超声雾化辅助微波法合成氧化锌纳米颗粒及其光催化性能

氧化锌(ZnO)具有宽带隙、高光催化效率和稳定的化学性质,已成为处理水体中有机污染物的常用材料。采用超声雾化辅助微波法成功合成了ZnO纳米颗粒,XRD图谱和TEM照片表明超声雾化抑制了ZnO结晶,其结构为无序状,得到的ZnO纳米颗粒为非晶态。非晶态ZnO纳米颗粒紫外最强吸收峰为300 nm,紫外吸收边发生红移,禁带宽度降至3.17 eV,紫外吸收率高于晶态ZnO颗粒,光催化活性显著提高,对Rhodamine B催化降解效率较晶态ZnO颗粒高出37%。超声雾化辅助微波法是一种低温、低能耗合成非晶态ZnO纳米颗粒的方法,合成的ZnO纳米颗粒光催化活性高,但其光催化效率随催化循环次数增加而降低,其分散性和稳定性有待进一步改善。

Photocatalytic Performance of Zinc Oxide Nanoparticles Synthesized by Ultrasonic Atomization-Assisted Microwave Method

Zinc oxide(ZnO) is widely used as a photocatalyst in the treatment of organic pollutants in wastewater due to its wide bandgap, high photocatalytic efficiency, and stable chemical properties. Based on the results by X-ray diffraction and transmission electric microscopy, synthesized ZnO remains a highly disordered structure because the crystallization of ZnO is suppressed by ultrasonic atomization. Amorphous ZnO nanoparticles were synthesized by a ultrasonic atomization-assisted microwave sintering method. Amorphous ZnO nanoparticles with a highly disordered structure enhance the absorption at a wavelength of 300 nm. The UV absorption of amorphous ZnO nanoparticles shifts to the lower energy side and is greater than that of crystal ZnO nanoparticles. The forbidden bandwidth of amorphous ZnO nanoparticles reduces to 3.17 eV. The photocatalytic efficiency of amorphous Zn O nanoparticles is improved, and the photocatalytic degradation efficiency of amorphous ZnO nanoparticles on Rhodamine B(RB) is 37% greater than that of crystal ZnO nanoparticles. Ultrasonic atomization-assisted microwave sintering method could be an effective method for preparing amorphous Zn O nanoparticles at a low temperature and a low energy consumption. Amorphous Zn O nanoparticles are a highly efficient photocatalyst. However, since the photocatalytic efficiency of amorphous ZnO nanoparticles could decrease with increasing the catalytic cycles, the stability and dispersion of amorphous Zn O nanoparticles should be thus further improved.