Reaction time-controlled Ni-BTC MOF for sustainable hydrogen evolution catalyst

Designing efficient and robust electrocatalysts is essential for sustainable hydrogen production via water electrolysis. In this work, a reaction time-controlled, morphology-tailored Ni-BTC MOF, synthesized over 12 hours, is developed as an effective electrocatalyst for the HER. Powder X-ray diffraction confirms the formation of the crystalline framework with preserved coordination between Ni 2+ centers and trimesic acid linkers, along with reduced crystallite size. The Ni–BTC MOF exhibits a mesoporous architecture with a high surface area of 204.77 m 2 g -1 , facilitating enhanced electrolyte accessibility and mass transport. Morphological and compositional analyses using FESEM, TEM, and EDS further confirm the formation of a uniform porous structure. Electrochemical studies reveal that the optimized 9:0.5:0.5 electrode exhibits a low overpotential of 170 mV at 10 mA cm -2 and a Tafel slope of 120 mV dec -1 , along with excellent durability over prolonged operation. The enhanced double-layer capacitance (3.12 × 10 -3 F) and electrochemically active surface area (78.1 cm 2 ) indicate a higher density of accessible active sites compared to the 8:1:1 electrode. These results demonstrate that reaction time-controlled morphological tuning and optimized electrode composition significantly enhance HER performance, highlighting Ni-BTC MOF as promising candidates for efficient and sustainable hydrogen generation. • Reaction time-controlled synthesis of morphology-tuned Ni-BTC MOF. • High surface area (204.77 m² g⁻¹) enhances HER activity • Ni–BTC (12 h) electrode exhibits a low overpotential of 170 mV at 10 mA cm⁻². • Tafel slope of 120 mV dec⁻¹ indicates favourable HER kinetics. • Excellent stability over 3600 min in a two-electrode system.