Materials that recover dilute metals and convert the recovered species into functional catalysts can link resource circularity with environmental remediation, yet their design is constrained by a trade-off between rapid transport and reactive binding. Here, we report a ZIF−8-derived hollow N-doped porous carbon (HNPC) as a capture-to-catalyst platform for closed-loop gold recovery and nitrate-to-ammonia electrocatalysis. The hollow mesoporous framework shortens diffusion pathways and improves access to internal surfaces, whereas graphitic-N-associated sites promote AuCl₄⁻ adsorption and Au(III)-to-Au(0) reduction. The optimized HNPC exhibits a Langmuir Au(III) capacity of 3245.1 mg·g^-1 and removes >99.9% of Au at trace concentrations under strong ionic competition, corresponding to a distribution coefficient of ~3×10⁹ mL·g⁻¹. Time‑resolved microscopy and spectroscopy reveal rapid Au nanoparticle nucleation and progressive conversion to Au(0), while finite−element simulations and density functional theory (DFT) identify the cooperative roles of hollow-structure-enabled transport and graphitic-N-regulated interfacial reactivity. The resulting Au/HNPC is directly reused as a gas-diffusion-electrode catalyst, delivering 96.6% Faradaic efficiency for nitrate-to-ammonia conversion and stable operation for 535 h at 200 mA·cm⁻²_. This work establishes a materials strategy for integrating selective recovery, in situ metal formation, and catalytic reuse in complex aqueous media.

The overuse and ineffective management of plastics have led to significant environmental pollution. Catalytic upcycling into value-added chemicals has emerged as a promising solution. This review provides a comprehensive overview of recent advances in catalytic upcycling, focusing on the cleavage of chemical bonds such as carbon–carbon (C–C), carbon–oxygen (C–O), and carbon–hydrogen (C–H) in plastics. It systematically discusses plastics conversion via electrocatalysis, thermal catalysis, and photocatalysis. Additionally, it explores the conversion of plastics into value-added chemicals and functional polymers. The review also addresses the challenges in this field and aims to offer insights for developing sustainable and effective plastics upcycling technologies.

The coupling of energy-saving small molecule conversion reactions and hydrogen evolution reaction (HER) in seawater electrolytes can reduce the energy consumption of seawater electrolysis and mitigate chlorine corrosion issues. However, the fabrication of efficient multifunctional catalysts for this promising technology is of great challenge. Herein, a heterostructured catalyst comprising CoP and Ni₂P on nickel foam (CoP/Ni₂P@NF) is reported for hydrazine oxidation (HzOR)-assisted alkaline seawater splitting. The coupling of CoP and Ni₂P optimizes the electronic structure of the active sites and endows excellent electrocatalytic performance for HzOR and HER. Impressively, the two-electrode HzOR-assisted alkaline seawater splitting (OHzS) cell based on the CoP/Ni₂P@NF required only 0.108 V to deliver 100 mA·cm⁻², much lower than 1.695 V for alkaline seawater electrolysis cells. Moreover, the OHzS cell exhibits satisfactory stability over 48 h at a high current density of 500 mA·cm⁻². Furthermore, the CoP/Ni₂P@NF heterostructured catalyst also efficiently catalyzed glucose oxidation, methanol oxidation, and urea oxidation in alkaline seawater electrolytes. This work paves a path for high-performance heterostructured catalyst preparation for energy-saving seawater electrolysis for H₂ production.

As an ideal carbon-free energy carrier, ammonia plays an indispensable role in modern society. The conventional industrial synthesis of NH₃ by the Haber–Bosch technique under harsh reaction conditions results in serious energy consumption and environmental pollution. Therefore, it is essential to develop NH₃ synthesis tactics under benign conditions. Electrochemical synthesis of NH₃ has the advantages of mild reaction conditions and environmental friendliness, and has become a hotspot for research in recent years. It has been reported that zinc-nitrogen batteries (ZNBs), such as Zn-N₂, Zn-NO, Zn-NO₃⁻, and Zn-NO₂⁻ batteries, can not only reduce nitrogenous species to ammonia but also have concomitant power output. However, the common drawbacks of these battery systems are unsatisfactory power density and ammonia production. In this review, the latest progress of ZNBs including the reaction mechanism of the battery and reactor design principles is systematically summarized. Subsequently, active site engineering of cathode catalysts is discussed, including vacancy defects, chemical doping, and heterostructure engineering. Finally, some insights are provided to improve the performance of ZNBs from a practical perspective of view.