水热法制备球花状MoS2及其热红联用分析

Hydrothermal Preparation of Petal-like MoS2 and its TG-DSC-FTIR Analysis

摘要:

以Na₂MoO₄为钼源,CS(NH₂)₂为硫源,H₂C₂O₄为还原剂,采用水热合成法制备了球花状MoS₂微球,并利用XRD、SEM-EDS和TG-DSC-FTIR等分析手段对其晶型、微观形貌、热性能等进行分析。研究结果表明：Mo/S比、还原剂添加量、反应温度和反应时间均对产物收率产生影响。球花状微球为纯净的六角2H-MoS₂,微球直径约为1-2 um,微球上球花厚度约为15-20 nm。球花状MoS₂微球热损失大致可以分为两个阶段：MoS₂转化阶段(温度区间为221.40 °С～603.15 °С)和MoO₃相变阶段(温度区间为603.15 °С～1220 °С)。转化阶段MoS₂转化为MoO₂和MoO₃,质量损失为22.3%；相变阶段主要是发生了固相MoO₃转变为液相和气相的相变反应。FTIR结果表明,SO₂气体在603.15℃之前全部析出,证明了MoS₂在600℃左右完全转化。与常规MoS₂相比,球花状MoS₂微球表现出更高的活性。

Abstract:

Petal-like MoS₂ microspheres were synthesized via the hydrothermal reaction of Na₂MoO₄, CS(NH₂)₂, and H₂C₂O₄. The crystal form and micro morphology of MoS₂ were analyzed by XRD and SEM, and its thermogravimetric and gas precipitation properties were studied via TG–DSC–FTIR. Results indicated that product yield was influenced by the molar ratio of Mo/S, amount of reducing agent, reaction temperature, and reaction time. The crystal form of petal-like MoS₂ microspheres was hexagonal 2H-MoS₂, which petal-like microspheres diameter was about 1-2 μm with 15-20 nm average thickness of petal. The thermal loss process of MoS₂ could roughly be divided into two stages: transformation stage of MoS₂ and phase change stage of MoO₃, wherein, first stage mainly focused in 221.40 °С～603.15 °С, and second stage occurred in the temperature range of 603.15 °С～1220 °С. MoO₂ and MoO₃ were generated in the first stage which thermal loss decreased by 22.30%. A phase change of MoO₃ from solid to liquid and gas appeared in the second stage. FTIR data showed that there was no SO₂ gas at 603.15 °С, which proved MoS₂ completely transformation before 600 °С. Compared with common MoS₂, the petal-like MoS₂ microsphere acted out high reaction activity.