In-situ optimizing the valence configuration of vanadium sites in NiV-LDH nanosheet arrays for enhanced hydrogen evolution reaction

•Well-integrated in-NiV-LDH/NF nanosheet arrays were synthesized via facile hydrothermal method.•High proportion trivalent vanadium effectively tuned the valence configuration of in-NiV-LDH/NF.•The optimized valence configuration enhanced the HER kinetics and thus reduced the required overpotentials.•In-NiV-LDH/NF nanosheet exhibited robust HER durability in both alkaline and neutral media.