Porous hollow Co ₃ O ₄ parallelepipeds derived from a novel Co-MOF exhibit enhanced electrochemical performance when used as an anode material for LIBs.

N⁺-bombarded multi-walled carbon nanotubes (N⁺-bombarded MWCNTs), with different nitrogen atomic percentages, were achieved by different N ion beam currents using ion beam-assisted deposition (IBAD) on MWCNTs synthesized by chemical vapor deposition (CVD). Characterizations of N⁺-bombarded MWCNTs were evaluated by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Raman spectroscopy, and contact angle. For comparison, the in vitro cytocompatibility of the N⁺-bombarded MWCNTs with different N atomic percentages was assessed by cellular adhesion investigation using human endothelial cells (EAHY926) and mouse fibroblast cells (L929), respectively. The results showed that the presence of nitrogen in MWCNTs accelerated cell growth and proliferation of cell culture. The higher nitrogen content of N⁺-bombarded MWCNTs, the better cytocompatibility. In addition, N⁺-bombarded MWCNTs with higher N atomic percentage displayed lower platelet adhesion rate. No hemolysis can be observed on the surfaces. These results proved that higher N atomic percentage led N⁺-bombarded MWCNTs to better hemocompatibility.

The poriferous reduced graphene oxide (rGO) with abundant oxygen-containing functional groups synthesized by a one-step hydrothermal method was successfully employed as a high performance cathode in lithium-ion batteries. The electrochemical results show that the rGO exhibits a remarkable lithium storage capacity (up to 270 mA h g⁻¹ after 100 cycles). Further analysis shows that the rGO can exhibit a significantly high rate capacity, good reversibility, and excellent cycling stability, which clearly reveals the potential use of the rGO as the cathode material to boost both energy and power densities of LIBs. Furthermore, by controlling the oxygenic functional groups of the rGO, it was demonstrated that the capacity of rGO increased with the increase of the number of oxygenic functional groups, which illustrates that the excellent electrochemical performance of rGO could be attributed to its specific poriferous structure and the oxygen-containing functional groups.