Stripe Arrays Comprising Uniform Concave Nanocrystals for Electrocatalytic Nitrate Reduction to Ammonia

Stripe patterns provide profound insights into physicochemical properties governed by the structural characteristics of their constituent building blocks. However, simultaneously controlling the geometric shape, crystallographic features, and spatial arrangement of these building blocks remains challenging. Herein, we report the successful synthesis of stripe-patterned concave single crystals (SP-CSC) via a facile drying-mediated process. The SP-CSC structure consists of concave nanocrystal building blocks that are uniformly oriented and arranged into stripe-patterned arrays on nanosheets, integrating concave geometry, uniform orientational alignment, and stripe-patterned arrangement. The drying temperature is critical for coordinating supersaturation-driven nucleation, oriented growth, and contact-line stick-slip motion on nanosheets, ultimately leading to the formation of SP-CSC. This strategy demonstrates the potential to enhance electrocatalytic ammonia synthesis performance by regulating the structural features of building blocks in stripe-based systems. It also provides inspiration for designing precise patterns that integrate multiple structural features to explore coupled functionalities.