Molybdenum disulfide (MoS₂) has emerged as a promising material for catalysis and sustainable energy conversion. However, the inertness of its basal plane to electrochemical reactions poses challenges to the utilization of wafer-scale MoS₂ in electrocatalysis. To overcome this limitation, we present a technique that enhances the catalytic activity of continuous MoS₂ by preferentially activating its buried grain boundaries (GBs). Through mild UV irradiation, a significant enhancement in GB activity was observed that approaches the values for MoS₂ edges, as confirmed by a site-selective photo-deposition technique and micro-electrochemical hydrogen evolution reaction (HER) measurements. Combined spectroscopic characterization and ab-initio simulation demonstrates substitutional oxygen functionalization at the grain boundaries to be the origin of this selective catalytic enhancement by an order of magnitude. Our approach not only improves the density of active sites in MoS₂ catalytic processes but yields a new photocatalytic conversion process. By exploiting the difference in electronic structure between activated GBs and the basal plane, homo-compositional junctions were realized that improve the photocatalytic synthesis of hydrogen by 47% and achieve performances beyond the capabilities of other catalytic sites.

中文翻译：

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选择性激活 MoS2 晶界以增强电化学活性

二硫化钼（MoS ₂）已成为一种有前途的催化和可持续能源转换材料。然而，其基面对电化学反应的惰性给晶圆级MoS ₂在电催化中的应用带来了挑战。为了克服这一限制，我们提出了一种通过优先激活其埋藏晶界（GB）来增强连续MoS ₂催化活性的技术。通过温和的紫外线照射，观察到 GB 活性显着增强，接近 MoS ₂边缘的值，这已通过位点选择性光沉积技术和微电化学析氢反应 (HER) 测量证实。结合光谱表征和从头算模拟表明，晶界处的替代氧功能化是这种选择性催化增强一个数量级的根源。我们的方法不仅提高了MoS ₂催化过程中活性位点的密度，而且产生了一种新的光催化转化过程。通过利用活化GBs和基面之间电子结构的差异，实现了同质组成连接，将氢的光催化合成提高了47%，并实现了超越其他催化位点能力的性能。