Trap-array slippery surfaces for high-throughput, precise, and flexible evaporation-induced supraparticle synthesis

Supraparticles, the small aggregation entities of functional micro/nanoparticles, are crucial in materials science, chemistry, and nanotechnology owing to their unique properties and wide range of applications. Evaporation-driven self-assembly of colloidal droplets on surfaces has proven effective for supraparticle synthesis. However, challenges such as low production rates, adhesion risks, cross-contamination, and limited flexibility continue to hinder the widespread adoption of this method. To address these challenges, this study proposes an innovative strategy that uses the novel lotus-seed head and Nepenthes-inspired trap-array slippery surfaces (TASS). These surfaces feature a macroscopic trap array and a lubricant layer for high-throughput supraparticle synthesis. The lubricant traps provide a self-locating and stable lubrication effect, enabling the retreatment of addressable droplet array contact lines during evaporation, leading to the successful fabrication and collection of the supraparticle array. Additionally, the method demonstrates high synthesis flexibility, allowing for the creation of various supraparticle structures, morphologies, and porosities. As a proof of concept, core-shell magnet-actuated photocatalytic supraparticles were synthesized using TASS and showed enhanced contaminant degradation efficiency. This novel surface-template strategy provides a promising approach for large-scale, evaporation-driven supraparticle synthesis, with potential applications in catalysis, energy storage, and carbon capture.