Recently, experimental and theoretical works have reported evidence indicating that photochemical processes may significantly be accelerated at heterogeneous interfaces, although a complete understanding of the phenomenon is still lacking. We have carried out a theoretical study of interface and surface effects on the photochemistry of hydrogen peroxide (H₂O₂) using high-level ab initio methods and a variety of models. Hydrogen peroxide is an important oxidant that decomposes in the presence of light, forming two OH radicals. This elementary photochemical process has broad interest and is used in many practical applications. Our calculations show that it can drastically be affected by heterogeneous interfaces. Thus, compared to gas phase, the photochemistry of H₂O₂ appears to be slowed on the surface of apolar or low-polar surfaces and, in contrast, hugely accelerated on ionic surfaces or the surface of aqueous electrolytes. We give particular attention to the case of the neat air–water interface. The calculated photolysis rate is similar to the gas phase, which stems from the compensation of two opposite effects, the blue shift of the n→σ* absorption band and the increase of the absorption intensity. Nevertheless, due to the high affinity of H₂O₂ for the air–water interface, the predicted OH production rate is up to five to six orders of magnitude larger. Overall, our results show that the photochemistry of H₂O₂ in heterogeneous environments is greatly modulated by the nature of the surface, and this finding opens interesting new perspectives for technological and biomedical applications, and possibly in various atmospheres.

最近，实验和理论工作报告的证据表明，异质界面上的光化学过程可能会显着加速，尽管仍然缺乏对这种现象的完整理解。我们使用高级从头计算方法和各种模型，对过氧化氢 (H ₂ O ₂ ) 光化学的界面和表面效应进行了理论研究。过氧化氢是一种重要的氧化剂，在光存在下分解，形成两个 OH 自由基。这种基本的光化学过程引起了广泛的兴趣，并在许多实际应用中得到应用。我们的计算表明，它会受到异构接口的极大影响。因此，与气相相比，H ₂ O ₂的光化学在非极性或低极性表面上似乎减慢，相反，在离子表面或水性电解质表面上大大加速。我们特别关注整齐的空气-水界面的情况。计算的光解速率与气相类似，源于两种相反效应的​​补偿，即n→σ*吸收带的蓝移和吸收强度的增加。然而，由于H ₂ O ₂对空气-水界面的高亲和力，预测的OH 生成率最多高出五到六个数量级。总体而言，我们的结果表明，异质环境中 H ₂ O ₂的光化学很大程度上受到表面性质的调节，这一发现为技术和生物医学应用以及可能在各种大气中的应用开辟了有趣的新视角。