Journal of Colloid and Interface Science最新文献

Rechargeable magnesium-ion batteries (RMBs) demonstrate notable benefits, including higher theoretical energy density, cost-effectiveness, and improved safety characteristics, positioning them as a viable substitute for conventional energy storage solutions. Nevertheless, the ongoing development of high-performance RMBs continues to face inevitable challenges, such as unsatisfactory practical capacity, inadequate cycle durability, swift energy degradation, and a comparatively limited-service life. Herein, CoS/NiS nanomaterials with cubic-shaped morphology were prepared by a two-step metal sulfide template-free solvothermal synthesis method. The material with internal cavity structure effectively mitigates the large expansion of magnesium-ion battery cathode material due to Mg²⁺ embedding during the charging and discharging process, and provides a robustness electrode-electrolyte interface, thus greatly improving the cycle life. Besides, the introduction of Ni elements into CoS materials may form heterojunctions thereby lowering the potential barrier of the conversion reaction and improving the reaction kinetics and redox reversibility. In addition, the abundance of highly electronegative SS bonds in the CoS/NiS material, which also provides many electrochemically active sites and smooth transport paths for the embedding of Mg²⁺, leads to the reduction of its polarization and the improvement of its reaction kinetics, which makes the CoS/NiS as a RMBs cathode material with a high specific capacity and a long cycling life. Thus, this research presents a feasible and effective strategy for enhancing the Mg²⁺ storage capability of engineered CoS nanomaterials, with potential applicability and adaptability to other electrode materials.

Conventional urea industry faces dual challenges of high energy consumption and carbon emissions. Although electrochemical co-reduction of nitrates and carbon dioxide (CO₂) offers a promising route for green urea synthesis, its electrical-to-chemical energy conversion efficiency remains constrained by sluggish reaction kinetics and high electrical energy demand. Here, we design and report a nitrogen-doped porous carbon (NC) material embedded with dispersed copper‑nickel bimetal nanoparticles (CuNi/NC) for constructing the first example of a Zn-nitrate/CO₂ battery that can output electricity while generating urea with a superior energy efficiency of 1.51 mol_urea kWh^-1 and a urea production rate of 110 mg h^-1 g_cat^-1. The proposed assembled battery exhibits exceptional stability over 300 h, retaining high urea Faradaic efficiency at 36% and yield at 100.9 mg h^-1 g_cat^-1. In situ X-ray absorption spectroscopy, infrared spectroscopy, and density functional theory simulations confirm that the active metal sites facilitate substrate adsorption and stabilize critical intermediates (*N-C-N, *NH₂, and *NO), thereby effectively accelerating CN coupling. This work breaks the 'high-energy, single-function' bottleneck of traditional electrochemical systems, establishing an innovative 'carbon-negative energy supply' paradigm for carbon-neutral agriculture and decentralized energy systems.

Excessive reactive oxygen species (ROS) drive oxidative stress and disease progression, yet the structural determinants of antioxidant activity in carbon dots (CDs) remain unclear. In this study, the influence of oxygenated surface functional groups and carbon hybridization states on the performance of saccharide-derived CDs was elucidated. CDs were synthesized from five saccharide precursors via hydrothermal carbonization, and synthesis parameters were systematically optimized using response surface methodology combined with central composite design (200-240 °C, 6-12 h). Among the tested precursors, xylose yielded CDs (X-CDs) with the smallest size (2.17-4.38 nm), the strongest blue emission (427-450 nm), the highest negative surface charge (-38.5 to -84.6 mV), and the highest quantum yield (0.80-2.81%). Spectroscopic analyses revealed enriched oxygen functionalities (O/C ratio up to 0.32) and graphitic sp² domains with reduced sp³ content, correlating with enhanced electronic delocalization. Optimized X-CDs exhibited potent radical scavenging activity (EC₅₀ = 0.047 mg/mL for DPPH; 0.008 mg/mL for ABTS) while showing low cytotoxicity toward normal and cancer cells. These findings establish a mechanistic framework linking oxygenated groups and sp² hybridization to enhanced antioxidant properties and provide a green, tunable strategy for designing high-performance CDs from renewable precursors for biomedical, nutraceutical, and environmental applications.