Affiliation:
1. Advanced Materials and Devices Laboratory (AMDL) Department of Nanoscience and Technology Bharathiar University Coimbatore, Tamilnadu 641046 India
2. Sustainable and Responsive Manufacturing Group Faculty of Mechanical and Manufacturing Engineering Technology Universiti Teknikal Malaysia Melaka Hang Tuah Jaya Melaka, Malacca 76100 Malaysia
3. Defence Metallurgical Research Laboratory (DMRL) Defence Research and Development Organisation (DRDO) Hyderabad 500058 India
4. Department of Physics Dongguk University 30 Pildong-ro 1 gil, Jung-gu Seoul 04620 Republic of Korea
Abstract
AbstractCobalt phosphides have been investigated as potentially useful electrocatalysts for accelerating hydrogen evolution. Cobalt phosphide electrocatalysts are synthesized in a single step at varied phosphating temperatures (350, 400, 450 °C) via the gas phase approach. Synthesized at a phosphating temperature of 350 °C, Co2P (CP‐350) transforms into a mixed phase that contains both Co2P and CoP (CP‐400 and CP‐450) as the phosphating temperature goes up which is confirmed by XRD. CP‐350, CP‐400, and CP‐450 exhibited overpotentials of 181, 270, and 293 mV respectively with Tafel slopes of 112, 146, and 175 mV/dec. In contrast to CP‐400 and CP‐450, CP‐350 revealed superior hydrogen evolution reaction (HER) performance and stability for up to 12 h due to its pure phase (Co2P), high surface area (151 m2/g), and high electrochemical surface area (7.02 cm2) with low charge transfer resistance. According to our work, changing the phase and active surface area of transition metal phosphide catalysts can greatly increase their HER catalytic efficiency.