【摘要】 MoS₂是一种新的、低成本的析氢催化剂。在聚乙烯吡烙烷酮（PVP）存在下,以钼酸钠和硫代乙酰胺为原料,水热法合成了薄层MoS₂。该MoS₂在N,N-二甲基甲酰胺（DMF）溶剂中超声剥离后负载于P25 TiO₂上制备了薄层MoS₂/TiO₂。通过XRD、SEM、UV-Vis漫反射光谱、Zeta电势等手段表征该光催化剂。MoS₂负载增加了TiO₂的光吸收并降低其电荷零点p H。研究MoS₂制备与剥离条件对生物质甘油为电子给体的MoS₂/TiO₂光催化制氢活性的影响。结果表明,MoS₂在DMF剥离后的制氢活性比剥离前大大提高;MoS₂最佳负载量为1.60%（wt）,超声剥离MoS₂制备的MoS₂/TiO₂制氢活性是未剥离制备的4.18倍。DMF作为溶剂,超声分散效果明显比水好;PVP也促进了MoS₂的剥离,从而提高制氢活性。研究以甘油为电子给体的光催化制氢体系反应规律及机理。反应体系最佳pH与MoS₂/TiO₂的电荷零点pH一致;甘油浓度对制氢速率的影响符合Langmuir-Hinshelwood动力学模型,详细地讨论了反应机理。更多还原

【Abstract】 MoS₂ is a new and low-cost hydrogen evolution catalyst. Layered MoS₂ was synthesized by a hydrothermal method using sodium molybdate and thioacetamide as raw materials in the presence of polyvinyl pyrrolidone（PVP）. The layered MoS₂ was exfoliated via ultrasonication in dimethylformamide（DMF）, and then loaded onto P25 TiO₂ to obtain layered MoS₂/TiO₂ photocatalyst. The photocatalyst was characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, UV-Vis diffuse reflectance spectroscopy（DRS） and Zeta potential measurements. The results show that the loading of MoS₂ onto TiO₂ enhances photoabsorption of TiO₂ and decreases the p H of zero point of charge（p Hzpc）. Moreover, the effects of preparation and exfoliation conditions of MoS₂ on photocatalytic hydrogen production of MoS₂/TiO₂ using biomass glycerol electron donor were investigated. The results show that MoS₂ after exfoliation in DMF exhibits much higher hydrogen production activity than that of untreated. The optimal loading of MoS₂ is 1.60%（wt）, and the activity of MoS₂/TiO₂ prepared with exfoliated MoS₂ is 4.18 times higher than that prepared with un-exfoliated MoS₂. DMF as a solvent shows much better ultrasonic-dispersing ability than water, and PVP improves MoS₂ exfoliation and enhances its hydrogen production activity. The behavior and mechanism of the reaction system for photocatalytic hydrogen production using glycerol as an electron donor was studied. The results show that the optimal p H of the reaction system is consistent with the p Hzpc of MoS₂/TiO₂. The effect of glycerol concentration on hydrogen production rate follows the Langmuir–Hinshelwood kinetic model, and the reaction mechanism is discussed in detail.更多还原