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The efficient conversion and storage of solar energy for chemical fuel production presents a challenge in sustainable energy technologies. Metal nitrides (MNs) possess unique structures that make them multi‐functional catalysts for water splitting. However, the thermodynamic instability of MNs often results in the formation of surface oxide layers and ambiguous reaction mechanisms. Herein, we present on the photo‐induced reconstruction of a Mo‐rich@Co‐rich bi‐layer on ternary cobalt‐molybdenum nitride (Co3Mo3N) surfaces, resulting in improved effectiveness for solar water splitting. During a photo‐oxidation process, the uniform initial surface oxide layer is reconstructed into an amorphous Co‐rich oxide surface layer and a subsurface Mo−N layer. The Co‐rich outer layer provides active sites for photocatalytic oxygen evolution reaction (POER), while the Mo‐rich sublayer promotes charge transfer and enhances the oxidation resistance of Co3Mo3N. Additionally, the surface reconstruction yields a shortened Co−Mo bond length, weakening the adsorption of hydrogen and resulting in improved performance for both photocatalytic hydrogen evolution reaction (PHER) and POER. This work provides insight into the surface structure‐to‐activity relationships of MNs in solar energy conversion, and is expected to have significant implications for the design of metal nitride‐based catalysts in sustainable energy technologies. [ABSTRACT FROM AUTHOR]

The optimized VN-2 composite exhibits an impressive high-rate capacity and ultra-long lifespan for zinc-ion batteries in all-climate conditions (-15–50 °C) achieved by the Zn2+ intercalation and conversion storage mechanism. [Display omitted] • The VN shows a high capacity of 272 mAh g−1 after 7000 cycles at 5 A g−1. • The ex-situ results disclose the Zn2+ intercalation and conversion storage mechanism. • It shows remarkable performance for AZIBs in all-climate conditions (-15–50 °C). Rechargeable aqueous zinc-ion batteries have great promise for becoming next-generation storage systems, although the irreversible intercalation of Zn2+ and sluggish reaction kinetics impede their wide application. Therefore, it is urgent to develop highly reversible zinc-ion batteries. In this work, we modulate the morphology of vanadium nitride (VN) with different molar amounts of cetyltrimethylammonium bromide (CTAB). The optimal electrode has porous architecture and excellent electrical conductivity, which can alleviate volume expansion/contraction and allow for fast ion transmission during the Zn2+ storage process. Furthermore, the CTAB-modified VN cathode undergoes a phase transition that provides a better framework for vanadium oxide (VO x). With the same mass of VN and VO x , VN provides more active material after phase conversion due to the molar mass of the N atom being less than that of the O atom, thus increasing the capacity. As expected, the cathode displays an excellent electrochemical performance of 272 mAh g−1 at 5 A g−1, high cycling stability up to 7000 cycles, and excellent performance over a wide temperature range. This discovery creates new possibilities for the development of high-performance multivalent ion aqueous cathodes with rapid reaction mechanisms. [ABSTRACT FROM AUTHOR]