Structural Tuning of Nanostructures: Influence of Polymorphism and Stoichiometry on Photo‐ and Electrocatalytic Performance

The utilization of crystal structures has been recognized as a powerful strategy for enhancing photo‐ and electrocatalytic performance that often stems from the existence of different polymorphic forms or variations in elemental stoichiometry. Both factors govern the electronic and surface properties, which in turn influence the material's catalytic behavior. The first part of the discussion explores polymorphism in nanostructures. The existence of multiple polymorphic forms can lead to substantial variations in catalytic reactivity, making it essential to understand their effects on efficiency in order to enable the rational selection and targeted design of materials for specific catalytic reactions. The review shifts the focus to stoichiometry, leading to the formation of distinct crystal structures and showing how these structural variations correlate with catalytic activity. By altering the ratio of elements within a compound, it is possible to stabilize different crystal phases, each exhibiting unique surface properties and active sites that impact their performance in catalytic reactions. To support these discussions, several case studies are presented highlighting these aspects. Through this comprehensive overview, the review aims to provide perspectives into the structure–activity relationship and demonstrate the potential of crystal structure as a guiding principle for the future design of efficient catalytic materials.