This study presents a strategy to enhance the oxygen evolution reaction (OER) kinetics on metal-organic frameworks (MOFs) by optimizing bond lengths through acid etching. The developed catalyst, AE-CoNDA, is based on Co-naphthalenedicarboxylic acid and demonstrates excellent OER activity with a low overpotential of 260 mV to reach 10 mA cm⁻² and a small Tafel slope of 62 mV dec⁻¹. When integrated with BiVO₄, AE-CoNDA achieves a photocurrent density of 4.3 mA cm⁻² at 1.23 V under AM 1.5G irradiation, outperforming most reported Co-based BiVO₄ photoanodes. The stretched Co–O bond length in AE-CoNDA optimizes the hybridization of Co 3d and O 2p orbitals, facilitating efficient water splitting. Theoretical calculations show that the optimized bond length enhances the adsorption of oxygen-containing intermediates at the Co active sites, leading to improved OER performance. The study also reveals that the spin state transition from an intermediate spin to a high spin state in AE-CoNDA enhances the orbital hybridization and reaction kinetics. The AE-CoNDA catalyst exhibits long-term stability and high durability, making it a promising candidate for efficient and durable OER electrocatalysts. The results highlight the importance of bond length optimization in enhancing the catalytic activity of MOFs for water splitting applications.This study presents a strategy to enhance the oxygen evolution reaction (OER) kinetics on metal-organic frameworks (MOFs) by optimizing bond lengths through acid etching. The developed catalyst, AE-CoNDA, is based on Co-naphthalenedicarboxylic acid and demonstrates excellent OER activity with a low overpotential of 260 mV to reach 10 mA cm⁻² and a small Tafel slope of 62 mV dec⁻¹. When integrated with BiVO₄, AE-CoNDA achieves a photocurrent density of 4.3 mA cm⁻² at 1.23 V under AM 1.5G irradiation, outperforming most reported Co-based BiVO₄ photoanodes. The stretched Co–O bond length in AE-CoNDA optimizes the hybridization of Co 3d and O 2p orbitals, facilitating efficient water splitting. Theoretical calculations show that the optimized bond length enhances the adsorption of oxygen-containing intermediates at the Co active sites, leading to improved OER performance. The study also reveals that the spin state transition from an intermediate spin to a high spin state in AE-CoNDA enhances the orbital hybridization and reaction kinetics. The AE-CoNDA catalyst exhibits long-term stability and high durability, making it a promising candidate for efficient and durable OER electrocatalysts. The results highlight the importance of bond length optimization in enhancing the catalytic activity of MOFs for water splitting applications.