Revealing the contribution of π-π stacking interactions in supramolecular assembly is important for understanding the intrinsic nature of molecular assembly fundamentally. However, because they are much weaker than covalent bonds, π-π stacking interactions are usually ignored in the construction of porous materials. Obtaining stable porous materials that are only dependent on π-π stacking interactions, despite being very challenging, could address this concern. Here, we present a porous supramolecular framework (π-1) stabilized only by intermolecular π-π stacking interactions. π-1 shows good thermal and chemical stability not only in various organic solvents but also in aqueous solution in a broad pH range. Furthermore, featuring one-dimensional channels with dangling thiolate groups, π-1 exhibits excellent Hg²⁺ removal performance, with adsorption capacity as high as 786.67 mg g⁻¹ and an adsorption ratio as high as 99.998%. In addition, π-1 also shows high adsorption selectivity to Hg²⁺ in the presence of a series of interfering ions.

Hydrogen-bonded organic frameworks (HOFs), a new type of porous material following the metal–organic frameworks (MOFs), covalent organic frameworks (COFs), etc., have emerged as one of the promising candidates in diverse potential applications. In this highlight, we summarize the key progress on HOF-based materials, in which their design, structures, as well as potential applications will be discussed.

The development of readily available, highly efficient and stable electrocatalysts for the oxygen evolution reaction (OER) is extremely significant to facilitate water splitting for the generation of clean hydrogen energy. Layered double hydroxides (LDHs) exhibit promising electrocatalytic performance for the OER. However, their electrical conductivity and active sites should be increased for the preparation of more effective OER electrocatalysts based on LDHs for large-scale applications. Herein, we demonstrate a facile and practical pathway for the hierarchical fabrication of three-dimensional (3D) porous sulphur incorporated NiCoFe LDH nanosheets (S-NiCoFe LDH) on carbon cloth (CC). The as-obtained hierarchically structured S-NiCoFe LDH electrode shows superb electrocatalytic activity and stability for the OER, requiring overpotentials as low as 206 mV and 258 mV to achieve current densities of 10 mA cm⁻² and 100 mA cm⁻² in 1.0 M KOH solution, respectively, making S-NiCoFe LDH one of the most efficient low-cost electrocatalysts for the OER. The enhanced electrocatalytic performance is attributed to the unique 3D hierarchical nanostructure and sulphur doping, which endow the self-supported S-NiCoFe LDH electrode with abundant active sites and superb electrical conductivity. The strategy expands the possibilities for boosting the catalytic activity of LDH-based OER electrocatalysts.

Catalysts featuring dinuclear metal sites are regarded as superior systems compared with their counterparts with mononuclear metal sites. The dinuclear metal sites in catalysts with appropriate spatial separations and geometric configurations can confer the dinuclear metal synergistic catalysis (DMSC) effect, and thus boost the catalytic performance, in particular for reactions involving multiple reactants, intermediates and products. In this review, we summarize the related reports on the design and synthesis of both homogeneous and heterogeneous dinuclear metal catalysts, and their applications in energy conversion reactions, including photo-/electro-catalytic hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), CO₂ reduction reaction (CO₂RR), and N₂ reduction reaction (N₂RR). Particularly, we focus on the analysis of the relationship between the catalyst structure and catalytic performances, where the design principles are presented. Finally, we discuss the challenges in the design and preparation of dinuclear metal catalysts with the DMSC effect and present a perspective on the future development of dinuclear metal catalysts in energy conversion. This review aims to comprehensively summarize the up-to-date research progress on the synthesis and energy-related application of dinuclear metal catalysts and provide guidance for designing energy-conversion catalysts with superior performances.