Search

Designing high-performance, cost-effective, and durable electrocatalysts for hydrogen evolution reactions is essential and challenging. The design of electrode surface architecture to accomplish rapid gas bubble release is a promising strategy. Herein, we design a unique network-structured catalyst by constructing NiFe alloy on a submicron carbon fiber network substrate (NiFe/SCFN). The unique structure imparts superaerophobicity to NiFe/SCFN and facilitates gas bubbles removal, thereby accelerating mass transfer. Benefiting from electrode alloying, the hydrogen adsorption free energy was reduced to − 0.026 eV (Fe sites) and 0.077 eV (Ni sites) on the catalyst surface, improving the electronic conductivity. NiFe/SCFN achieves low overpotentials of 19.2 mV and 199 mV at 10 mA∙cm−2 and 100 mA∙cm−2 with excellent stability, owing to the unique network structure and the NiFe alloy's electronic structure. This work provides a new strategy for designing effective catalysts with transition metals. [Display omitted] • The unique network structure endows the catalyst superaerophobic characteristics. • The hydrogen adsorption free energy is reduced to ‐0.026 eV (Fe sites) and 0.077 eV (Ni sites). • NiFe/SCFN delivers an ultra-low overpotential (19.2 mV @10 mA∙cm‐2) and shows excellent stability. [ABSTRACT FROM AUTHOR]

Soil ecosystem multifunctionality (EMF), the ability of an ecosystem to perform multiple functions, remains uncertain in its contribution to crop production, especially in the context of long-term fertilization ecosystems. This study was carried out on a 40-year-old long-term fertilization experiment in black soil in China. Soil samples were collected from four treatments: control (CK); nitrogen (N) fertilizer; phosphorus (P) fertilizer; and a combination of nitrogen and phosphorus (NP) in both maize and wheat planting seasons. The results showed significant effects of N, P fertilizers and crop season on soil biotic and abiotic properties, especially on soil enzyme activities. Crop productivity and soil EMF showed a similar pattern across different treatments and both crop seasons, with significant higher values recorded in treatments with N addition (i.e. N and NP). Soil EMF was strongly associated with crop productivity in both maize and wheat seasons, while soil pH had a negative impact on crop yield. Random forest analysis revealed that microbial functional gene structure was significantly correlated with both soil ecosystem multifunctionality and crop yield. This suggested that fertilization leads to alterations in soil nutrients and the composition of functional microbial communities, subsequently impacting ecological functions and crop growth. These findings indicated that mineral fertilizers can enhance crop yield through soil EMF in the black soils, while exerted substantial impact on soil properties, raising concerns about the sustainability of soils under continuous chemical fertilization. • Long-term mineral fertilization improves soil ecosystem multifunctionality. • Soil ecosystem multifunctionality is strongly associated with crop productivity. • Soil pH and nitrate were the dominant variables in determining soil ecosystem multifunctionality. • Functional gene community structure had significant correlation with crop production. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe/N co-doped porous hydrochar by various synthesis schemes is used to remove Cr(VI). • Modified hydrochar shows excellent properties owing to Fe0 and heterocyclic‑N. • Porous activation facilitates the loading and dispersion of Fe particle on hydrochar. • The maximum adsorption capacity of MP 1 HC MW for Cr(VI) reaches 274.34 mg/g. • Adsorption, reduction, complexation, and precipitation are benefit to Cr(VI) removal. Four kinds of Fe/N co-doped porous hydrochar were prepared by one/two-step N-doping schemes using microwave/traditional pyrolysis methods for removing Cr(VI) from aqueous phase. Heterocyclic-N was introduced through CO(NH 2) 2 -based hydrothermal carbonization process, which could adjust the electronic structure of the hydrochar framework. Furthermore, Fe0 and Fe 3 O 4 were embedded into hydrochar via carbothermal reduction reaction using FeCl 3 as the precursor, which improved the reducibility and magnetism of the material. The modified hydrochar exhibited pH-dependency and rapid kinetic equilibrium, and the maximal adsorption amount of magnetic porous hydrochar obtained by microwave-assisted one-step N-doping (MP 1 HC MW) reached 274.34 mg/g. Meanwhile, the modified hydrochar had a high tolerance to multiple co-existing ions and the removal efficiency maintained above 73.91 % during five regeneration cycles. Additionally, MP 1 HC MW efficiently removed Cr(VI) via pore filling, electrostatic attraction, ion exchange, reduction, complexation, and precipitation. Summarily, Fe/N co-doped porous hydrochar was a feasible adsorbent with outstanding remediation potential for Cr(VI)-contaminated water. [ABSTRACT FROM AUTHOR]