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The photoactive materials broadly applied in catalysis and energy conversion are generally composed of metal oxides. Among these oxides, ZnO showed a promising photocatalytic activity; however, traditional synthetic routes generated by-products and large amounts of secondary waste. Herein, we report the use of bipolar electrochemistry to generate ZnO nanoparticles using deionized water and a zinc metal to conform to green chemistry practices. TEM imaging demonstrated that the sizes of the bipolar-made ZnO particles were smaller than the commercial sample. The presence of structural defects in ZnO was correlated with the chemical shifts analyzed by X-ray photoelectron spectroscopy (XPS) and by different concentrations of O2− ions in stoichiometric and defected lattice. Further, the diffuse reflectance UV–Vis studies demonstrated a blue-shift in the reflectance spectrum for the bipolar-made oxide. This was also an indication of defects in the ZnO lattice, which related to the formation of shallow levels in the bandgap of the material. The structural and morphological differences influenced the photocatalytic characteristics, revealing a higher photocurrent for the bipolar-made ZnO when compared to the reference sample. This was further manifested in lower total resistivity for all anodes made from the non-stoichiometric ZnO, and also in their shorter diffusion length for charge exchange and electron lifetimes.

In the sports product industry, technical apparel materials can be developed to be perceived warm or cool to the human touch. Those created for warm touch are typically for cold environments - generating warmth for athlete comfort, whereas cool touch materials are developed for hot environments – making the athlete’s skin surface feel cool and fresh. These attributes can be engineered into the face or back side of the material – providing different point-of-purchase and next-to-skin perceptual experiences. The goal of this study was to define warm and cool touch effusivity spectrums that the sports apparel industry can reference when developing new technical materials. The warm and cool touch characteristics of common sports materials were evaluated mechanically with a Modified Transient Plane Source (MTPS) sensor and perceptually with a human subject fingertip test protocol. From the data collected, cool and warm touch effusivity spectrums were determined for face and back material sides. For the face side of the material specimens, subjects’ perception of warmth was at an average effusivity value of 145.9 (+/-23.1), and cool at 182.2 (+/-19.7). For the back side of the specimens, the materials were perceived warm at 138.6 (+/-22.6), and cool at 177.3 (+/-19.3). The results of this study provide sports apparel material developers insight into target effusivity value ranges for athlete warm or cool touch perceptual experiences.

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