Photocatalytic water splitting is one of the methods to produce hydrogen fuel by reducing the water into the oxygen and hydrogen provided that the bandgap of one catalyst is larger than +1.23 eV. In this paper, based on density functional theory, we investigated the structural, electronic and optical properties of heterostructure MoS₂ (WS₂) paired with GaN and we found out that MoS₂/GaN/MoS₂, WS₂/GaN and WS₂/GaN/WS₂ vdW heterostructures are potential photocatalysts for photocatalytic applications. From the band structure and electronic partial density of states (PDOS), we confirm that all simulated heterostructures are direct semiconductors of type II band alignment with valence band maximum and conduction band minimum localized at pz orbital N atom of GaN and dz² orbital Mo (or W) atom of MoS₂ and WS₂ respectively. The band offset induced by efficient interlayer charge transfer form a staggered gap which aids in exciton disassociation and charge separation. Our studied models are expected to harvest UV to visible light with absorption coefficient up to 3.38 × 10^-5 cm^-1 at wavelength of 102 nm. On top of that, our proposed heterosystem are also believed to be a promising device for various optoelectronic application specifically in from UV to near-infrared with high performance.

如果一种催化剂的带隙大于+1.23 eV，则光催化水分解是通过将水还原为氧气和氢气来生产氢燃料的方法之一。本文基于密度泛函理论，研究了与GaN配对的异质结构MoS ₂（WS ₂）的结构，电学和光学性质，发现MoS ₂ / GaN / MoS ₂，WS ₂ / GaN和WS ₂ /氮化镓/ WS ₂vdW异质结构是用于光催化应用的潜在光催化剂。从能带结构和电子部分态密度（PDOS），我们确认所有模拟的异质结构都是II型能带对准的直接半导体，其价带最大和导带最小位于GaN的pz轨道N原子和dz ²轨道Mo（或W）分别为MoS ₂和WS _2的原子。由有效的层间电荷转移引起的带偏移形成交错的间隙，这有助于激子解离和电荷分离。我们研究的模型有望将紫外线吸收到可见光，吸收系数高达3.38×10 ^-5  cm ^-1在102 nm的波长下 最重要的是，我们提出的异质系统也被认为是一种有前景的器件，可用于各种光电应用，特别是从UV到高性能的高性能。