One of the major challenges in the removal of organic pollutants is to design a material with high efficiency and high flux that can remove both cationic and anionic dyes, oil-in-water (O/W) emulsion and heavy metal ions. Herein, we constructed novel chemically stabilized MgAl-layered-double-hydroxide/sepiolite (MgAl-LDH/Sep) composite membranes via 3D hierarchical architecture construction methods. These membranes were analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD), etc. Benefiting from the presence of hydrophilic functional groups on the surface of the film, the membranes show an enhanced water flux (~1200 L·m−2 h−1), while keeping a high dyes rejection (above 99.8% for anionic and cationic dyes). Moreover, the CA membrane coupled with MgAl-LDH/Sep exhibits a multifunctional characteristic for the efficient removal of mesitylene (99.2%), petroleum ether (99.03%), decane (99.07%), kerosene (99.4%) and heavy metal ion in water due to the layer-by-layer sieving. This hierarchical architecture is proved to have excellent environmental and chemical stability. Therefore, the membrane has potential in the treatment of sewage wastewater.

Reduced graphene oxide/copper matrix composites (RGO/Cu) are successfully fabricated via powder metallurgy methods. Composite powders of electrolytic Cu and 0.5 or 1.0 wt% graphene oxide (GO) are prepared by high‐energy ball milling. The composites are then consolidated using hot‐press sintering with a pressure of 22 MPa at 800 °C under a vacuum of 2 × 10−2 Pa. Microstructural observations of the RGO formed from GO show that it is located along the Cu grain boundaries and CuO nanoparticles distributed inside the Cu grain. The average grain sizes are 30.11 (pure Cu), 24.75 (0.5 wt% RGO/Cu composites), and 19.66 µm (1.0 wt% RGO/Cu composites). The Vickers hardness and tensile strengths of the RGO/Cu composites are higher than those of pure Cu. Theoretical research based on first‐principles calculations shows that oxygen atoms from the decomposition of GO react with Cu to form CuO nanoparticles. This secondary phase behaves as a pin that hinders the growth of copper grains. The covalent bonding between RGO and Cu slightly limits the movement of neighboring Cu atoms. More importantly, the grain refinement mechanism is related to the RGO retarding the diffusion of Cu atoms along the interface of copper grains due to its large activation energy.