Solar radiation is a sustainable, unlimited source of energy for electricity and chemical reactions, yet the conversion efficiency of actual processes is limited and controlled by photocarriers migration and separation. Enhancing the conversion efficiency would require to suppress the recombination of photogenerated electron–hole pairs and improve the low redox potentials. This can be done during the growth of step-scheme (S-scheme) heterojunctions. Here we review the charge transfer of S-scheme heterojunctions involving a reduction and oxidation photocatalyst in staggered band arrangement with Fermi level differences. We present factors determining the validation of the S-scheme mechanism with respective characterization techniques, including in situ and ex situ experiments, and theoretical studies. We show mechanistic drawbacks of traditional photocatalytic systems to highlight the advantages of S-scheme photocatalysts. We describe co-catalyst loading, bandgap tuning, and interfacial optimization that ultimately achieve highly efficient photocatalysis. Last, application for water splitting, CO₂ conversion, pollutant degradation, bacterial inactivation and others is discussed.

太阳辐射是用于电力和化学反应的可持续的，无限的能源，但是实际过程的转换效率受到光载流子迁移和分离的限制和控制。提高转换效率将需要抑制光生电子-空穴对的复合并改善低氧化还原电势。这可以在逐步方案（S方案）异质结的生长过程中完成。在这里，我们综述了费米能级交错带安排中涉及还原和氧化光催化剂的S型异质结的电荷转移。我们介绍了使用相应的表征技术（包括原位和异位实验以及理论研究）确定S方案机理验证的因素。我们展示了传统光催化系统的机械缺陷，以突出S方案光催化剂的优势。我们描述了最终实现高效光催化的助催化剂负载，带隙调节和界面优化。最后，CO的水分解应用_讨论了2转化，污染物降解，细菌灭活等。