Selective two-electron (2e⁻) oxygen reduction reaction (ORR) offers great opportunities for hydrogen peroxide (H₂O₂) electrosynthesis and its widespread employment depends on identifying cost-effective catalysts with high activity and selectivity. Main-group metal and nitrogen coordinated carbons (M-N-Cs) are promising but remain largely underexplored due to the low metal-atom density and the lack of understanding in the structure-property correlation. Here, we report using a nanoarchitectured Sb₂S₃ template to synthesize high-density (10.32 wt%) antimony (Sb) single atoms on nitrogen- and sulfur-codoped carbon nanofibers (Sb-NSCF), which exhibits both high selectivity (97.2%) and mass activity (114.9 A g⁻¹ at 0.65 V) toward the 2e⁻ ORR in alkaline electrolyte. Further, when evaluated with a practical flow cell, Sb-NSCF shows a high production rate of 7.46 mol g_catalyst⁻¹ h⁻¹ with negligible loss in activity and selectivity in a 75-h continuous electrolysis. Density functional theory calculations demonstrate that the coordination configuration and the S dopants synergistically contribute to the enhanced 2e⁻ ORR activity and selectivity of the Sb-N₄ moieties.

Bimetallic phosphides have been identified as promising alternative electrode materials owing to their admirable conductivity and electrochemical activity. Nevertheless, the severe agglomeration of single-component bimetallic phosphides hinders their extensive applications. Moreover, current research lacks in-depth studies on the effect of outer/inter-component synergy on the rate capability. In this study, novel nickel cobalt phosphide nanowires on two-dimensional graphene oxide nanosheets (GO@NiCoP) were designed and prepared by combining a hydrothermal process and phosphorization. GO served as the conductive path to improve the composite conductivity and provided abundant oxygen-containing functional groups to coordinate with the metal cations of NiCoP, thereby boosting the overall structural stability. NiCoP possesses an optimal intercomponent synergistic effect, such as an optimal –OH⁻ adsorption energy and deprotonation energy, leading to an enhanced potential of the electrochemical reaction. Taking advantage of these materials, the GO@NiCoP electrode displayed a high specific capacitance of 1125 F g⁻¹ (155 mA h g⁻¹) at 2 A g⁻¹ and a high cycling stability of 104.88% capacitance retention after 5000 cycles at 30 A g⁻¹. Interestingly, the GO@NiCoP electrode delivered an exceptional rate capability of 84.09% capacitance retention at 20 A g⁻¹ and 39.77% capacitance retention at 60 A g⁻¹ owing to its stable structure and excellent conductivity. In addition, we fabricated a GO@NiCoP//AG ASC device that delivered a desirable energy density of 27.71 W h kg⁻¹ at 788 W kg⁻¹. To broaden its applications, a self-charging power system with a satisfactory lighting time was constructed using the ASC device. In short, the outstanding electrochemical performance of the electrode materials provides a novel perspective for enhancing the rate capacity of electrode materials by the outer/inter-component synergistic effect.

Conversion into high-value-added organic nitrogen compounds through electrochemical C-N coupling reactions under ambient conditions is regarded as a sustainable development strategy to achieve carbon neutrality and high-value utilization of harmful substances. Herein, we report an electrochemical process for selective synthesis of high-valued formamide from carbon monoxide and nitrite with a Ru₁Cu single-atom alloy under ambient conditions, which achieves a high formamide selectivity with Faradaic efficiency of 45.65 ± 0.76% at −0.5 V vs. RHE. In situ X-ray absorption spectroscopy, coupled with in situ Raman spectroscopy and density functional theory calculations results reveal that the adjacent Ru-Cu dual active sites can spontaneously couple *CO and *NH₂ intermediates to realize a critical C-N coupling reaction, enabling high-performance electrosynthesis of formamide. This work offers insight into the high-value formamide electrocatalysis through coupling CO and NO₂⁻ under ambient conditions, paving the way for the synthesis of more-sustainable and high-value chemical products.

Many industrial wastewater streams contain heavy metals, posing serious and irreversible damage to humans and living organisms, even at low concentrations due to their high toxicity and persistence in the environment. In this study, high-performance monodispersed chitosan (CS) microspheres were prepared using a simple microfluidic method and evaluated for metal removal from contaminated water. Batch experiments were carried out to evaluate the adsorption characteristics for the removal of copper ions, one representative heavy metal, from aqueous solutions. The inherent advantages of microfluidics enabled a precise control of particle size (CV = 2.3%), while exhibiting outstanding selectivity towards target ions (adsorption capacity 75.52 mg g-1) and fair regeneration (re-adsorption efficiency 74% after 5 cycles). An integrated adsorption mechanism analytic system was developed based on different adsorption kinetics and isotherms models, providing an excellent adsorption prediction model with pseudo-second order kinetics (R2 = 0.999), while the isotherm was fitted best to the Langmuir model (R2 = 0.998). The multi-step adsorption process was revealed via quantitative measurements and schematically described. Selective adsorption performance of CS microspheres in the present of other competitive metal ions with different valence states has been demonstrated and studied by both experimental and density functional theory (DFT) analysis.