NiO/In_2O_3 p-n结型光催化剂的制备及其降解盐酸强力霉素研究

Preparation of p-n heterojunction-like NiO/In_2O_3 photocatalysts and their degradation performance of doxycycline hyclate

采用水热合成法制备出了具有p-n异质结结构的立方形氧化铟表面负载片状氧化镍复合光催化剂。SEM,XRD和UV-VIS,FT-IR等方法对催化剂的晶相组成、微观结构、化学键组成以及吸光性能等进行了表征。结果表明,NiO/In_2O_3复合光催化剂的形成符合牺牲模板机理。片状氧化镍的负载使复合光催化剂的吸收带边发生了明显的红移,并在可见光区产生响应。光催化降解盐酸强力霉素实验表明,与单一的In_2O_3相比,氧化镍颗粒的负载使二氧化铟的光催化效果在紫外-可见光区有了明显地提高,且在中性以及碱性条件下的光催化效果最佳,降解效率达到93%,其主要原因应归功于氧化镍晶粒与二氧化铟晶粒紧密接触形成p-n异质结,有助于催化剂表面光生电子和空穴的快速分离。

NiO nanosheets were successfully loaded on the surface of cubic In_2O_3 through the hydrothermal method to form NiO / In_2O_3 composite photocatalysts with p-n heterojunction structure. The phase composition,particle morphology,microstructures,chemical bonds and light response of the p-n junction-like NiO / In_2O_3 photocatalysts were characterized by scanning electron microscope（ SEM）,X-ray powder diffraction（ XRD）,ultraviolet-visible spectrophotometry（ UV-VIS） and Fourier transform infrared spectroscopy（ FT-IR）,respectively. The results showed that the formation of NiO / In_2O_3 composite photocatalysts conformed to the sacrificial template mechanism.The optical response of the photocatalysts showed a clear red-shift and moved to the visible-light area due to the loading of NiO nanosheets. The photo-catalytic activity of NiO / In_2O_3 photocatalysts was then tested by the degradation of doxycycline under ultraviolet-visible light irradiation. The decomposition efficiency of doxycycline was significantly enhanced due to the doping of NiO particles onto the surface of In_2O_3 matrix and the best degradation efficiency of doxycycline of 93% should be achieved under the conditions of neutral and alkaline aqueous solutions. The aggrandizement of degradation efficiency reason should be attributed to the unique p-n junction structure between NiO grain and In_2O_3 matrix,which was helpful to the separation of photo-generated electrons and holes on the surface of photocatalysts.