Photoelectrochemical water decomposition directly attracts water and light into hydrogen and oxygen. Among them, Si with narrow band gap and strong carrier transport ability is regarded as one of the ideal high-efficiency photocathode materials. However, Si-based photocathode is It is easy to corrode and passivate with electrolyte solution (especially strong alkali electrolyte) under illumination, which limits its application in photoelectrochemistry. It is suitable for efficient and stable operation in Si-based photocathode in strong alkaline electrolyte. The protective layer removes or weakens the coupling of the efficiency and stability of the Si-based photocathode.
In view of this, the team of Professor Wang Shuangyin of the School of Chemical Engineering of our school proposed a simple route to use crystalline oxygen-deficient TiO. 2The protective layer enhances the efficiency and stability of the photoelectric performance of the Si-based photocathode under strong alkali electrolyte. Related work was published in Nature Communications.
Compared to intact stoichiometric crystalline TiO 2Layer, gradient oxygen-deficient crystalline TiO 2The layer not only supports the stable operation of the Si-based photocathode in the strong alkaline electrolyte solution, but also provides an effective transport channel for photoexcited electrons. In addition, crystalline TiO 2The oxygen defect concentration in the layer will significantly affect the PEC hydrogen production efficiency of the entire Si-based photocathode. This work shows that the protective layer combined with the high-density crystalline structure and the gradient defect component can decouple the efficiency and stability of the Si-based photocathode. Photoelectrochemical systems that convert solar energy into fuel in a strong alkaline electrolyte provide improved direction.
In addition, the research group has made important progress in the chemical regulation of defects in photoanodes. The related work has also been published recently in Advanced Materials (Impact Factor 21.95), a leading journal in the field of materials.
