Adjovi Sena E, Calatayud Monica, Gracia Lourdes
Sorbonne Université, CNRS, MONARIS, CNRS-UMR 8233, 4 Place Jussieu, F-75005 Paris, France.
Departament de Química Física, Universitat de València, 46010 Burjassot, Spain.
Nanomaterials (Basel). 2025 Aug 29;15(17):1328. doi: 10.3390/nano15171328.
Reactive oxygen species (ROS) play a central role in photocatalytic processes relevant to environmental remediation and clean energy. This work focused on the computational investigation of ZnO surface reactivity toward HO and O adsorption, as a preliminary step in understanding ROS generation pathways. Surface stability and adsorption energies for isolated and co-adsorbed HO and O molecules on different ZnO surfaces (both in their pristine form and with oxygen vacancies) were evaluated using DFT calculations at the PBE-D3 level under various surface coverages. The introduction of vacancies on the pristine (001) and (100) surfaces enhanced O binding, particularly in inclined configurations at the defect sites, with the adsorption energies reaching -2.63 eV and -2.04 eV, respectively. However, the (110) surface showed very strong HO binding, but weak O adsorption, which only modestly improved with vacancies. Co-adsorption of HO and O exhibited synergistic stabilization, especially on the (001) and (100) surfaces, where ROS were formed through proton transfers either between adsorbed HO and O or between HO and surface oxygen atoms. These findings provide detailed insight into the mechanistic role of surface defects in ROS generation and support the rational design of ZnO-based photocatalysts.
活性氧物种（ROS）在与环境修复和清洁能源相关的光催化过程中起着核心作用。这项工作聚焦于对ZnO表面对HO和O吸附的反应性进行计算研究，作为理解ROS生成途径的初步步骤。使用DFT计算在PBE-D3水平下，在各种表面覆盖度下评估了不同ZnO表面（原始形式和有氧空位）上孤立吸附和共吸附的HO和O分子的表面稳定性和吸附能。在原始的（001）和（100）表面引入空位增强了O的结合，特别是在缺陷位点的倾斜构型中，吸附能分别达到-2.63 eV和-2.04 eV。然而，（110）表面显示出非常强的HO结合，但O吸附较弱，空位仅使其略有改善。HO和O的共吸附表现出协同稳定性，特别是在（001）和（100）表面，在这些表面上，ROS通过吸附的HO和O之间或HO与表面氧原子之间的质子转移形成。这些发现为表面缺陷在ROS生成中的作用机制提供了详细见解，并支持基于ZnO的光催化剂的合理设计。
