中文摘要：

采用固相法合成AgNbO_3/石墨烯复合纳米材料,利用透射电子显微镜（TEM）及紫外-可见漫反射光谱（UV-Vis）对样品的形貌及光学性质进行了表征。研究发现,AgNbO_3与石墨烯复合后,带隙能明显降低,吸收光波长范围增大。以甲基橙溶液的降解为光催化模型反应评价了AgNbO_3/石墨烯复合纳米材料的可见光催化性能。结果表明：与纯AgNbO_3相比,AgNbO_3/石墨烯复合纳米材料对甲基橙的可见光催化性能明显增强。实验条件下,经300℃煅烧的AgNbO_3/石墨烯（2∶1）复合纳米材料表现出最优的催化性能,它对甲基橙的可见光催化脱色速率系数约为纯AgNbO_3的10倍。光催化降解机理研究表明,促使甲基橙降解脱色的主要活性物种为·O_2~-和h＋。

英文摘要：

AgNbO3/graphene nanocomposites were synthesized via the technique of solid-solid grinding and subsequent sintering process. Surface structures and optical properties of the prepared materials were characterized by transmission electron microscopy and UV-Vis diffuse reflection spectroscopy. The results indicate that band-gap of AgNbO3 is lowered upon eompositing with graphene nanoparticles, thereby giving an absorption in a large range of wavelengths. Degradation of methyl orange （MO） is carried out to evaluate the photocatalytic activity of AgNbO3/graphene nanocomposites under visible light irradiation. Compared with pure AgNbO3 , AgNbO3/graphene composites exhibit significantly enhanced photocatalytie activity for MO. Moreover, AgNbO3/graphene （2：1 ） obtained at 300 ℃ exhibits the highest degradation degree of MO after an irradiation of 120 min with apparent kapp of 0. 034 min-1, which is about 10 times than that of the pure AgNbO3. The tests of radical scavengers confirm that O2- and h＋ are the main reactive species for the degradation of MO.