Jiakai Li,Changpeng Lv,Jiajia Song,Xiaoling Zhang,Xizhen Huang,Yingzhuo Ma,Haijie Cao,Na Liu
Superwetting materials have drawn unprecedented attention in the treatment of oily wastewater due to their preferable anti-fouling property and selective oil/water separation. However, it is still a challenge to fabricate multifunctional and environmentally friendly materials, which can be stably applied to purify the actual complicated wastewater. Here, a Ag/α-Fe 2 O 3 heterostructure anchored copper mesh was intentionally synthesized using a facile two-step hydrothermal method. The resultant mesh with superhydrophilicity and underwater superoleophobicity was capable of separating various oil/water mixtures with superior separation efficiency and high permeation flux driven by gravity. Benefiting from the joint effects of the smaller band gap of Ag/α-Fe 2 O 3 heterojunction, inherent antibacterial capacity of α-Fe 2 O 3 and Ag nanoparticles, favorable conductive substrate, as well as the hierarchical structure with superwettability, such mesh presented remarkably enhanced degradation capability toward organic dyes under visible light irradiation and antibacterial activity against both Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ) compared with the pure α-Fe 2 O 3 coated mesh. Impressively, the mesh exhibited bifunctional water purification performance, in which organic dyes were eliminated simultaneously from water during oil/water separation in one filtration process. More importantly, this mesh behaved exceptional chemical resistance, mechanical stability and long-term reusability. Therefore, this material with multifunctional integration may hold promising potential for steady water purification in practice.
Composite photocatalysts that consist of semiconductor and noble metal nanostructures have been considered to be the promising and crucial materials for straightforward improving the efficiency in photocatalytic process and for the conversion of solar to chemical energy. In this work, we fabricated Ag-α-Fe 2 O 3 hybrid composites through a self-catalytic growth method by using the aldehyde-modified spindle α-Fe 2 O 3 nanoparticles (NPs) as supports. The size of supported Ag NPs can be directly controlled on the surface of α-Fe 2 O 3 . The morphology and structure of the resulting Ag-α-Fe 2 O 3 hybrid composites were studied by various techniques, including SEM, TEM, and XRD. The distinct photocatalytic behaviors were examined through the photodegradation of RhB dye. It was found that with the Ag NPs, the photocatalytic activities were enhanced greatly and the size of the Ag NPs played a crucial influence on the photocatalytic behaviors of the Ag-α-Fe 2 O 3 composites.
Conventionally, the surface-enhanced Raman spectroscopy (SERS) measurement is performed by dispersing noble metal nanoparticles onto the target sample directly or assembling noble metal nanoparticles onto a micro-sized substrate. Despite it is flourishing, this method is not adequate for various samples, mainly limited by either a defined confinement of the test position or the complex extraction process of the target sample on the irregularly shaped surface, besides the costive materials, complex and uncontrollable fabricating processes. Herein, we demonstrate that the α-Fe 2 O 3 thin film is decorated with Ag nanoparticles constructed on SiO 2 fibers as a flexible SERS-active substrate, which yields a functional optical enhancement of the signal at 532 nm laser excitation . It shows a high enhancement factor of 4.71 × 10 5 , ultrahigh sensitivity of 10 −15 M, and excellent signal stability with a relative standard deviation (RSD) of 1.22% and reproducibility with a RSD of 0.258%.