No abstract

A facile route was adopted to synthesize heterostructured WO3/TiO2 photocatalysts from wood fibers through a two-steps hydrothermal method and a calcination process. The prepared WO3/TiO2-wood fibers were used as photocatalysts under UV irradiation for photodegradation of rhodamine B, methylene blue and methyl orange. In calcination process, the wood fibers acted as carbon substrates to prepare the WO3/TiO2 photocatalysts with high surface area and unique morphology. Thus, the significant enhanced photodegradation efficiency of the organic pollutants with the WO3/TiO2-wood fibers under UV irradiation was obtained. The photodegradation rates are measured which confirms the highest performance of the WO3/TiO2-wood fibers after calcination in comparison to the TiO2-wood fibers after calcination and the pure WO3/TiO2 after calcination. Moreover, the photodegradation efficiency of the WO3/TiO2-wood fibers after calcination under visible light is high. Our results demonstrated that the WO3/TiO2-wood fibers after calcination are a promising candidate for wastewater treatment in practical application.

No abstract

Inspired by the distinct functions of desert beetles with efficient droplet nucleation and lotus leaves with excellent droplet removal, an integrated method is presented for the design of a superhydrophobic surface decorated with hydrophilic groups that can efficiently nucleate and remove water droplets. We constructed a cellulose-based superhydrophobic surface containing numerous olefin terminal groups by solvent exchange and spray coating. This surface is different from most of the reported biomimicking water harvesting surfaces that rely on complicated lithography and micropatterning techniques requiring special instruments. The obtained superhydrophobic surface was further modified using various thiol compounds via a thiol–ene reaction to manipulate the water harvesting property. The modified surfaces containing hydrophobic groups (e.g., 1-octadecanethiol and 1H,1H,2H,2H-perfluorodecanethiol) or a strong hydrophilic group (e.g., 3-mercaptopropionic acid and 6-mercapto-1-hexanol) exhibited insufficient fog collecting abilities due to poor water droplet nucleation or strong water adhesion. By contrast, the modified surface decorated with moderately hydrophilic amino groups combines the advantages of biological surfaces with distinct wetting features (such as fog-harvesting beetles and water-repellent lotus leaves), resulting in accelerated water nucleation and less compromise of the water removal efficiency. Molecular dynamic simulations revealed that the efficient droplet nucleation is attributed to the hydrophilic amino groups whereas the rapid droplet removal is due to the maintained superhydrophobicity of the amino group-modified surface. This strategy of decorating a superhydrophobic surface with moderately hydrophilic functional groups provides insight into the manipulation of droplet nucleation and removal for water collection efficiency.

No abstract

No abstract

How to protect the sensitivity of gas sensing system in the case of persistent leakage in a closed environment? The aim of this study is to combine the gas sensing property of semiconductor with its photocatalytic performance, which may be viable alternative to give recovery time to gas sensors in the closed environment. By using Papilioparis butterfly wings as biotemplates, we herein demonstrate a facile way to synthesize biomass carbon doped TiO 2 with the replication of quasi-honeycomb scales structures, which is beneficial to highest specific area (85.27 m 2 •g −1 ) in comparison with pure TiO 2 and Ag-doped TiO 2 . The biomorphic C/TiO 2 exhibit not only excellent responses to benzene and dimethylbenzene vapors at 300 °C operating temperature superior to that of Ag-doped TiO 2 , but also have excellent sensitivity to visible light. Furthermore, the multifunctional biomorphic C/TiO 2 , used as safe concentration detectors, could determine vapors concentrations by gas sensing response values. Adopting illuminating the photocatalysts in the closed environment, the responses to dimethylbenzene and benzene have almost no changes along with continuous vapors injection. This work shows a good example for exploring the integrated application of semiconductor materials and improving the gas sensors lifetime.

According to statistics, early in the 20th century, the proportion of positive and negative air ions on the earth is 1 : 1.2. However, after more than one century, the equilibrium state of the proportion had an obvious change, which the proportion of positive and negative air ions became 1.2 : 1, leading to a surrounding of positive air ions in human living environment. Therefore, it is urgent to adopt effective methods to improve the proportion of negative oxygen ions, which are known as “air vitamin”. In this study, negative oxygen ions production by the TiO2/Cu2O-treated wood under UV irradiation was first reported. Anatase TiO2 particles with Cu2O particles were doped on wooden substrates through a two-step method and further modification is employed to create remarkable superamphiphobic surface. The effect of Cu2O particles dopant on the negative oxygen ions production of the TiO2-treated wood was investigated. The results showed that the production of negative oxygen ions was drastically improved by doping with Cu2O particles under UV irradiation. The wood modified with TiO2/Cu2O composite film after hydrophobization is imparted with superamphiphobicity, antibacterial actions against Escherichia coli, and negative oxygen ions production under UV irradiation.