Ag(Au)/石墨烯-TiO_2复合光催化剂的制备及其模拟太阳光光催化性能

Preparation of Ag(Au)/Graphene-TiO_2 Composite Photocatalysts and Their Catalytic Performance under Simulated Sunlight Irradiation

分别采用溶剂热还原和光还原沉积法制备了石墨烯-TiO2和Ag(Au)/石墨烯-TiO2复合光催化剂,并表征了其相结构、形貌、孔隙率、光谱吸收性质以及组成结构.结果表明,石墨烯与TiO2通过C-O-Ti共价键相互作用,Ag或Au纳米粒子均匀沉积在石墨烯和TiO2表面.在模拟太阳光照射下,通过对水相中罗丹明B和甲基橙的降解,考察了光催化剂活性的差异,并研究了其降解动力学.结果表明,由于量子效率的提高、带隙能的降低以及织构性质的优化,复合光催化剂表现出比纯TiO2更高的光催化活性.

To improve the solar utilization efficiency of TiO2, the graphene-TiO2 and Ag（Au）/graphene-TiO2 composite photocatalysts were prepared by solvothermal reduction and photoreduction deposition technique, respectively. The phase structure, morphology, porosity, optical absorption property as well as composition and structure of as-prepared materials were characterized. The results indicated that TiO2 interacts with graphene via Ti-O-C covalent bonds and Ag or Au nano-particles evenly deposite on the graphene and TiO2 surface. The photo-catalytic activity and degradation kinetics of the as-prepared photocatalysts were studied by the degradation of aqueous rhodamine B and methyl orange under solar simulating Xe lamp irradiation. The results indicated that the composite photocatalysts exhibit higher photocatalytic activity compared with pure TiO2 due to enhanced quantum efficiency, narrowed band gap, and perfect textural properties.