碳量子点/硅酸铋纳米片复合光催化剂的构建及其光催化性能增强

Fabrication of carbon quantum dots/Bi_2SiO_5 nanosheets and enhancement of photocatalytic activity

通过一步法控制合成了碳量子点(CQDs)修饰的硅酸铋(Bi_2SiO_5)纳米片光催化剂。将平均直径6~8nm的CQDs分散在Bi_2SiO_5纳米片的表面。片状结构可加速载流子在Bi_2SiO_5纳米片内部之间的转移,通过CQDs表面修饰可以促进表面电荷分离。将CQDs引入Bi_2SiO_5纳米片后,在模拟太阳光照射下,可提高催化剂对罗丹明B的降解速率。这是由于CQDs的引入可以促进羟基自由基和超氧自由基的产生,从而提高了光催化性能。当CQDs的复合量为2%时,CQDs/Bi_2SiO_5纳米片的光催化活性最高,在模拟太阳光下照射90min后对RhB的降解率达到96%。

Carbon quantum dots（CQDs）modified Bi2SiO5 nanosheets have been synthetized by a controlled one-pot method.CQDs with average diameter of about 6-8 nm were dispersed on the surface of Bi2SiO5 nanosheets.The structure of nanosheets was beneficial to accelerate the transfer of photogenerated carriers among the Bi2SiO5 interior,and the modification of CQDs can promote the separation of photogenerated carriers.After introducing CQDs into the Bi2SiO5 nanosheets,the photocatalytic activity for the degradation of RhB under simulated sunlight irradiation was greatly improved.The modification of CQDs could boost the generation of both hydroxyl radical and superoxide radical,subsequently increase the photocatalytic performance of Bi2SiO5 nanosheets.When the CQDs content in the CQDs/Bi2SiO5 composite is 2%,the degradation rate of RhB could reach to96% under simulated sunlight for 90 min.