Two-dimensional van der Waals heterostructure CdO/PtSe2: promising visible light photocatalyst for overall water splitting
Two-dimensional van der Waals heterostructure CdO/PtSe2: promising visible light photocatalyst for overall water splitting
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二维范德华异质结构 CdO/PtSe2：用于整体水分解的有前途的可见光光催化剂
DOI：
10.1039/d0cp03564e
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发表时间：
2020
影响因子：
3.3
通讯作者：
Ji Weixiao
中科院分区：
文献类型：
--
作者：
Zhang Wei;Ji Weixiao
由于化石燃料的日益枯竭和严重的环境污染，光催化分解水制氢被认为是清洁能源的替代策略。本文采用杂化密度泛函方法，系统地研究了不同堆积方式的CdO/PtSe 2的货车德瓦耳斯异质结构的结构、电子和光学性质.异质结构被发现是动态稳定的，并具有II型带排列与一个大的内置电场，这是有利于有效的空间分离的光生载流子。通过揭示固有的界面偶极子依赖的光催化机制，我们发现所有图案的带边跨越水的氧化还原水平，尽管AB-1图案具有小于1.23 eV的带隙。此外，与单层相比，异质结构显示出具有大吸收系数（105 cm-1）的全局改善的光学吸收，证明了增强的光催化活性。与石墨烯/C3 N4和MoS 2/C3 N4等双层体系相比，CdO/PtSe 2具有更好的可见光吸收等优点，是一种很有前途的光催化水分解体系。
Due to the gradual depletion of fossil fuels and the serious environmental pollution, hydrogen generation by photocatalytic water splitting has been considered as an alternative strategy for clean energy. Herein, using hybrid density functional calculations, we systematically study the structural, electronic and optical properties of van der Waals heterostructure CdO/PtSe2 with different stacking patterns. The heterostructure is found to be dynamically stable, and has type-II band alignment with a large built-in electric field, which is favorable for the efficient spatial separation of photogenerated charge carriers. By revealing the intrinsic interface dipoles dependent photocatalytic mechanisms, we find the band edges of all patterns straddle the water redox levels despite the AB-1 pattern having a bandgap less than 1.23 eV. Moreover, the heterostructure shows globally improved optical absorptions with a large absorption coefficient (105 cm−1) compared to the single layers, demonstrating the enhanced photocatalytic activity. Comparing with widely discussed bilayer systems like graphene/C3N4 and MoS2/C3N4, the CdO/PtSe2 simultaneously has several advantages or peculiarities such as the more favorable absorption of visible light, therefore CdO/PtSe2 is a promising candidate and a unique system for photocatalytic water splitting.