Ag-NaTaO_3-RGO复合物的合成及其改进的光催化制氢性能（英文）

Ag-NaTaO_3-RGO Composite:Synthesis and Improved Photocatalytic Hydrogen Production Property

以石墨粉,钽酸钠以及硝酸银为原料,通过三步合成法制备出一系列Ag-NaTaO_3-RGO复合材料。并对样品在紫外光照射下的光解水制氢活性进行了评价。结果表明:系列Ag-NaTaO_3-RGO复合材料均表现出较高的光解水制氢活性。其中,性能最优的0.2Ag-NaTaO_3-RGO的制氢速率分别是NaTaO_3,Ag-NaTaO_3,和NaTaO_3-RGO的5.64,1.97和1.48倍。对Ag-NaTaO_3-RGO复合材料光催化制氢性能改进的原因进行了探讨:(1)石墨烯具有优异的电子转移性能,能够有效阻止光生电子、空穴的复合。(2)银纳米颗粒充当电子陷阱,能够进一步提高电子空穴分离速率。(3)石墨烯的引入增强了复合物的光吸收性能。最后,根据所得实验数据,给出了Ag-NaTaO_3-RGO复合材料光催化制氢的反应机理。

The fabrication and characterization of Ag-NaTaO3-reduced graphene oxide （RGO） composite as an effective photocatalyst are presented. The Ag-NaTaO3-RGO composites with enhanced photocatalytic efficiency were synthesized by a three-step method. The photocatalytic activity of the samples was evaluated by photocatalytic water splitting hydrogen-evolution under ultraviolet light irradiation. Compared with NaTaO3, Ag-NaTaO3, and NaTaO3-RGO, the as-prepared 0.2Ag-NaTaO3-RGO composite exhibits the highest H2 production rate which was around 5.64, 1.97 and 1.48 times higher than that of pure NaTaO3, Ag-NaTaO3 and NaTaO3-RGO. The enhancement of H2 production can be mainly attributed to the following three factors：（i） the efficient separation of electron-hole pairs originated from the excellent electron transfer property of graphene. （ii） the further improvement of electron-hole separation rate due to Ag nanoparticle acted as electron traps. （iii） the enhancement of light absorption over the entire range of wavelengths with the introduction of graphene. In addition, plausible mechanism for the enhanced photocatalytic hydrogen production over the Ag-NaTaO3-RGO composite was proposed. This work demonstrates that rational composite of two or more phases of semiconductor should be a good strategy to design efficient photocatalysts.