Hydrothermally synthesized nickel molybdenum selenide composites as cost-effective and efficient trifunctional electrocatalysts for water splitting reactions

• Published in: International journal of hydrogen energy 2019-08, Vol.44 (41), p.22796-22805
• Main Authors: Premnath, Kumar, Arunachalam, Prabhakarn, Amer, Mabrook S., Madhavan, Jagannathan, Al-Mayouf, Abdullah M.
• Format: Article
• Language: English
• Subjects: Electrocatalysis; Hydrogen evolution reaction; Nickel selenides; Oxygen evolution reaction; Renewable energy
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2019.07.034

The development of efficient, cost-effective routes to prepare non-platinum-based electrocatalysts is a significant scientific challenge in water-splitting systems. A multifunctional electrocatalyst for the hydrogen evolution, oxygen evolution, and oxygen reduction reactions (HER/OER/ORR) involved in the water-splitting process was fabricated using a simple and eco-friendly strategy. The present study involves the simple synthesis of nanostructured nickel selenide (NiSe) via a hydrothermal method. The different phases of nickel selenide and their dependency on the precursor concentration were analyzed using X-ray diffraction (XRD). The morphologies of coral-like structured pure and Mo-doped NiSe (Ni1-xMoxSe) samples were investigated systematically using scanning electron microscopy (SEM). The as-prepared Ni0.5Mo0.5Se material showed an enhanced electrochemical activity of 1.57 V @ 10 mA/cm2 for OER and 0.19 V @ 10 mA/cm2 to HER, and follows the Volmer-Heyrovsky for HER mechanism. In addition, the electrocatalyst exhibits a large electrochemical surface area and high stability. Therefore, the hydrothermally synthesized Ni1–xMoxSe has been proven to be a perfect platinum-free trifunctional electrocatalyst for water splitting process. [Display omitted] •Molybdenum doped NiSe materials for HER, OER and ORR have been studied.•The composition Ni0.5Mo0.5Se has shown enhanced electrochemical activities.•Enhanced electrochemical active surface area of Ni0.5Mo0.5Se was measured to be 1.201 mF/cm2.•The optimized composite was found to follow the Volmer-Heyrovsky mechanism.