Oil spills and the emission of oily wastewater have triggered serious water pollution and environment problems. Effectively separating oil and water is a world-wide challenge and extensive efforts have been made to solve this issue. Interfacial super-wetting separation materials e.g., sponge, foams, and aerogels with high porosity tunable pore structures, are regarded as effective media to selectively remove oil and water. This review article reports the latest progress of polymeric three dimensional porous materials (3D-PMs) with super wettability to separate oil/water mixtures. The theories on developing super-wetting porous surfaces and the effects of wettability on oil/water separation have been discussed. The typical 3D porous structures (e.g., sponge, foam, and aerogel), commonly used polymers, and the most reported techniques involved in developing desired porous networks have been reviewed. The performances of 3D-PMs such as oil/water separation efficiency, elasticity, and mechanical stability are discussed. Additionally, the current challenges in the fabrication and long-term operation of super-wetting 3D-PMs in oil/water separation have also been introduced.

It is not unusual for humans to be inspired by natural phenomena to develop new advanced materials; such materials are called bio-inspired materials. Interest in bio-inspired polymeric superhydrophilic, superhydrophobic, and superoleophobic materials has substantially increased over the last few decades, as has improvement in the related technologies. This review reports the latest developments in bio-inspired polymeric structures with desired wettability that have occurred by mimicking the structures of lotus leaf, rose petals, and the wings and shells of various creatures. The intrinsic role of surface chemistry and structure on delivering superhydrophilicity, superhydrophobicity, and superoleophobicity has been extensively explored. Typical polymers, commonly used structures, and techniques involved in developing bio-inspired surfaces with desired wettability are discussed. Additionally, the latest applications of bio-inspired structures with desired wettability in human activities are also introduced.

In this work, C-doped TiO₂ nanorods were synthesized through doping carbon black into hydrothermally synthesized solid-state TiO₂ nanowires (NWs) via calcination. The effects of carbon content on the morphology, phase structure, crystal structure, and photocatalytic property under both UV and solar light by the degradation of methylene blue (MB) were explored. Besides, the photoelectrochemical property of C-TiO₂ was systematically studied to illustrate the solar light degradation mechanism. After doping with C, TiO₂ NWs were reduced into nanorods and the surface became rough with dispersed particles. Results showed that C has successfully entered the TiO₂ lattice, resulting in the lattice distortion, reduction of band gap, and the formation of C–Ti–O, which expands TiO₂ to solar light activation. Comparing with P25 and anatase TiO₂ NWs, doping with carbon black showed much higher UV light and solar light photocatalytic activity. The photocatalytic activity was characterized via the degradation of MB, showing that K_ap was 0.0328 min^–1 under solar light, while 0.1634 min^–1 under UV irradiation. The main free radicals involved in methylene blue degradation are H⁺ and OH^•–. Doping with carbon black led to the reduction of photocurrent in a long-term operation, while C-doping reduced the electron–hole recombination and enhanced the carrier migration.