复合催化剂NiS/g-C_3N_4的制备及光催化产氢性能

The Preparation and Photocatalytic Hydrogen Production of Composite Catalyst NiS/g-C_3N_4

利用原位离子交换法制得复合催化剂Ni S/g-C_3N_4(g-C_3N_4为石墨相氮化碳),采用X射线衍射、透射电镜、紫外-可见漫反射光谱和红外光谱对该催化剂的组成、形貌和光物理性能进行了表征.以廉价的有机染料如曙红Y(EY)、中性红(NR)为敏化剂,三乙醇胺(TEOA)为牺牲剂,构建了完全不含贵金属的光催化产氢体系,考察了NiS的量、敏化剂种类与浓度、牺牲剂的体积分数及体系pH值对产氢性能的影响.结果表明,Ni S的复合和敏化剂EY的引入可使得g-C_3N_4的产氢性能显著提高.结合g-C_3N_4和Ni S/g-C_3N_4的荧光光谱性能,初步推测了该体系的产氢机理.

A composite catalyst NiS/g-C3N4（ g-C3N4= graphitic carbon nitride） was prepared via in situ template-free ion-exchange method,and its composition,morphology and photophysical properties were characterized by X-ray diffraction,transmission electron microscope,UV-Vis diffuse reflection spectroscopy and infrared spectrum,and so on. Then a non-noble metal photocatalytic hydrogen evolution system was constructed by using cheap organic dye,such as eosin Y（ EY）,neutral red（ NR） as photosensitizer,triethanolamine（ TEOA） as sacrificial agent,and the H2-evolving conditions,such as the loading amount of NiS,the variety and concentration of photosensitizer,the volume fraction of sacrificial agent and the p H value of the system were optimized. The results showed that the loading of NiS on g-C3N4 and introducing of sensitizer EY could result in significant improvements on the H2-evolving activity. Moreover,the reaction mechanism of this photocatalytic hydrogen evolution system based on the fluorescence properties of pure g-C3N4 and NiS/g-C3N4 composite catalysts was speculated.