Xing Jinqi, Shen Junxia, Wei Zhihe, Zheng Zhangyi, Cao Ying, Chen Cong, Olu Pierre-Yves, Dong Wen, Peng Yang, Shen Mingrong, Fan Ronglei
School of Physical Science and Technology, Jiangsu Key Laboratory of Thin Films, Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou, 215006, China.
Soochow Institute of Energy and Material Innovations, College of Energy, Soochow University, Suzhou, 215006, China.
Small. 2025 Apr;21(15):e2502226. doi: 10.1002/smll.202502226. Epub 2025 Mar 6.
Integrating nanostructured catalysts with semiconductors is a prevalent strategy for the design of photoelectrochemical (PEC) photocathodes toward CO reduction reaction (CORR). However, it is still a challenge to achieve high efficiency and selectivity due to the incompatible catalyst/semiconductor heterogeneous interface. Here, it is proposed that engineering oxygen vacancy in the TiO interlayer plays a multifunctional role in boosting the PEC activity and selectivity for the CORR on a Bi catalyst modified Si photocathode (denoted as Si/dT/Bi). It is discovered that oxygen vacancy in the TiO interlayer accelerates the carrier transport. These oxygen vacancies also promote the growth of the Bi-based catalysts as sponge-like nanostructures during the photoelectro-deposition process. Numerous PEC experimental results combined with in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy reveal that these sponge-like Bi nano-catalysts on Si/dT/Bi photocathode provide a high density of active sites for CO adsorption and promote the kinetics for HCOOH production by accelerating the formation of the key intermediate of *OCHO. This oxygen vacancy engineering in interlayer provides a unique route for future advancements in CO reduction technologies.
将纳米结构催化剂与半导体相结合是设计用于光催化二氧化碳还原反应（CORR）的光电化学（PEC）光阴极的一种普遍策略。然而，由于催化剂/半导体异质界面不相容，实现高效率和高选择性仍然是一个挑战。在此，有人提出在TiO中间层中设计氧空位在提高Bi催化剂修饰的Si光阴极（表示为Si/dT/Bi）上的PEC活性和CORR选择性方面具有多功能作用。研究发现，TiO中间层中的氧空位加速了载流子传输。这些氧空位还在光电沉积过程中促进了Bi基催化剂以海绵状纳米结构的形式生长。大量的PEC实验结果与原位衰减全反射表面增强红外吸收光谱相结合表明，Si/dT/Bi光阴极上的这些海绵状Bi纳米催化剂为CO吸附提供了高密度的活性位点，并通过加速关键中间体*OCHO的形成促进了HCOOH生成的动力学。中间层中的这种氧空位工程为未来CO还原技术的进步提供了一条独特的途径。
