Due to their unique photocatalytic properties, nanostructured photocatalysts have shown broad prospects for application in environmental treatment. In recent years, researchers have significantly enhanced the photocatalytic charge separation efficiency and photocatalytic stability of photocatalysts by regulating semiconductor energy band structures, optimizing interface and surface properties, constructing heterogeneous structures, and introducing noble metal doping. This review systematically summarizes the basic principles, synthesis methods, and modification strategies of nanostructured photocatalysts and focuses on recent research advances in their environmental applications, such as water pollution control, air purification, and carbon dioxide reduction. Meanwhile, this review analyzes current challenges in the field, such as low quantum efficiency, insufficient stability, and limited industrialization, and outlines future development directions, including smart catalytic technology, fabrication of multifunctional composites, and large-scale synthesis, thereby providing a reference for research and application.

Nanoparticles leverage their unique nanoscale effects to optimize concrete performance through synergistic multi-mechanism interactions. Core mechanisms include micro-filling effects (graded pore filling, optimized pore structure), nucleation (promoting crystallization of hydration products, refining microstructure), chemical reactivity (e.g., pozzolanic reaction of nano-SiO₂, enhancing interfacial transition zones), and interfacial strengthening (improving ITZ structure and stress transfer). Common nanomaterials (e.g., nano-SiO₂, Al₂O₃, carbon nanotubes) significantly enhance concrete’s mechanical properties, durability, and functionalities (e.g., self-sensing, electromagnetic shielding). However, nano-modified concrete still faces challenges such as poor dispersion, high cost, and environmental/health risks. Future efforts should focus on multi-scale mechanism research, green low-cost synthesis processes, and intelligent composite systems development to advance the engineering applications pf nano-modified concrete.

With the rapid development of advanced machining technologies such as high-speed cutting, dry cutting, and ultra-precision cutting, as well as the widespread application of various difficult-to-machine materials, the surface degradation problems such as wear, oxidation, and delamination faced by tools in the service process have become increasingly prominent, seriously restricting the performance and service life of tools. Nanocoatings, with their distinct nano-effects, provide superior hardness, thermal stability, and tribological properties, making them an effective solution for cutting tools in increasingly demanding working environments. For example, the hardness of the CrAlN/TiSiN nano-multilayer coating can reach 41.59 GPa, which is much higher than that of a single CrAlN coating (34.5–35.8 GPa). This paper summarizes the most common nanocoating material design, coating deposition technologies, performance evaluation indicators, and characterization methods currently used in cutting tools. It also discusses how to improve nanocoating performance using modulation analysis of element content, coating composition, geometric structure, and coating thickness. Finally, this paper considers the future development of nanocoatings for cutting tools in light of recent research hotspots.

As a novel organic–inorganic hybrid porous crystalline material, metal–organic frameworks (MOFs) are ideal sensitive materials for detecting gases, antibiotics, and ions, owing to their ultra-high specific surface area, tunable pore structures, abundant active sites, and tailorable architectures. This review systematically summarizes the core structural features, preparation methods, and modification strategies of MOFs, elaborates on the adsorption and signal conversion mechanisms in target detection, and highlights typical applications, performance advantages, and practical scenarios of MOF-based sensors, clarifying their structure–activity relationships and performance differences from traditional semiconductor sensors. It further analyzes key challenges, including insufficient stability, poor conductivity, large-scale preparation difficulties, and real-sample interference, as well as industrialization bottlenecks such as batch-to-batch reproducibility, instrument integration, and high costs. Additionally, it supplements cross-field synergistic innovations and industrialization progress, and prospects future directions: function-oriented precise design, multifunctional composite optimization, portable intelligent devices, green large-scale synthesis, and standardization promotion. This review provides a comprehensive reference for advancing MOF-based detection research and applications in environmental monitoring, industrial safety, food safety, and healthcare.

The proliferation of antibiotic resistance urgently demands the development of novel non-antibiotic-dependent antimicrobial strategies. Metal–organic framework material ZIF-8, with its tunable structure and excellent biocompatibility, shows great promise in the field of photocatalytic antibacterial applications. However, pure ZIF-8 suffers from limitations such as a narrow light absorption range and high carrier recombination rates. Doping ZIF-8 with transition metals such as cobalt or copper, herein denoted as M-ZIF-8 (M=Co, Cu), can significantly broaden its photoresponsive spectrum, promote reactive oxygen species (ROS) generation, and enable controlled metal ion release, thereby enhancing antimicrobial performance. Nevertheless, the release of metal ions also introduces potential biotoxicity concerns, limiting practical applications. This paper systematically reviews the trade-off between the photocatalytic antibacterial mechanism and biotoxicity of metal-doped M-ZIF-8 (M=Co, Cu), focusing on material design principles, antibacterial pathways, toxicity manifestations and mechanisms, as well as optimization strategies for “enhancing efficacy while reducing toxicity.” It further proposes future research challenges and directions in mechanism elucidation, smart material development, standardization, and industrialization to advance the safe and efficient application of these materials in medical and environmental fields.

Civil engineering infrastructure suffers material degradation, shortened service life and high maintenance costs under harsh environments and natural aging, threatening public safety. Nanopolymer composites, featuring designable microstructures and excellent macroscopic properties, provide a revolutionary solution to improve the weather resistance and toughness of civil engineering materials. This paper systematically clarifies the modification mechanisms of nanocomposites, focusing on nanofiller–polymer matrix interfacial interactions (physical adsorption, chemical bonding) and their synergistic effects in enhancing environmental aging resistance (UV, corrosion, freeze–thaw) and mechanical performance (toughening, strengthening, dynamic load resistance). It summarizes the latest applications in nanomodified protective coatings, sealing/bonding materials and composite structural components, revealing the inherent “structure-property-application” relationships. Furthermore, this paper addresses core large-scale application challenges, including technical bottlenecks, performance evaluation limitations and economic/environmental barriers. Finally, future research directions are proposed, covering multifunctional intelligent materials, green development, interdisciplinary computational methods and standardized systems. This review offers an integrated perspective, providing theoretical guidance and practical references for advancing durable, resilient and sustainable civil engineering.