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Nitrate (NO3−), a nitrogen-containing pollutant, is prevalent in aqueous solutions, contributing to a range of environmental and health-related issues. The electrocatalytic reduction of NO3− holds promise as a sustainable approach to both eliminating NO3− and generating valuable ammonia (NH3). Nevertheless, the reduction reaction of NO3− (NO3−RR), involving 8-electron transfer process, is intricate, necessitating highly efficient electrocatalysts to facilitate the conversion of NO3− to NH3. In this study, Fedoped Co3O4 nanowire strutted three-dimensional (3D) pinewood-derived carbon (Fe-Co3O4/PC) is proposed as a high-efficiency NO3−RR electrocatalyst for NH3 production. Operating within 0.1 M NaOH containing NO3−, Fe-Co3O4/PC demonstrates exceptional performance, obtain an impressively large NH3 yield of 0.55 mmol·h−1·cm−2 and an exceptionally high Faradaic efficiency of 96.5% at −0.5 V, superior to its Co3O4/PC counterpart (0.2 mmol·h−1·cm−2, 73.3%). Furthermore, the study delves into the reaction mechanism of Fe-Co3O4 for NO3−RR through theoretical calculations. [ABSTRACT FROM AUTHOR]

Electrochemical nitrate (NO3−) reduction is a sustainable pathway for ambient ammonia (NH3) synthesis while eliminating NO3− pollutants in water. However, the NO3− reduction reaction (NO3−RR) involves a complicated eight-electron transfer process, which needs highly selective and efficient electrocatalysts. This work describes the synthesis of Fe3O4 nanoparticle-decorated 3D pinewood-derived carbon (Fe3O4/PC) as a high-efficiency catalyst for the electroreduction of NO3− to NH3 at ambient reaction conditions. When tested in 0.1 M NaOH containing 0.1 M NO3−, the Fe3O4/PC obtains a large NH3 yield of 394.8 μmol h−1 cm−2 and high faradaic efficiency (FE) of 91.6% at −0.4 V. Significantly, Fe3O4/PC also delivers high stability. [ABSTRACT FROM AUTHOR]

Silicon-based anode materials are considered as the most attractive alternatives to traditional graphite anodes, thereby advancing the evolution of new-generation lithium-ion battery technology. However, the inadequate electrical conduction of silicon-based materials, along with severe volume expansion during charging and discharging processes, limits their further technological applications. Herein, a dual-layer carbon shell configuration is designed to efficiently alleviate the substantial volumetric expansion of silicon during cycles, while simultaneously improving the efficiency of both electron and lithium ions. The effectiveness of this layered buffering approach is credited to the networked structure of outer single-walled carbon nanotubes (SWCNTs) layer, which is firmly attached to the inner carbon shell's surface. The modified structure not only elevates the level of electrical conduction, but also significantly reduces the internal stress due to silicon's expansion. The developed Si@C@SWCNT electrode materials exhibit high capacity of 1267.3 mA h g−1 after 500 cycles at 1 A g−1, and sustains an elevated rate capacity of 863 mA h g−1 at 8 A g−1. This study highlights the enormous potential of Si@C@SWCNT composites for use in lithium-ion batteries and provides new perspectives for further exploration and utilization of silicon-carbon anodes. • SWCNTs anchoring on the outer layer of Si@C via electrostatic self-assembly. • Long-term cycling stability: 1267.3 mA h g−1 at 1 A g−1 after 500 cycles. • High-rate performance: 834 mA h g−1 at 8 A g−1. • Thin layered SWCNT webbing anchoring to carbon improves structural stability. • The anchoring between SWCNTs and carbon shell enhances the Li + transport. [ABSTRACT FROM AUTHOR]