The Role of Anions in Metal Chalcogenide Oxygen Evolution Catalysis: Electrodeposited Thin Films of Nickel Sulfide as "Pre-catalysts"
The Role of Anions in Metal Chalcogenide Oxygen Evolution Catalysis: Electrodeposited Thin Films of Nickel Sulfide as "Pre-catalysts"
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DOI：
10.1021/acsenergylett.6b00084
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发表时间：
2016-07-01
影响因子：
22
通讯作者：
Mullins, C. Buddie
中科院分区：
文献类型：
--
作者：
Mabayoje, Oluwaniyi;Shoola, Ahmed;Mullins, C. Buddie
析氧催化剂由金属（Ni, Co, Fe）和镍基或硫族（P， S, Se）离子组成，是一类很有前途的电催化剂，用于析氧反应（OER），这是光电化学分解水的重要反应。以脉冲电沉积硫化镍为原料合成了一种镍基析氧催化剂。在碱性电解质（1 M KOH）中，该催化剂在相对较低的过电位320 mV下产生10 mA/cm(2)的电流密度。重要的是，我们发现硫化镍中的硫阴离子在电催化剂的活性形式下被耗尽，并且在水被氧化成氧的电位范围内，NiS被转化为无定形的氧化镍。因此，这种硫化镍的优越催化活性与活性催化剂中的硫阴离子无关，而是与金属硫化作为高活性氧化镍OER电催化剂前体的能力有关。由硫化镍衍生的氧化镍被发现是无定形的，具有相对较高的表面积，这两个因素先前已被证明在析氧电催化中是重要的。
Oxygen evolution catalysts composed of a metal (Ni, Co, or Fe) and a pnictide or chalcogenide (P, S, or Se) counterion are a promising class of electrocatalysts for the oxygen evolution reaction (OER), an important reaction for the photoelectrochemical splitting of water. We synthesized a nickel-based oxygen evolution catalyst derived from pulse-electrodeposited nickel sulfide. This catalyst was found to produce current densities of 10 mA/cm(2) at the relatively low overpotential of 320 mV in alkaline electrolyte (1 M KOH). Importantly, we found that the sulfur anion in the nickel sulfide is depleted in the active form of the electrocatalyst and that the NiS is converted into an amorphous nickel oxide in the potential range where water is oxidized to oxygen. The superior catalytic activity of this nickel sulfide is thus unrelated to the sulfur anions in the active catalyst but is instead related to the metal sulfide's ability to act as a precursor to a highly active nickel oxide OER electrocatalyst. The nickel oxide derived from nickel sulfide was found to be amorphous with a relatively high surface area, two factors that have been previously shown to be important in oxygen evolution electrocatalysis.