Strain modulation of phase transformation of noble metal nanomaterials

Abstract Noble metals have been extensively studied owing to their high chemical stability and outstanding catalytic properties in various important reactions. However, their large‐scale application of noble metals is still challenged by their high expense and scarcity on the earth, as well as the yet insufficient activity to give a satisfying performance. For decades, enormous research efforts have been devoted to the nanoengineering of noble metal nanocrystals, such as the size‐, composition‐, shape‐, and/or morphology‐controlled syntheses, and impressive advances have been achieved. Meanwhile, the discovery that the crystal structure of noble metal nanocrystals also has a significant impact on their properties opened a new pathway that modulates the crystal phases of noble metals to achieve better properties. Among the feasible methods for crystal phase transformation, the presence of strain is not negligible. Strain generally has two roles: the driving force of the phase transformation and/or the origin of the distinct properties of the new crystal structure. Strain effect on noble metals has also been extensively studied due to its capability of fine‐tuning the surface catalytic activity. Therefore, combining the two hot research trends together, a possible research pathway is emerging. That is, utilizing the potential synergistic effect between novel crystal phases and the subsequent lattice strain to boost the performance of noble metal nanocrystal even further. Herein, a brief summary of the currently discovered noble metal phases and strain effect and the introduction of strain related phase modulation techniques along with the catalytic applications will be presented. Finally, a brief conclusion and future perspective is given.