High piezo-photocatalytic efficiency of degrading organic pollutants has been realized from CuS/ZnO nanowires using both solar and mechanical energy. CuS/ZnO heterostructured nanowire arrays are compactly/vertically aligned on stainless steel mesh by a simple two-step wet-chemical method. The mesh-supported nanocomposites can facilitate an efficient light harvesting due to the large surface area and can also be easily removed from the treated solution. Under both solar and ultrasonic irradiation, CuS/ZnO nanowires can rapidly degrade methylene blue (MB) in aqueous solution, and the recyclability is investigated. In this process, the ultrasonic assistance can greatly enhance the photocatalytic activity. Such a performance can be attributed to the coupling of the built-in electric field of heterostructures and the piezoelectric field of ZnO nanowires. The built-in electric field of the heterostructure can effectively separate the photogenerated electrons/holes and facilitate the carrier transportation. The CuS component can improve the visible light utilization. The piezoelectric field created by ZnO nanowires can further separate the photogenerated electrons/holes through driving them to migrate along opposite directions. The present results demonstrate a new water-pollution solution in green technologies for the environmental remediation at the industrial level.

No abstract

No abstract

TiO2/ZnO nanowire arrays on stainless steel mesh for piezo-photocatalytic H2 production are synthesized via a two-step hydrothermal route. The photocatalytic H2 production efficiency under solar illumination can be enhanced by introducing mechanical vibration energy. As coutilizing the solar and mechanical energy (ultrasonic irradiation), the nanowires show high H2 production. The nanowire arrays also show excellent recyclability and stability. Additionally, this mesh-based structure can be retrieved easily from aqueous solution, which can meet the practical application demand. The working mechanism can be attributed to the piezo-photocatalytic effect, in which the piezoelectric field of bent ZnO nanowires and the built-in electric field of TiO2/ZnO heterostructures can efficiently separate the photogenerated electrons and holes for effectively producing H2. Present results provide a new strategy for developing photocatalytic H2 production techniques.

A new flexible smelling electronic skin (e‐skin) has been realized from PANI(polyaniline)/PTFE(polytetrafluoroethylene)/PANI sandwich nano­structures basing on the triboelectrification/gas‐sensing coupling effect. The e‐skin can be driven by human motion/breath and efficiently convert mechanical vibration into electric impulse. And the output current/voltage is significantly dependent on the environmental atmosphere (volatile organic compounds in air), which can act as olfactory bionic electric impulse. Taking ethanol gas as an example, the detection limit of the e‐skin at room temperature is 30 ppm, and the response is up to 66.8 upon exposure to 210 ppm ethanol. Interestingly, the response of the e‐skin keeps stable with different dimensional sizes or under different strains/bending status. The working mechanism can be ascribed to the coupling of triboelectrification effect and surface reaction at the interfaces. Furthermore, an application of the flexible smelling e‐skin for visually identifying drunken driver without any external electricity power has been demonstrated. The results can open a possible new direction for the development of specialized‐function e‐skin and will further expand the scope for self‐powered nanosystems.

No abstract

No abstract

No abstract