A large quantity of nanosized ZnO tubular structures was prepared using a very simple thermal evaporation of mixed Zn–ZnO powders under a wet oxidation condition. The ZnO nanotubes have a hollow core with crystalline wall of 8–20 nm in thickness. Optical properties of ZnO nanotubes were studied at room temperature. Raman peaks arising from the ZnO nanotubes were analyzed, which correspond well to that of the bulk ZnO sample. The photoluminescence measurements of ZnO nanotubes revealed an intensive UV peak at 377 nm corresponding to the free exciton emission, and a broad peak at about 500 nm arising from defect-related emission.

Batteries constructed via 3D printing technique have inherent advantages including the opportunities for miniaturization, autonomous shaping, and controllable structural prototyping. However, 3D printed lithium metal batteries (LMBs) have not yet been reported due to the difficulties of printing lithium (Li) metal. Here, for the first time, we fabricated high-performance LMBs by a 3D printing technique using cellulose nanofiber (CNF), which is one of the most earth abundant biopolymers. The unique shear thinning property of the CNF gel enables the printing of the LiFePO 4 electrode and stable scaffold for Li. The printability of the CNF gel was also investigated theoretically. Moreover, the porous structure of CNF scaffold was also beneficial for improving ion-accessibility and decreasing the local current density of Li anode. Thus dendrite formation due to uneven Li plating/stripping was suppressed. Multi-scale computational approach integrating first-principle density function This article is protected by copyright. All rights reserved.2 theory (DFT) and phase-field model (PFM) was performed to reveal the porous structure have more uniform Li deposition. Consequently, full cell built with 3D printed Li anode and LiFePO 4 cathode exhibits a high capacity of 80 mA h g -1 at a charge/discharge rate of 10 C with capacity retention of 85% even after 3000 cycles.

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The preparation of superoleophobic and superhydrophobic surfaces requires surface microgeometries and surface chemistry. In this study, an economical and environmentally friendly electrochemical etching method was developed to prepare superoleophobic and superhydrophobic titanium surfaces. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectrophotometry (FTIR), energy-dispersive spectroscopy (EDS), and optical contact angle measurements were used to characterize the surface morphologies, crystal structures, chemical compositions, and wettability of the surfaces for both water and oil. The results show that the prepared superoleophobic surface has water, glycerol, and hexadecane contact angles above 150°, with rolling angles of only 1–2°. Analysis of the electrolyte, the reaction process, and the products demonstrates that the proposed method is inexpensive and environmentally friendly. The effects of electrochemical parameters such as current density, electrochemical etching time, electrolyte temperature, and electrolyte concentration on the surface wettability for water, glycerol, and hexadecane were also investigated. Superoleophobicity and superhydrophobicity can be selectively obtained by varying the electrochemical parameters. The proposed method is believed to be adopted for industrial production of superoleophobic and superhydrophobic titanium surfaces.