CO2是最常见的化合物，作为潜在的碳一资源，可用于制备多种高附加值的化学品，如一氧化碳、甲烷、甲醇、甲酸等。传统的热催化转化CO2方法能耗高，反应条件苛刻。因此，如何在温和条件下高效地将CO2转化成高附加值的化学品，一直以来是催化领域的研究热点和难点之一。光催化技术反应条件温和、绿色环保。然而，纯光催化反应普遍存在太阳能利用效率有限，光生载流子分离效率低等问题。针对上述问题，在光催化的基础上引入电催化，可以提高载流子的分离效率，在较低的过电位下，实现多电子、质子向CO2转移，从而提高催化反应效率。总之，光电催化技术可以结合光催化和电催化的优势，提高CO2催化还原反应效率，为清洁、绿色利用CO2提供了一种新方法。本文依据光电催化CO2还原反应基本过程，从光吸收、载流子分离和界面反应等三个角度综述了光电催化反应的基本强化策略，并对未来可能的研究方向进行了展望。
Carbon dioxide is the most common compound. As a potential source of carbon, it can be used to prepare a variety of high value-added chemicals, such as carbon monoxide, methane, methanol, and formic acid. The traditional method of thermal catalytic conversion of CO2 requires high energy consumption and harsh reaction conditions. Therefore, the efficient conversion of CO2 to value-added chemicals under mild conditions has long been an area of great interest in the field of catalysis. Photocatalysis usually takes place under mild reaction conditions and is environmentally friendly. However, pure photocatalytic reactions generally have a limited solar energy utilization efficiency and low separation efficiency of photogenerated charge carriers. In view of the above problems, the introduction of electrocatalysis on the basis of photocatalysis can improve the charge separation efficiency. At a lower overpotential, multi-electrons and protons can be transferred to CO2, thus improving the catalytic reaction efficiency. Photoelectrochemical catalysis combines the advantages of photocatalysis and electrocatalysis to improve the efficiency of the catalytic reduction of CO2, offering a new method for the clean utilization of CO2. According to the principle of photocatalysis, the absorption capacity of a semiconductor is governed by its band structure. Optimization of the band structure is a major strategy to enhance the absorptivity of photocatalysts. In addition, the loading of light-absorbent materials on photocatalysts is an effective way to enhance the photocatalytic absorption of a photocatalytic system. During photoelectrocatalytic CO2 reduction, numerous photogenerated charge carriers recombine in bulk and on the surface of the catalyst, greatly reducing the efficiency of the catalytic reaction. Therefore, increasing the separation efficiency of charge carriers is an important means to improve the photoelectrocatalytic efficiency. In photoelectrocatalytic CO2 reduction, heterojunction construction and electric field formation often lead to the efficient separation of charge carriers. The interfacial reaction is a crucial step in the photoelectrocatalytic process. After