显示出比原始 Zr2CO2 和 Hf2CO2 更好的可见光捕获。此外，还研究了水分子在 2D (Zr0.5Hf0.5)2CO2 表面吸附和分解的模拟，以揭示制氢过程的机制。这些见解提供了雄辩的证据（Zr0.