Abstract
The catalytically inactive components of a film have been converted, through an operando method of synthesis, to produce a catalyst for the reaction that the film is catalyzing. Specifically, thin films of molybdenum diselenide have been synthesized using a two-step wet-chemical method, in which excess sodium selenide was first added to a solution of ammonium heptamolydbate in aqueous sulfuric acid, resulting in the spontaneous formation of a black precipitate that contained molybdenum triselenide (MoSe3), molybdenum trioxide (MoO3), and elemental selenium. After purification and after the film had been drop cast onto a glassy carbon electrode, a reductive potential was applied to the precipitate-coated electrode. Hydrogen evolution occurred within the range of potentials applied to the electrode, but during the initial voltammetric cycle, an overpotential of 400 mV was required to drive the hydrogen-evolution reaction at a benchmark current density of 10 mA cm-2. The overpotential required to evolve hydrogen at the benchmark rate progressively decreased with subsequent voltammetry cycles, until a steady state was reached at which only 250 mV of overpotential was required to pass 10 mA cm-2 of current density. During the electrocatalysis, the catalytically inactive components in the as-prepared film were (reductively) converted to MoSe2 through an operando method of synthesis of the hydrogen-evolution catalyst. The initial film prepared from the precipitate was smooth, but the converted film was completely covered with pores 200 nm in diameter. The porous MoSe2 film was stable while being assessed by cyclic voltammetry for 48 h, and the overpotential required to sustain 10 mA cm-2 of hydrogen evolution increased by
| Original language | English |
|---|---|
| Pages (from-to) | 2866-2873 |
| Number of pages | 8 |
| Journal | ACS Catalysis |
| Volume | 4 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - Sep 5 2014 |
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Keywords
- hydrogen-evolution reaction
- mesoporous catalysts
- synthesis of group VI dichalcogenides
- synthesis of molybdenum diselenide
- wet-chemical synthesis of layered electrocatalysts
ASJC Scopus subject areas
- Catalysis
Cite this
Operando synthesis of macroporous molybdenum diselenide films for electrocatalysis of the hydrogen-evolution reaction. / Saadi, Fadl H.; Carim, Azhar I.; Velazquez, Jesus M.; Baricuatro, Jack H.; McCrory, Charles C L; Soriaga, Manuel P.; Lewis, Nathan S.
In: ACS Catalysis, Vol. 4, No. 9, 05.09.2014, p. 2866-2873.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Operando synthesis of macroporous molybdenum diselenide films for electrocatalysis of the hydrogen-evolution reaction
AU - Saadi, Fadl H.
AU - Carim, Azhar I.
AU - Velazquez, Jesus M.
AU - Baricuatro, Jack H.
AU - McCrory, Charles C L
AU - Soriaga, Manuel P.
AU - Lewis, Nathan S
PY - 2014/9/5
Y1 - 2014/9/5
N2 - The catalytically inactive components of a film have been converted, through an operando method of synthesis, to produce a catalyst for the reaction that the film is catalyzing. Specifically, thin films of molybdenum diselenide have been synthesized using a two-step wet-chemical method, in which excess sodium selenide was first added to a solution of ammonium heptamolydbate in aqueous sulfuric acid, resulting in the spontaneous formation of a black precipitate that contained molybdenum triselenide (MoSe3), molybdenum trioxide (MoO3), and elemental selenium. After purification and after the film had been drop cast onto a glassy carbon electrode, a reductive potential was applied to the precipitate-coated electrode. Hydrogen evolution occurred within the range of potentials applied to the electrode, but during the initial voltammetric cycle, an overpotential of 400 mV was required to drive the hydrogen-evolution reaction at a benchmark current density of 10 mA cm-2. The overpotential required to evolve hydrogen at the benchmark rate progressively decreased with subsequent voltammetry cycles, until a steady state was reached at which only 250 mV of overpotential was required to pass 10 mA cm-2 of current density. During the electrocatalysis, the catalytically inactive components in the as-prepared film were (reductively) converted to MoSe2 through an operando method of synthesis of the hydrogen-evolution catalyst. The initial film prepared from the precipitate was smooth, but the converted film was completely covered with pores 200 nm in diameter. The porous MoSe2 film was stable while being assessed by cyclic voltammetry for 48 h, and the overpotential required to sustain 10 mA cm-2 of hydrogen evolution increased by
AB - The catalytically inactive components of a film have been converted, through an operando method of synthesis, to produce a catalyst for the reaction that the film is catalyzing. Specifically, thin films of molybdenum diselenide have been synthesized using a two-step wet-chemical method, in which excess sodium selenide was first added to a solution of ammonium heptamolydbate in aqueous sulfuric acid, resulting in the spontaneous formation of a black precipitate that contained molybdenum triselenide (MoSe3), molybdenum trioxide (MoO3), and elemental selenium. After purification and after the film had been drop cast onto a glassy carbon electrode, a reductive potential was applied to the precipitate-coated electrode. Hydrogen evolution occurred within the range of potentials applied to the electrode, but during the initial voltammetric cycle, an overpotential of 400 mV was required to drive the hydrogen-evolution reaction at a benchmark current density of 10 mA cm-2. The overpotential required to evolve hydrogen at the benchmark rate progressively decreased with subsequent voltammetry cycles, until a steady state was reached at which only 250 mV of overpotential was required to pass 10 mA cm-2 of current density. During the electrocatalysis, the catalytically inactive components in the as-prepared film were (reductively) converted to MoSe2 through an operando method of synthesis of the hydrogen-evolution catalyst. The initial film prepared from the precipitate was smooth, but the converted film was completely covered with pores 200 nm in diameter. The porous MoSe2 film was stable while being assessed by cyclic voltammetry for 48 h, and the overpotential required to sustain 10 mA cm-2 of hydrogen evolution increased by
KW - hydrogen-evolution reaction
KW - mesoporous catalysts
KW - synthesis of group VI dichalcogenides
KW - synthesis of molybdenum diselenide
KW - wet-chemical synthesis of layered electrocatalysts
UR - http://www.scopus.com/inward/record.url?scp=84907780276&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84907780276&partnerID=8YFLogxK
U2 - 10.1021/cs500412u
DO - 10.1021/cs500412u
M3 - Article
VL - 4
SP - 2866
EP - 2873
JO - ACS Catalysis
JF - ACS Catalysis
SN - 2155-5435
IS - 9
ER -