Heteroatom-doped carbon is widely used in the fields of adsorbents, electrode materials and catalysts due to its excellent physicochemical properties. N and S co-doped porous carbon spheres (N,S-PCSs) were synthesized using glucose and L-cysteine as carbon and heteroatom sources using a combined hydrothermal and KOH activation process. The physicochemical structures and single-factor methylene blue (MB) adsorption properties of the N,S-PCSs were then studied. The optimized N,S-PCSs-1 possessed a perfect spherical morphology with a 2–8-μm diameter and a large specific area of 1769.41 m² g⁻¹, in which the N and S contents were 2.97 at% and 0.88 at%, respectively. In the single-factor adsorption experiment for MB, the MB adsorption rate increased with an increase in carbon dosage and MB initial concentration, and the adsorption reached equilibrium within 2–3 h. The pseudo-second-order kinetic model could excellently fit the experimental data with a high R² (0.9999). The Langmuir isothermal adsorption equation fitted well with the experimental results with an R² value of 0.9618, and the MB maximum adsorption quantity was 909.10 mg g⁻¹. The adsorption of MB by N,S-PCSs-1 was a spontaneous, endothermic, and random process based on the thermodynamics analyses. The adsorption mechanism mainly involved Van der Waals force adsorption, π-π stacking, hydrogen bonds and Lewis acid–base interactions.

Exploring efficient and robust self‐supporting hydrogen evolution reaction (HER) electrodes using simple, accessible, and low‐cost synthetic processes is crucial for the commercial application of water electrolysis at high current densities. Ni‐based self‐supporting electrodes are widely studied owing to their low cost and good catalytic performance. However, to date, the preparation of Ni‐based electrodes requires multistep and complex preparation processes. In this study, a novel one‐step in situ sintering method to synthesize mechanically stable and highly active Ni₃Se₂‐Ni electrodes with well‐controlled morphologies and structures is developed. Their excellent performance and durability can be attributed to the numerous highly active nano‐Ni₃Se₂ catalysts embedded on the surface of the Ni skeleton, the excellent conductivity of the interconnected conductive network, and the strong interfacial bonding between Ni₃Se₂ and Ni. As a result, the Ni₃Se₂‐Ni600 electrode can operate stably at 85 and 400 mA cm⁻² for more than 800 and 300 h, respectively. Moreover, the Ni₃Se₂‐Ni600 electrode displays outstanding stability for over 500 h in a commercial two‐electrode system. This study provides a feasible one‐step synthesis method for low‐cost, high‐efficiency metal selenide‐metal self‐supporting electrodes for water electrolysis.

Lithium-sulfur batteries are anticipated to be the next generation of energy storage devices because of their high theoretical specific capacity. However, the polysulfide shuttle effect of lithium-sulfur batteries restricts their commercial application. The fundamental reason for this is the sluggish reaction kinetics between polysulfide and lithium sulfide, which causes soluble polysulfide to dissolve into the electrolyte, leading to a shuttle effect and a difficult conversion reaction. Catalytic conversion is considered to be a promising strategy to alleviate the shuttle effect. In this paper, a CoS₂-CoSe₂ heterostructure with high conductivity and catalytic performance was prepared by in situ sulfurization of CoSe₂ nanoribbon. By optimizing the coordination environment and electronic structure of Co, a highly efficient CoS₂-CoSe₂ catalyst was obtained, to promote the conversion of lithium polysulfides to lithium sulfide. By using the modified separator with CoS₂-CoSe₂ and graphene, the battery exhibited excellent rate and cycle performance. The capacity remained at 721 mAh g⁻¹ after 350 cycles, at a current density of 0.5 C. This work provides an effective strategy to enhance the catalytic performance of two-dimensional transition-metal selenides by heterostructure engineering.