Kiriarachchi Hiran D, Abouzeid Khaled M, Bo Longli, El-Shall M Samy
Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284-2006, United States.
ACS Omega. 2019 Aug 14;4(9):14013-14020. doi: 10.1021/acsomega.9b01772. eCollection 2019 Aug 27.
This work reports the development of a fast and simple route for the synthesis of ZnO sea urchin (SU) nanostructures by the formation and assembly of ZnO nanorods under favorable growth conditions in an aqueous solution. The thermal treatment of a basic zinc acetate solution in ethanol results in the formation of aggregated seed clusters consisting of small ZnO nanorods, which were then grown in a precursor solution containing Zn(NO)·6HO and hexamethylenetetramine to assemble the SU structures from the anisotropic ZnO nanorods on the surface of the seed clusters. Each ZnO nanoparticle in the aggregated seed clusters grew sequentially into a ZnO nanorod, and the nanorods were concentric to the core of the clusters yielding the unique SU-like shape. In the presence of a capping agent such as cetyl trimethyl ammonium bromide (CTAB), the aggregated seed clusters were not formed, and the growth of the CTAB-capped ZnO nanorods resulted in separated rods with average aspect ratios of ∼10. The SU ZnO nanostructures exhibit a hexagonal wurtzite crystal structure and higher specific surface area (26.9 m/g) than the CTAB-capped nanorods (17.7 m/g). The SU ZnO nanostructures show superior photocatalytic efficiency for the degradation of three common organic dyes compared to the ZnO nanorods. The removal efficiencies of indigo carmine, methylene blue, and rhodamine B by the SU nanostructures were 99, 86, and 96%, respectively, after 1 h of UV irradiation. Therefore, the ZnO SU structures have the potential to be a versatile photocatalyst for the photodegradation of organic dyes in industrial wastewater.
本工作报道了一种快速简便的合成ZnO海胆（SU）纳米结构的方法，该方法通过在水溶液中有利的生长条件下ZnO纳米棒的形成和组装来实现。乙醇中碱性醋酸锌溶液的热处理导致形成由小ZnO纳米棒组成的聚集种子簇，然后在含有Zn(NO)·6HO和六亚甲基四胺的前驱体溶液中生长，以从种子簇表面的各向异性ZnO纳米棒组装SU结构。聚集种子簇中的每个ZnO纳米颗粒依次生长成ZnO纳米棒，并且纳米棒与簇的核心同心，产生独特的类SU形状。在存在诸如十六烷基三甲基溴化铵（CTAB）的封端剂的情况下，不会形成聚集种子簇，并且CTAB封端的ZnO纳米棒的生长导致平均纵横比约为10的分离棒。SU ZnO纳米结构呈现六方纤锌矿晶体结构，并且比表面积（26.9 m/g）高于CTAB封端的纳米棒（17.7 m/g）。与ZnO纳米棒相比，SU ZnO纳米结构对三种常见有机染料的降解表现出优异的光催化效率。在紫外光照射1小时后，SU纳米结构对靛蓝胭脂红、亚甲基蓝和罗丹明B的去除效率分别为99%、86%和96%。因此，ZnO SU结构有潜力成为工业废水中有机染料光降解的通用光催化剂。
