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.

Semiconductor-based photo-redox catalysis offers a sustainable route for green organic synthesis, yet efficient C(sp3)-H bond oxidation remains challenging due to slow charge separation and limited surface reactivity. Here, we report a CsPCN (cesium doped polymeric carbon nitride)-Cs3Bi2Br9 heterojunction that promotes efficient charge separation while retaining strong hole oxidation capability of Cs3Bi2Br9 and superior oxygen and reactant activation ability of CsPCN. In situ experimental and theoretical studies confirm the photoelectron transfer pathway from Cs3Bi2Br9 to CsPCN driven by the interfacial electric field, empowering efficient spatial charge separation and high affinity and activation capability toward oxygen and reactants. As a result, the heterojunction exhibits efficient C(sp3)-H bond oxidation performance and broad substrate applicability under visible-light irradiation, achieving a conversion rate of ethylbenzene to acetophenone up to 8420 µmol g-1 h-1, 4.3 times higher than blank Cs3Bi2Br9 (1950 µmol g-1 h-1). This work demonstrates a rational heterostructure design strategy to couple charge separation with surface reactant activation for efficient lead-free perovskite based photocatalytic C(sp3)-H functionalization.

Cyclometallated rhodium(iii) complexes have been underexplored as photosensitisers due to their low-lying d-d excited states, which result in weak visible-light absorption and non-emissive properties, coupled with a modest heavy atom effect that limits reactive oxygen species (ROS) generation. In this work, a series of cyclometallated rhodium(iii) polypyridine complexes appended with two rhodamine units [Rh(N^C)2(bpy-diRho)](PF6)3 was rationally designed as Type I photosensitisers. These complexes exhibited intense absorption in the visible region and moderate rhodamine fluorescence in solution upon photoexcitation. Time-resolved transient absorption spectroscopy revealed a long-lived rhodamine-based triplet excited state as the lowest-lying excited state in this hybrid system, which is attributed to the presence of the rhodium(iii) centre and is responsible for ROS photosensitisation. Notably, these rhodium(iii) complexes efficiently generated superoxide anion (O2˙-) and hydroxyl (HO˙) radicals via the Type I pathway upon photoirradiation, likely via intramolecular electron transfer between the two adjacent excited rhodamine units within the complex to form radical cation and anion. Cellular colocalisation studies demonstrated that these complexes predominantly accumulated in mitochondria, where the photosensitised ROS triggered significant mitochondrial dysfunction, resulting in their outstanding photocytotoxicity under both normoxic and CoCl2-induced hypoxic conditions. Further mechanistic investigations revealed that the photoinduced mitochondrial ROS generation triggered cancer cell death via gasdermin D-mediated pyroptosis. This rhodium(iii)-dirhodamine system further explores the utilisation of rhodium(iii) complexes as phototheranostic agents and underscores their potential in this role.

Protecting hierarchical data via multi-level encryption and authenticating high-contrast touch traces represents an emerging frontier demanding technological innovation in molecular materials. Herein, via precise molecular interventions, three D-A-A' (donor-acceptor-acceptor) type aggregation induced emission (AIE)-active positional isomers (p-TPy, m-TPy, and o-TPy) are designed by varying the pyridine ring position in the acceptor. Their systematic investigation reveals key photophysical and structure-property insights, revealing their potential in advanced security and encryption. Positional modulation regulates electron-accepting strength and molecular packing, leading to red-shifted solid-state emission and influencing PLQY, transient PL, solvatochromism, and thermal stability as supported by crystal analysis and theoretical calculations. These stimuli-adaptive isomers address two critical challenges in advanced security systems. First, thermochromic luminescent materials (TLMs) exhibiting multiple temperature-dependent luminescent states are formulated as security inks by doping the para-isomer into phase-change matrices, enabling a multi-level security system. Second, a red-emissive, water-soluble amphiphilic fluorescent probe is obtained by functionalizing the para-isomer into a pyridinium emitter (p-TPyMe), capable of detecting latent fingerprints on diverse substrates and revealing level-3 ridge details with an exceptional contrast value of 5.39. These results demonstrate how molecular design in single chromophores translates into strategic AIE-active stimuli-adaptive positional isomers with intricate structure-property relationships, highlighting their potential for next-generation anti-counterfeiting, data encryption, and forensic technologies.

Photocatalytic production of hydrogen peroxide (H2O2) from seawater represents a sustainable approach for solar energy conversion. However, complex ionic composition hinders charge transport and accelerates catalyst degradation, undermining efficiency and posing a major challenge to the development of effective photocatalysts. Here, we explore the role of axial symmetry in stabilized β-ketoamine covalent organic frameworks (COFs) for efficient seawater photocatalysis. Three COFs with identical chemical compositions but distinct symmetries, uniaxial (1KtTb), meta-uniaxial (2KtTb), and meta-triaxial (3KtTb), were synthesized. Comprehensive experiments and theoretical analyses reveal that axial symmetry significantly influences light absorption, photocarrier recombination, and the energy barriers of key intermediate pathways (*OOH and *OH). The uniaxial symmetric framework exhibits a narrower bandgap, improved charge separation, and lower reaction barriers, enabling enhanced solar utilization and photocatalytic performance. In real seawater tests from the Zhoushan Sea, the uniaxial symmetric COF achieved record H2O2 production rates of 12 865.2 µmol g-1 h-1 under oxygen and 8557.4 µmol g-1 h-1 in air, with over 90% activity retained after 20 cycles and 30 days of immersion. Our results demonstrate the application potential of structural symmetry in photocatalysis and guide the design of marine-adapted COFs for efficient H2O2 synthesis and photoelectric conversion.

Lithium-oxygen (Li-O2) batteries offer ultrahigh theoretical energy density, but suffer from limited cycle life and high overpotentials, particularly in LiOH-based systems. While LiOH chemistry provides superior environmental tolerance compared to Li2O2 systems, the inherent four-electron redox process creates substantial charging overpotentials that compromise performance. Here, we tailor electrolyte activity to enable an efficient LiOH redox process by integrating 1-phenylpyrrolidine (PPD) as a redox mediator within an ionic liquid electrolyte. PPD possesses an optimal oxidation potential and stable p-π conjugation, enabling homogeneous chemical decomposition of LiOH and overcoming electrode-electrolyte contact limitations. The ionic liquid 1-propyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (C3C1im TFSI) is engineered to regulate water reactivity and maintain hydrogen-bond networks, thereby promoting selective LiOH formation over Li2O2 during discharge, while providing high oxidative stability to suppress mediator degradation-an issue prevalent in ether-based electrolytes. This electrolyte-mediator synergy shifts the charging mechanism from sluggish interfacial charge transfer to a fast, solution-mediated chemical route, delivering 180 stable cycles with markedly reduced overpotentials and ∼10× longer cycle life. This work offers molecular-level design principles for tailoring electrolyte activity to achieve high-efficiency and durable Li-O2 batteries based on LiOH chemistry.

The scalable production of hydrogen through electrochemical water splitting demands earth-abundant catalysts with both high activity and dynamic tunability, yet achieving these attributes simultaneously remains a major challenge. Two-dimensional (2D) ferroelectric materials offer a unique opportunity, as their reversible polarization can modulate surface electronic states, though their potential in electrocatalysis has scarcely been explored. Here, we employ first-principles calculations to investigate the electronic structure and hydrogen evolution reaction (HER) activity of recently synthesized Cu n (CrSe2) n+1 (n = 1-3) monolayers with tunable thickness and robust multiferroic behavior at room temperature. We identify surface Se top sites as the optimal catalytic centers, with the down-polarized state exhibiting HER activity comparable to that of benchmark Pt(111). A strong inverse correlation between hydrogen adsorption free energy and the p-band center of surface Se atoms is further established, providing a predictive descriptor for catalyst design. Crucially, reversible polarization dynamically modulates hydrogen adsorption energetics through charge redistribution, enabling efficient transitions between H adsorption and H2 desorption and thereby maximizing HER efficiency. These insights position Cu n (CrSe2) n+1 as a promising polarization-switchable platform for high-performance and controllable electrocatalysis, offering general design principles for next-generation ferroelectric catalysts.

Noncentrosymmetric (NCS) crystalline materials are indispensable for nonlinear optical (NLO) applications, yet their rational design remains challenging due to thermodynamic preferences for centrosymmetric configurations. Herein, we demonstrate a halogen-driven strategy for obtaining NCS structures by leveraging competitive coordination between halide anions (X-) and stereochemically active Sn2+ centers. Precise halogen substitution induced the formation of two new polymorphs of [N(C2H5)4]SnBr3 (Cc and Cmc21 phase) using different halide sources (i.e., [N(C2H5)4]Cl or [N(C2H5)4]Br). Compared to the Cc phase (2 × KH2PO4), the resulting Cmc21 phase exhibits exceptional second-harmonic generation (SHG) efficiency (5.6 × KH2PO4). This performance ranks among the highest for all reported Sn-based organic-inorganic hybrid NLO materials to date. Theoretical calculations indicate that the [SnBr3]- unit is the primary source of the strong SHG response. This work establishes halogen-driven symmetry control as a viable strategy for achieving a dramatically enhanced SHG response, thereby providing a valuable reference for the rational design of high-performance NLO materials.

The stereoselective functionalisation of alkenyl P(v) compounds via conjugate additions represents an attractive approach to synthesise chiral organophosphorus compounds. However, asymmetric conjugate additions to alkenyl P(v) compounds are scarce and, in the presence of P-stereogenic centers, diastereoinduction is often low. Here, we report the use of BINOL-based alkenylphosphonium salts for the generation of two non-consecutive P- and C-stereogenic centers via addition of C-nucleophiles in a single operation. These alkenylphosphonium salts behave as activated alkenylphosphonamidate surrogates with increased reactivity and stereocontrol. This methodogy allows the versatile preparation of enantioenriched organophosphorus building-blocks in high yield and stereoselectivity.

Chemical ligation is an essential tool for constructing complex biomolecular architectures. To accelerate reaction discovery, a one-pot multi-substrate screening (OPMSS) platform was developed, combining peptide nucleic acid (PNA) tagging with direct MALDI analysis. This approach enables the simultaneous evaluation of multiple substrate pairs in a single pot without the need for chromatographic separation. Short PNA tags promote a uniform combinatorial pairing of substrates while the neutral polyamide backbone facilitates MALDI analysis to allow direct readout of ligated products as predominantly singly charged ions. Using this system, we readily detected established ligations, including Huisgen cycloaddition and amide bond formation, validating the platform in pilot screens pairing 8 × 8 substrates (64 possible combinations). Applying the method to discovery-mode screening of 13 × 11 substrates under visible-light photocatalytic conditions identified a previously unexplored ligation between alkyl azides and alkenes, consistent with pathways involving aminyl radicals or aminium radical cations. This work demonstrates the potential of OPMSS with PNA tagging as a practical and discovery-oriented approach for identifying new ligation reactions directly from complex mixtures.