Shin Seokhee, Jin Zhenyu, Kwon Do Hyun, Bose Ranjith, Min Yo-Sep
Department of Chemical Engineering, Konkuk University , 120 Neungdong-Ro, Gwangjin-Gu, Seoul 143-701, Korea.
Langmuir. 2015 Jan 27;31(3):1196-202. doi: 10.1021/la504162u. Epub 2015 Jan 9.
Recently amorphous MoS2 thin film has attracted great attention as an emerging material for electrochemical hydrogen evolution reaction (HER) catalyst. Here we prepare the amorphous MoS2 catalyst on Au by atomic layer deposition (ALD) using molybdenum hexacarbonyl (Mo(CO)6) and dimethyl disulfide (CH3S2CH3) as Mo and S precursors, respectively. Each active site of the amorphous MoS2 film effectively catalyzes the HER with an excellent turnover frequency of 3 H2/s at 0.215 V versus the reversible hydrogen electrode (RHE). The Tafel slope (47 mV/dec) on the amorphous film suggests the Volmer-Heyrovsky mechanism as a major pathway for the HER in which a primary discharging step (Volmer reaction) for hydrogen adsorption is followed by the rate-determining electrochemical desorption of hydrogen gas (Heyrovsky reaction). In addition, the amorphous MoS2 thin film is electrically evaluated to be rather conductive (0.22 Ω(-1) cm(-1) at room temperature) with a low activation energy of 0.027 eV. It is one of origins for the high catalytic activity of the amorphous MoS2 catalyst.
最近，非晶态MoS₂薄膜作为一种用于电化学析氢反应（HER）催化剂的新兴材料受到了广泛关注。在这里，我们通过原子层沉积（ALD），分别使用六羰基钼（Mo(CO)₆）和二甲基二硫醚（CH₃S₂CH₃）作为Mo和S前驱体，在Au上制备了非晶态MoS₂催化剂。非晶态MoS₂薄膜的每个活性位点都能有效地催化HER，在相对于可逆氢电极（RHE）为0.215 V时，具有3 H₂/s的优异周转频率。非晶态薄膜上的塔菲尔斜率（47 mV/dec）表明Volmer-Heyrovsky机制是HER的主要途径，其中氢吸附的主要放电步骤（Volmer反应）之后是氢气的速率决定电化学解吸（Heyrovsky反应）。此外，非晶态MoS₂薄膜经电学评估具有相当高的导电性（室温下为0.22 Ω⁻¹ cm⁻¹），活化能低至0.027 eV。这是非晶态MoS₂催化剂高催化活性的原因之一。
