International Collaborative Laboratory of 2D Materials for Optoelectronic Science & Technology of Ministry of Education, Engineering Technology Research Center for 2D Material Information Function Devices and Systems of Guangdong Province, College of Optoelectronic Engineering , Shenzhen University , Shenzhen 518060 , China.
Department of Chemistry , National University of Singapore , 3 Science Drive 3 , Singapore 117543 , Singapore.
ACS Appl Mater Interfaces. 2019 Sep 25;11(38):34862-34868. doi: 10.1021/acsami.9b08232. Epub 2019 Sep 10.
Extrinsically controlling the intrinsic activity and stability of two-dimensional (2D) semiconducting materials by substitutional doping is crucial for energy-related applications. However, an in situ transition-metal doping strategy for uniform and large-area chemical vapor deposited 2D semiconductors remains a formidable challenge. Here, we successfully synthesize highly uniform niobium-substituted tungsten disulfide (Nb-WS) monolayers, with a doping concentration of nearly 7% and sizes reaching 100 μm, through a metal dopant precursor route, using salt-catalyzed chemical vapor deposition (CVD). Our results reveal unusual effects in the structural, optical, electronic, and electrocatalysis characteristics of the Nb-WS monolayer. The Nb dopants readily induce a band restructuring effect, providing the most active site with a hydrogen adsorption energy of 0.175 eV and hence greatly improving its hydrogen evolution activity The combined advantages of the unusual physics and chemistry by in situ CVD doping technique open the possibility in designing 2D-material-based electronics and catalysts of novel functionalities.
通过取代掺杂来控制二维（2D）半导体材料的本征活性和稳定性对于能源相关应用至关重要。然而，对于大面积化学气相沉积（CVD）2D 半导体的均匀和大面积的原位过渡金属掺杂策略仍然是一个巨大的挑战。在这里，我们通过使用盐催化 CVD 的金属掺杂前体路线成功合成了高度均匀的铌取代的二硫化钨（Nb-WS）单层，其掺杂浓度接近 7%，尺寸达到 100 μm。我们的结果揭示了 Nb-WS 单层在结构、光学、电子和电催化特性方面的异常效应。Nb 掺杂剂容易引起能带重构效应，为最活跃的位点提供了 0.175 eV 的氢吸附能，从而大大提高了其析氢活性。通过原位 CVD 掺杂技术获得的不寻常物理和化学的综合优势为设计基于 2D 材料的电子和催化剂的新型功能开辟了可能性。
