Molecule-based solid-state materials with room temperature phosphorescence (RTP) are playing an increasingly important role in developing optical sensors, security systems, and biological imaging. However, molecular systems involving long-lived persistent RTP are still rare to date, which has limited the efficiently luminescent recognition and identification. Herein, it is illustrated that the RTP properties of molecular phosphors can be highly enhanced based on coordination interaction with common metal (such as Zn²⁺). These molecule–metal hybrids present tunable afterglow phosphorescence by adjusting metal species and stacking fashions of molecular units, with the longest RTP lifetime of 1.3 s. Such long-lived persistent emission decay is higher than most of currently reported molecule-based and molecule–metal solid-state RTP systems. Moreover, the reversible phosphorescence transformation under different pH and heat conditions can be further switched and recycled. This work therefore offers a cost-effective and facile way to achieve high-performance RTP metal-organic hybrid materials, which could serve as promising candidates for noble-metal-free and rare-earth-free phosphors in illumination and sensor applications.

Molecule-based micro-/nanomaterials have attracted considerable attention because their properties can vary greatly from the corresponding macro-sized bulk systems. Recently, the construction of multicomponent molecular solids based on crystal engineering principles has emerged as a promising alternative way to develop micro-/nanomaterials. Unlike single-component materials, the resulting multicomponent systems offer the advantages of tunable composition, and adjustable molecular arrangement, and intermolecular interactions within their solid states. The study of these materials also supplies insight into how the crystal structure, molecular components, and micro-/nanoscale effects can influence the performance of molecular materials. In this review, we describe recent advances and current directions in the assembly and applications of crystalline multicomponent micro-/nanostructures. Firstly, the design strategies for multicomponent systems based on molecular recognition and crystal engineering principles are introduced. Attention is then focused on the methods of fabrication of low-dimensional multicomponent micro-/nanostructures. Their new applications are also outlined. Finally, we briefly discuss perspectives for the further development of these molecular crystalline micro-/nanomaterials.

The development of new semiconductor photocatalysts toward splitting water has supplied a promising way to obtain sustainable and clean hydrogen energy. Herein, CdZnS@layered double hydroxide (LDH) composites with a hierarchical flower-like microstructure have been fabricated with the aid of ZnCr–LDH nanosheets as templates. XRD, SEM and HRTEM show that the ZnCr–LDH nanosheets are uniformly dispersed within the composites. The surface of the hierarchical structures is rough and composed of numerous nanocrystals of CdZnS. The HRTEM images indicate that the surface of CdZnS nanocrystals is mainly composed of the (111) plane. Moreover, the visible-light-driven H₂ production performance of the CdZnS in the presence and absence of ZnCr–LDH nanosheets has been measured. The results show that ZnCr–LDH nanosheets play an important role in the hierarchical morphology and photocatalytic activity of the as-prepared samples. In the water-splitting process, the visible-light-driven H₂-production rate of hierarchical flower-like CdZnS@LDH is 4.03 times and nearly 10 times higher than that of pristine CdZnS microsphere and pure commercial CdS, respectively. Therefore, this work not only achieves enhanced catalytic performance of the CdZnS by the introduction of ZnCr–LDH nanosheets, but also supplies an insight into the relationship between the hierarchical morphology and the semiconductor photocatalytic activity.