Photocatalytic reduction of CO₂ is one important approach to alleviate greenhouse gas emission and energy crisis, which has gained huge attention in the past decades. However, the lack of understanding complex reaction mechanism impedes new catalysts design. It is also very difficult to understand the mechanism by using only experimental approaches. For this concern, theoretical calculations can effectively supplement the experimental deficiency and thus play an important role. Recently theoretical calculations have been performed on adsorption, migration and reduction of CO₂ molecule on the photocatalyst surface, leading to useful information that have contributed greatly to this field. This review summarizes recent advances in first-principles calculations about CO₂ photoreduction over various semiconductor photocatalysts like metal oxides, sulfides and g-C₃N₄. The methods, models, adsorption and reaction pathways have been discussed in detail. The perspective about future investigation on the photocatalytic reduction of CO₂ using first principles calculations is also presented.

光催化还原CO ₂是缓解温室气体排放和能源危机的重要途径，在过去的几十年中受到了广泛关注。然而，缺乏对复杂反应机理的理解阻碍了新催化剂的设计。仅使用实验方法也很难理解该机制。针对这一问题，理论计算可以有效补充实验不足，从而发挥重要作用。最近，已经对CO ₂分子在光催化剂表面的吸附、迁移和还原进行了理论计算，得出了对该领域做出巨大贡献的有用信息。_{本综述总结了关于 CO 2}的第一性原理计算的最新进展各种半导体光催化剂（如金属氧化物、硫化物和 gC ₃ N ₄ ）的光还原。详细讨论了方法、模型、吸附和反应途径。还提出了关于使用第一性原理计算光催化还原 CO ₂的未来研究前景。