title: Microwave-Initiated Facile Formation of Ni3Se4Nanoassemblies for Enhanced and Stable Water Splitting in Neutral and Alkaline Media.
abstract: Molecular hydrogen (H2) generation through water splitting with minimum energy loss has become practically possible due to the recent evolution of high-performance electrocatalysts. In this study, we fabricated, evaluated, and presented such a high-performance catalyst which is the Ni3Se4nanoassemblies that can efficiently catalyze water splitting in neutral and alkaline media. A hierarchical nanoassembly of Ni3Se4was fabricated by functionalizing the surface-cleaned Ni foam using NaHSe solution as the Se source with the assistance of microwave irradiation (300 W) for 3 min followed by 5 h of aging at room temperature (RT). The fabricated Ni3Se4nanoassemblies were subjected to catalyze water electrolysis in neutral and alkaline media. For a defined current density of 50 mA cm-2, the Ni3Se4nanoassemblies required very low overpotentials for the oxygen evolution reaction (OER), viz., 232, 244, and 321 mV at pH 14.5, 14.0, and 13.0 respectively. The associated lower Tafel slope values (33, 30, and 40 mV dec-1) indicate the faster OER kinetics on Ni3Se4surfaces in alkaline media. Similarly, in the hydrogen evolution reaction (HER), for a defined current density of 50 mA cm-2, the Ni3Se4nanoassemblies required low overpotentials of 211, 206, and 220 mV at pH 14.5, 14.0, and 13.0 respectively. The Tafel slopes for HER at pH 14.5, 14.0, and 13.0 are 165, 156, and 128 mV dec-1, respectively. A comparative study on both OER and HER was carried out with the state-of-the-art RuO2and Pt under identical experimental conditions, the results of which revealed that our Ni3Se4is a far better high-performance catalyst for water splitting. Besides, the efficiency of Ni3Se4nanoassemblies in catalyzing water splitting in neutral solution was carried out, and the results are better than many previous reports. With these amazing advantages in fabrication method and in catalyzing water splitting at various pH, the Ni3Se4nanoassemblies can be an efficient, cheaper, nonprecious, and high-performance electrode for water electrolysis with low overpotentials.
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR), CSIR-Central Electrochemical Research Institute (CSIR-CECRI) Campus , New Delhi, India.
authors.forename: Sengeni
authors.identifier: http://orcid.org/0000-0002-3265-2455
authors.initials: S
authors.lastname: Anantharaj
authors.forename: Jeevarathinam
authors.initials: J
authors.lastname: Kennedy
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR), CSIR-Central Electrochemical Research Institute (CSIR-CECRI) Campus , New Delhi, India.|Department of Materials Science and Mechanical Engineering, Texas A&M University , College Station, Texas 77843, United States.
authors.forename: Subrata
authors.identifier: http://orcid.org/0000-0002-1992-9659
authors.initials: S
authors.lastname: Kundu
keywords: Ni3Se4 nanoassemblies; Tafel analysis; electrolysis; hydrogen evolution; overpotential; oxygen evolution; water splitting