The development of heterojunction photocatalysts for hydrogen peroxide (H₂O₂) generation is both environmentally sustainable and cost-effective but presents considerable challenges. In this study, we synthesized hollow tubular indium oxide (In₂O₃) by calcining In-MIL-68 and subsequently composited it with polydopamine (PDA) via in-situ self-polymerization. This process resulted in the formation of an In₂O₃/PDA step-scheme (S-scheme) heterojunction. The optimized sample demonstrated H₂O₂ production rates approximately 2.1 and 4.5 times higher than the pure In₂O₃ and PDA, respectively. The enhanced photocatalytic performance of the In₂O₃/PDA composite is the result of several synergistic factors: increased light absorption due to the hollow structure, a larger specific surface area, and high separation efficiency of photo-generated electron-hole pairs facilitated by the S-scheme heterojunction. In-situ irradiated X-ray photoelectron spectroscopy (ISI-XPS) confirmed the charge transfer pathway follows the S-scheme mechanism. This work not only highlights a practical method for constructing inorganic/organic S-scheme heterojunction photocatalysts but also provides a detailed analysis of their underlying mechanisms, paving the way for more efficient and sustainable photocatalytic systems.

中文翻译：

---

便捷合成空心管式 In2O3/PDA S 型无机/有机异质结光催化剂及其机理


用于生成过氧化氢 （H₂O₂） 的异质结光催化剂的开发既具有环境可持续性又具有成本效益，但也存在相当大的挑战。在这项研究中，我们通过煅烧 In-MIL-68 合成了空心管状氧化铟 （In₂O₃），随后通过原位自聚合将其与聚多巴胺 （PDA） 复合。这个过程导致形成 In₂O₃/PDA 阶跃型 （S-scheme） 异质结。优化后的样品表明，H₂O₂ 的生成速率分别比纯 In₂O₃ 和 PDA 高约 2.1 倍和 4.5 倍。In₂O₃/PDA 复合材料的光催化性能增强是几个协同因素的结果：由于中空结构而增加的光吸收、更大的比表面积以及 S 型异质结促进的光生电子-空穴对的高分离效率。原位辐照 X 射线光电子能谱 （ISI-XPS） 证实电荷转移途径遵循 S 方案机制。这项工作不仅突出了构建无机/有机 S 型异质结光催化剂的实用方法，还详细分析了其潜在机制，为更高效和可持续的光催化系统铺平了道路。