The development of a green and sustainable process for electrochemical ammonia synthesis has a significant impact on modern society in terms of agricultural and industrial development, as well as energy reform. The electrocatalytic nitrogen reduction reaction (NRR) has been regarded as a promising strategy and the efficiency of the NRR strongly depends on electrocatalysts with excellent activity, selectivity, and stability. Metal sulfides have been regarded as potential electrocatalysts due to the “accept and back-donate” interaction of metals with N₂. In addition, it has been proposed that both the intrinsic and extrinsic catalytic activity, selectivity and stability of metal sulfides can be improved through defect and interface engineering. In this review, the recent progress on metal sulfides toward the NRR is summarized based on defect and interface engineering. The typical synthetic methods, physicochemical properties, and catalytic performances of the catalysts are outlined to provide insights into the structure–performance relationship of the catalysts. In particular, the origin of the outstanding NRR catalytic activity, selectivity and stability was revealed from both experimental and theoretical perspectives. Furthermore, the remaining challenges and future perspectives are presented with the aim of providing insightful guidance for developing more efficient NRR electrocatalysts.

Two novel fluorinated covalent organic frameworks as drug carriers with good biocompatibility were developed, showing excellent drug loading capacity and sustained release in vitro .

The fluorescence of an imidazolium macrocycle can be switched from monomer emission to aggregate emission in the presence of pyrophosphate anion and zinc ion, which can be used as a ratiometric fluorescence sensor for pyrophosphate anion in water.

A fluorescent porous organic polymer (FPOP) with strong fluorescence and tunable emission colors, was synthesized through a simple cost-effective method via Scholl coupling reaction. Experiments proved the stability and excellent detection and adsorption ability, and microporous nature of the material. Luminescence of FPOP was quenched when addition of nitroaromatic compounds. The properties along with large-scale and low-cost preparation make these FPOP potential candidates for fluorescence detection of nitroaromatic compounds. Additionally, FPOP shows higher adsorption capacity and rate than other reported adsorbents, and has the possibility of being an effective adsorbent for industrial usage. Moreover, a fluorescent test paper was further developed and is found to be sensitive to 10^–8 M level, complete with a rapid response time and visual detection. This newly developed strategy may open up an avenue for exploring porous polymers, particularly those with a strong fluorescence, for the large-scale fabrication of FPOP for various advanced applications.

MOF (metal organic framework) materials have been used as functional materials in a number of fields due to their diverse spatial tunability, which produces rich porous structures with stable and continuous pores and a high specific surface area. A triboelectric nanogenerator can convert trace mechanical energy into electrical energy, and the application of MOF materials to triboelectric nanogenerators has been intensively studied. In this work, we report on two MOFs with similar spatial structures, and the modulation of the end microstructures was achieved using the difference in F content. The output performance of friction power generation increases with the increase in F content, and the obtained polyacidic ligand materials can be used to construct self-powered corrosion protection systems, which can effectively protect metallic materials from corrosion.

The emergence of nanogenerators, which have the ability to capture mechanical energy from the environment and to collect and transmit tiny energy, is rapidly becoming a hot research topic. The performance of electrode materials is the key to the efficiency of nanogenerators. Covalent organic skeletons (COFs), a class of crystalline organic porous materials with the advantages of large specific surface area, high porosity, tunable structure, and flexible tailorability, have very significant advantages in being used as nanogenerator materials. In this paper, we synthesised two COF materials to investigate the effect of the introduction of active metals on the friction power generation performance of COFs without changing their topology, COF-2 containing zinc ions is capable of generating a short-circuit current of 107.5 µA during friction. The porous structure increases the effective contact area to form a larger charge density, and the introduction of metal ions can accelerate the charge separation and transport. The two bidirectional synergistic effects of the materials significantly improve the output performance of the nanogenerator, and a simple and efficient method is explored for the enhancement of the output performance of COF-based triboelectric nanogenerators.