State Research Institute Centre for Physical Sciences and Technology, Savanoriu Ave. 231, LT-02300 Vilnius, Lithuania.
Vilnius University, Faculty of Physics, Sauletekio Ave. 9, LT-10222 Vilnius, Lithuania.
Sci Rep. 2016 Nov 28;6:37514. doi: 10.1038/srep37514.
One-pot hydrothermal synthesis of MoS nanoplatelet arrays on various substrates is perhaps the most promising approach to fabricate efficient electrocatalysts for hydrogen evolution reaction. However, the main challenges in this synthesis remain the purity and crystallinity of MoS. In this study, we show for the first time that irradiation of amorphous, defect-rich MoS nanoplatelets with a green nanosecond laser at a proper irradiation dose, ca ≤0.35 J cm, can significantly improve the crystallinity and purity of MoS nanoplatelets. The effect was confirmed by Raman spectroscopy investigations demonstrating a surprising intensity increase of the A and modes after the laser irradiation. Further increase of irradiation energy, however, resulted in the photocorrosion and destruction of MoS nanoplatelets. The variation of A and Raman mode intensities ratio depending on the green light irradiation dose was also presented and is discussed below.
在各种基底上采用一锅水热合成法制备 MoS 纳米薄片阵列可能是制备高效析氢反应电催化剂最有前途的方法。然而，这种合成方法仍然存在一些主要的挑战，包括 MoS 的纯度和结晶度。在这项研究中，我们首次表明，用适当剂量的绿色纳秒激光（约 0.35 J/cm²）辐照非晶态、富含缺陷的 MoS 纳米薄片，可以显著提高 MoS 纳米薄片的结晶度和纯度。拉曼光谱研究证实了这一效果，表明激光辐照后 A 和 E 模的强度惊人地增加。然而，进一步增加辐照能量会导致 MoS 纳米薄片的光腐蚀和破坏。还提出了 A 和 Raman 模强度比随绿光辐照剂量的变化，并在下面进行了讨论。
