Microenvironment regulation in nanomaterial synthesis.

The controllable synthesis of nanomaterials serves as the core driving force for the development of energy, catalysis, biomedicine and other fields. Their performance depends on microstructures including size and morphology, whose formation is precisely regulated by the synthetic microenvironment. Traditional macroscale and extensive synthesis suffers from issues such as inhomogeneous mixing and uncontrollable mass and heat transfer, leading to non-uniform product structures that impede the precise construction of complex architectures. As an innovative preparation concept fundamentally distinct from traditional synthesis, synthetic microenvironment engineering features the core advantage of replacing macroscale rough operations with microscale precise regulation. Via three core dimensions-local physicochemical environment, spatial confinement effect, and external energy environment-it precisely manipulates the nucleation and growth processes, addressing the bottlenecks of conventional synthesis. Strategies across the three dimensions share the commonality of microscale regulation while possessing unique differentiated advantages; they can also be synergistically coupled to achieve controllable preparation of complex nanomaterials with uniform sizes and unique morphologies. This review focuses on microenvironment engineering strategies in nanomaterial synthesis, systematically summarizes the research progress of the three dimensions, compares the similarities and differences among various strategies, discusses their applications in hierarchical structure construction, crystal phase selection and surface modification, and analyzes the key challenges and future directions in fundamental research and industrial translation. It aims to provide a reference for the rational design, green synthesis and large-scale preparation of high-performance nanomaterials.