Capped Vapor−Liquid−Solid Growth of Vanadium-Substituted MoS₂ Ultrathin Films for Enhanced Photocatalytic Activity
以封蓋式氣-液-固成長法製備釩摻雜二硫化鉬超薄膜以提升光觸媒活性——應用於二氧化碳光觸媒還原
📄 英文摘要
This work reports a SiO₂-capped vapor−liquid−solid (VLS) growth method that assists in substituting vanadium into molybdenum disulfide ultrathin film and introducing sulfur vacancies to form Svac-Mo₁₋ₓVₓS₂. By optimizing the thickness of solid precursors and the SiO₂-capping layer as well as the growth temperature, we demonstrate control over film thickness, vanadium concentration, and film uniformity. The presence of V−Svac pairs manifests in enhanced Svac concentration and charge density transfer among V−S−Mo atoms, with multifaceted benefits including increasing light absorption, photoluminescence quenching, crystal structure distortion, efficient binding of CO₂ or H₂O on the surface, improved charge transfer/transport, and a suitable energy band diagram. The 2D Svac-Mo₁₋ₓVₓS₂ model catalyst films exhibit stable and boosted photocatalytic CO₂ reduction to CO, specifically yielding approximately 5 times more than that of pristine MoS₂.
📄 中文摘要
本研究報告一種 SiO₂ 封蓋式氣-液-固(VLS)成長法,可將釩摻入二硫化鉬(MoS₂)超薄膜中並同時引入硫空位,形成 Svac-Mo₁₋ₓVₓS₂。透過優化固態前驅體厚度、SiO₂ 封蓋層厚度及成長溫度,成功控制了薄膜厚度、釩濃度與膜的均勻性。此 V−Svac 配對的存在帶來了多重效益:增強的硫空位濃度、V−S−Mo 原子間的電荷密度轉移、提升光吸收、螢光猝滅、晶格結構畸變、表面與 CO₂/H₂O 的高效鍵結、改進的電荷轉移/傳輸,以及合適的能帶圖。最終 2D Svac-Mo₁₋ₓVₓS₂ 模型觸媒薄膜展現了穩定且提升的光觸媒 CO₂ 還原為 CO 的活性,產率約為原始 MoS₂ 的 5 倍。
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