Читать книгу Heterogeneous Catalysts - Группа авторов - Страница 62

This method is mainly used for the deposition of metals on semiconductor materials (see for examples Chapters 11, 31, and 37 on the principles of photocatalysis). Carbon nitride is a carbon‐based semiconductor material. Pd nanoparticles have been deposited on carbon nitride, by photoassisted reduction of Pd(NO₃)₂ using ultraviolet (UV) illumination [51]. This method led to uniform distribution of Pd nanoparticles with the size of 6 ± 0.7 nm, and exhibited higher stability in ORR than the commercial Pt on carbon catalyst. A variant of photodeposition is the photo‐Fenton process, which capitalizes on the homogeneous photoreaction between dissolved Fe²⁺ and H₂O₂. On CNTs, Co and Fe nanoparticles (2–5 nm) have been deposited under UV illumination through a photo‐Fenton process [52]. In this process, UV‐induced hydroxyl radicals (^•OH) oxidize the CNT surface in the presence of Fe or Co ions that are reduced and subsequently precipitated on the CNT surface in the form of nanoparticles.