Nickel Sulfides as Competent Hydrogen Evolution Catalysts in Water
Location
Eccles Conference Center Auditorium
Event Website
http://water.usu.edu
Start Date
3-31-2015 9:50 AM
End Date
3-31-2015 10:00 AM
Description
Solar-driven water splitting to produce hydrogen and oxygen is widely considered as a sustainable approach to meet the increasing global energy demands, in which hydrogen acts as a green energy carrier. The slow kinetics of hydrogen evolution reaction (HER) in water necessitates the development of competent and low-cost HER catalysts. Recently we found that nickel-sulfide (Ni-S) films prepared by potentiodynamic deposition exhibited excellent HER catalysis over a wide range of pH values. A current density of 60 mA/cm2 can be achieved within an overpotential of 550 mV with a Tafel slope of 77 mV/dec at pH 7. The remarkable stability of the Ni-S films is manifested in the steady current of a 100 h controlled potential electrolysis in neutral aqueous media or even in natural water. A suite of materials characterization techniques revealed the major composition of the Ni-S films was Ni3S2, which preserved during the electrocatalysis of hydrogen evolution. It is known that other nickel sulfides, such as NiS2 and NiS, show active HER catalysis. In order to gain a deeper understanding on the composition-structure-performance relationships, we set out to investigate the intrinsic HER catalytic properties of three nickel sulfides: Ni3S2, NiS2, and NiS. Crystalline nanoparticles of these three nickel sulfides were synthesized by microwave-assisted methods. Electrochemical data coupled with characterization results unambiguously prove that Ni3S2 possesses the best HER catalytic performance among the three investigated nickel sulfide nanoparticles.
Nickel Sulfides as Competent Hydrogen Evolution Catalysts in Water
Eccles Conference Center Auditorium
Solar-driven water splitting to produce hydrogen and oxygen is widely considered as a sustainable approach to meet the increasing global energy demands, in which hydrogen acts as a green energy carrier. The slow kinetics of hydrogen evolution reaction (HER) in water necessitates the development of competent and low-cost HER catalysts. Recently we found that nickel-sulfide (Ni-S) films prepared by potentiodynamic deposition exhibited excellent HER catalysis over a wide range of pH values. A current density of 60 mA/cm2 can be achieved within an overpotential of 550 mV with a Tafel slope of 77 mV/dec at pH 7. The remarkable stability of the Ni-S films is manifested in the steady current of a 100 h controlled potential electrolysis in neutral aqueous media or even in natural water. A suite of materials characterization techniques revealed the major composition of the Ni-S films was Ni3S2, which preserved during the electrocatalysis of hydrogen evolution. It is known that other nickel sulfides, such as NiS2 and NiS, show active HER catalysis. In order to gain a deeper understanding on the composition-structure-performance relationships, we set out to investigate the intrinsic HER catalytic properties of three nickel sulfides: Ni3S2, NiS2, and NiS. Crystalline nanoparticles of these three nickel sulfides were synthesized by microwave-assisted methods. Electrochemical data coupled with characterization results unambiguously prove that Ni3S2 possesses the best HER catalytic performance among the three investigated nickel sulfide nanoparticles.
https://digitalcommons.usu.edu/runoff/2015/2015Posters/27