The high surface energy of TiO2 nanoparticulate leads to the aggregation of nanoparticles. The grafted modification of nanoparticles is necessary in order to improve its dispersibility in the organic solvent. The effect of grafted modification with silane coupling agent on dispersibility and lipophilicity of TiO2 nanoparticles was investigated. The factors of the modification were discussed, such as the amount of silane coupling agent, pH value, and reaction time. The average sizes of the TiO2 nanoparticles were 200–300 nm. The thermogravimetric analysis (TGA) curves indicated that the TiO2 nanoparticle surface had been grafted with the silane coupling agent. The zeta potential showed that modified TiO2 could disperse well in the organic solvent. The lipophilic degree and contact angle suggested that the modified TiO2 had low surface energy and changed from a hydrophilic nature to a lipophilic nature.

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The long-term shortage of freshwater resources has drawn increasing research attention for water purification and collection. This work reports a facile method to prepare Janus fabrics with asymmetric wettability for on-demand oil/water separation and hydrophobic/hydrophilic patterned fabrics for efficient fog harvesting. Here, the superhydrophobic fabric was prepared by in situ polymerization of polydivinylbenzene (PDVB) on cotton fabric. By regulating the polymerization time, the PDVB polymer content was changed, thereby achieving the regulation of the surface structure and wettability of the prepared fabric. Meanwhile, the superhydrophobic fabric exhibited excellent selfcleaning and antifouling performance, mechanical abrasion and chemical resistance, and environmental durability. Moreover, the photocatalytic degradation properties of PDVB were utilized to prepare the Janus fabric with asymmetric wettability. Water droplets could spontaneously penetrate from the hydrophobic side to the hydrophilic side, while not vice versa, achieving unidirectional transport of water. In addition, the prepared Janus fabric could be used for on-demand oil/water separation, including the heavy oil/water mixture and light oil/water mixture. The separation efficiency and collected oil purity of each mixture were higher than 99.00 and 99.94%, respectively. Furthermore, the hydrophobic/ hydrophilic patterned fabrics were prepared by using the lithographic masks with different apertures under UV light irradiation. Based on the fog-capturing ability of the hydrophilic areas and the water transport performance of the hydrophobic regions, efficient fog harvesting was achieved. For the patterned fabric with larger hydrophobic/hydrophilic areas, the water collection rate reached 224.7 mg cm −2 h −1 . Therefore, this simple strategy to achieve controllable gradient wettability by adjusting the surface structure and chemical composition of the fabric shows great potential in the filtration of purification of oily sewage and the efficient condensed collection of water.

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The increasing demand for clean water driven by the rapid growth of the population and the pollution of water necessitates the development of direct and rapid water harvesting methods. Fog harvesting is proven as a highly efficient water capture method in dry but foggy areas. Herein, the state-of-the-art developments on the multiple biomimetic fog harvesting devices (FHDs) are presented. First, the fundamental and specific mechanisms of fog harvesting involving the Namib Desert beetle, spider silk, cactus, and Nepenthes alata are described in detail, respectively. Second, an in-depth discussion on the mechanisms of fog harvesting including fog capture and water transport is proposed. Third, a detailed account of the innovative design strategies and fabrication technologies of FHDs is proposed, from single to multiple biomimetic FHDs with typical examples and the merits and demerits are compared. Finally, a critical analysis of current challenges and future development is presented, aiming to promote next-generation FHDs from scientific research to practical application.

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A self-healing zinc anode is achieved by introducing a liquid Ga–In–Zn alloy as a protective layer on zinc foil. The high fluidity and deformability of the liquid alloy ensure an ultralong cycling life by enabling dendrite-free Zn deposition.