复合光催化膜MoS2/Ag/TiO2同步降解有机物及产氢的研究

Simultaneously hydrogen production organic degradation of MoS2/Ag/TiO2 in two chamber photo reactor

  • 摘要: 以玻璃纤维膜为基底制备了具有三元结构的新型MoS2/Ag/TiO2光催化膜. 该复合催化剂膜具有多层结构,能够在模拟太阳光和紫外光下进行产氢反应. 该光催化膜可以用于新型的双室光催化反应器中进行同步产氢与有机物降解. 在光催化过程中,氢气在反应器的阴极室产生,而有机物在阳极室进行降解. 当Ag负载量为1wt%, TiO2负载量为160wt%时,MoS2/Ag/TiO2复合催化膜的比产氢速率达到了最大值,在模拟太阳光下为产氢速率为85 mmol·h-1·m-2(产二氧化碳速率为88 mmol·h-1·m-2),能量转化较率最高可达0.85%,是纯TiO2 的2.3倍;在紫外光下产氢速率为68 mmol·h-1·m-2,是纯TiO2的1.2倍. 在光照下TiO2 和 MoS2同时受光的激发产生光生电子与空穴,由于Ag功函数比TiO2 的功函数低,电子从TiO2导带上转移至Ag再转移到MoS2价带上形成TiO2→Ag→MoS2 的电子传递模式.因此,能更有效的实现电子与空穴的分离,提高产氢的效率.

     

    Abstract: A novel and environmentally friendly photocatalyst film, MoS2/Ag/TiO2, was synthesised on a glass-fibre membrane. The composite catalyst film had a multi-layer structure and responded well to solar light. The catalyst performed well for both photocatalytic hydrogen production and organic degradation in a two-chamber photo-reactor under either solar or UV light irradiation. Hydrogen was produced in the cathode side chamber while the model organic was decomposed in the anode side chamber. The specific hydrogen production rate went through a maximum of 85 mmol·h-1·m-2 with an energy conversion efficiency of 0.85% and a quantum yield of 12% under solar light, while a maximum of 68 mmol·h-1·m-2. It is apparent that Ag functioned as a nanojunction between the TiO2 and MoS2 layers, which allowed the transfer of photo-excited electrons via TiO2→Ag→MoS2 for organic degradation and H+ reduction (hydrogen evolution) in two different chambers.

     

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