Decoupled water electrolysis (DWE) offers a unique strategy for green hydrogen production by separating the hydrogen and oxygen evolution reactions either in time or space, with the potential for integration to intermittent renewable energy sources. This review highlights the critical assessment of DWE, including the different components used and the operational strategies to accelerate the hydrogen economy. Special emphasis is placed on redox mediator engineering, catalyst innovation, membranes, and next‐generation cell architectures to overcome current limitations associated with conventional electrolyzers including efficiency, stability, and cost. The in silico approaches, including density functional theory and molecular dynamics‐driven parameter optimization can accelerate DWE by bridging the gap between lab‐scale technology development and industrial scale‐up, thereby facilitating the rise of DWE as one of the next‐generation technologies for green hydrogen production. A visionary roadmap is proposed, showing the pathway from proof‐of‐concept laboratory studies toward market deployment, with the aim of recognizing DWE as a cornerstone technology for a sustainable, low‐carbon hydrogen future. The review is conceptualized based on literature survey and identified research gaps.
Nickel, cobalt, and manganese are difficult to separate and purify using traditional recycling methods for end‐of‐life ternary cathode materials from lithium‐ion batteries. This study presents a facile approach that enables efficient lithium extraction (94.1%), while most of the Ni/Co/Mn (>91%) are converted into Mn‐doped CoNi 2 S 4 (Mn‐CoNi 2 S 4 ) without separating Ni/Co/Mn. Additionally, this method also transforms the graphene oxide (GO) into nitrogen‐doped graphene (NG), which acts as a support for Mn‐CoNi 2 S 4 . The prepared Mn‐CoNi 2 S 4 /NG can be repurposed as an effective catalyst for the methanol oxidation reaction (MOR), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR). The ORR half‐wave potential of Mn‐CoNi 2 S 4 /NG is 0.788 V, the OER potential is 1.475 V at 10 mA cm −2 , and the MOR potential is only 1.395 V at 100 mA cm −2 . The zinc–air batteries (ZABs) using Mn‐CoNi 2 S 4 /NG as the cathode exhibit high power densities, excellent reversibility, and cycling stability. Additionally, replacing OER with MOR results in methanol‐assisted ZABs, which offer superior energy efficiency and cycling stability. This study offers a novel method for effectively recycling valuable metals from retired lithium‐ion batteries for electrocatalysis.
Rechargeable magnesium batteries (RMBs) are promising for large‐scale energy storage due to their intrinsic safety and abundant resources, yet their development remains critically hindered by the scarcity of high‐performance cathodes. Conversion‐type cathodes offer high theoretical capacity via multi‐electron redox, but most rely solely on cationic redox, leading to sluggish kinetics, high activation barriers, and severe structural degradation from large volume changes. Here, we report a molecular anchoring strategy using an amine‐terminated hyperbranched polymer (AHP) as a multifunctional template. The terminal ‐NH 2 groups coordinate Co 2+ in situ, directing the formation of ultradispersed CoS 2 nanoclusters, while the AHP matrix uniformly permeates CoS 2 to form 3D flexible network that prevents nanocluster aggregation and provides elastic buffering to accommodate volumetric strain during conversion. Consequently, the CoS 2 ‐AHP cathode delivers a high reversible capacity of 167.3 mAh g −1 at 50 mA g −1 and retains capacity retention of 91.8% after 300 cycles at 200 mA g −1 . Crucially, ex situ characterizations confirm a synergistic reversible anion‐cation co‐redox mechanism involving Co 3+/2+ ↔ Co 0 and S 2 2− ↔ S 2− conversions. This work establishes a molecular anchoring strategy for anion‐rich conversion materials to synergistically boost reaction kinetics and maintain structural integrity, enabling high capacity and superior cycling stability, and offering new insight for high‐performance multivalent‐ion battery cathodes.
A series of Ag@NiX composite photocatalysts were successfully constructed via a chemical reduction strategy and applied to gas‐solid phase photocatalytic CO 2 reduction without additional photosensitizer using H 2 O as sacrificial agent. The introduction of Ag nanoparticles (Ag NPs) on a Ni‐MOF, namely [Ni 2 (tipe)(cca) 2 (H 2 O) 2 ] ·2DMF·2H 2 O ( NiX ) (tipe = 1,1,2,2‐ tetrakis (4‐(1H‐imidazol‐1‐yl)phenyl)ethene, H 2 cca = 4‐carboxycinnamic acid), effectively enhanced visible‐light absorption capability of the composites and promoted separation and migration of photogenerated charge carriers. Among the prepared samples, Ag@NiX‐2 exhibited optimal photocatalytic performance and achieved a CO production rate of 14.7 μmol g −1 in 5 h. In situ FT‐IR measurements revealed the formation of key intermediate *COOH during the CO 2 photoreduction process, thereby elucidating the reaction pathway. Theoretical calculations showed that an interfacial charge transfer occurs between Ag NPs and NiX in the Ag@NiX composite, thus reducing the reaction Gibbs free energy. This study offers a feasible approach for rational development of MOF‐based composite photocatalysts toward efficient photocatalytic CO 2 reduction.
Cost‐effective Zr‐based chloride electrolytes are attractive for practical all‐solid‐state lithium batteries, but their limited oxidative stability restricts their use with high‐voltage cathodes. Fluorine incorporation can enhance the high‐voltage stability of chloride electrolytes, yet the strong electrostatic interaction between F − and Li + and the kinetic limitations of conventional one‐step synthesis often compromise Li + transport and compositional homogeneity. Herein, we propose a two‐step synthesis strategy coupled with Zn/F co‐modification to regulate anion incorporation and local structural disorder in Li 2 ZrCl 6 ‐based electrolytes. This stepwise pathway promotes multicomponent solid‐state reactions, facilitates Cl/F anion co‐occupancy, and resolves the tradeoff between high‐voltage stability and ionic transport. The optimized composition achieves an improved overall performance including oxidation stability, mechanical deformability, and ion transport. When paired with high‐voltage LiCoO 2 cathodes, the optimized solid electrolyte enables a high discharge capacity, together with good rate capability and cycling performance. Interfacial analyses reveal that F‐containing species redistribute toward the cathode surface during cycling, forming a LiF‐rich cathode–electrolyte interphase that suppresses oxidative decomposition and maintains intimate solid–solid contact. This work provides an effective reaction pathway engineering strategy for developing high‐voltage‐compatible Zr‐based halide electrolytes through dual‐halogen chemistry and aliovalent cation modification.
