Piezoelectric nanogenerators (PENG) with flexible and simple design have pronounced significance in fabricating sustainable devices for self-powering electronics. This study demonstrates the fabrication of electrospun nanocomposite fibers from polyvinylidene fluoride (PVDF) filled zinc oxide (ZnO)/iron oxide (FeO) nanomaterials. The nanocomposite fiber based flexible PENG shows piezoelectric output voltage of 5.9 V when 3 wt% of ZnO/FeO hybrid nanomaterial is introduced, which is 29.5 times higher than the neat PVDF. No apparent decline in output voltage is observed for almost 2000 s attributed to the outstanding durability. This higher piezoelectric output performance is correlated with the β-phase transformation studies from the Fourier transformation infrared spectroscopy and the crystallinity studies from the differential scanning calorimetry. Both these studies show respective enhancement of 3.79 and 2.16% in the β-phase crystallinity values of PVDF-ZnO/FeO 3 wt% composite. Higher dielectric constant value obtained for the same composite (three times higher than the neat PVDF) confirms the increased energy storage efficiency as well. Thus the proposed soft and flexible PENG is a promising mechanical energy harvester, and its good dielectric properties reveals the ability to use this material as good power sources for wearable and flexible electronic devices.

Current environmental restrictions, such as the zero liquid discharge policy, require developing new methods to completely remove micropollutants from wastewater. Non‐steroidal anti‐inflammatory drugs (NSAID) are major component of such pollutants. The adsorptive removal of ketoprofen (KP), a widely prescribed NSAID, was studied using a newly synthesized magnetic adsorbent. The maximum adsorption capacity was determined to be 39.2 mg/g with almost 98 % removal for 50 mg/L KP at neutral pH. The adsorption of KP was found to be pH dependent and more efficient in acidic media. The isothermal behavior of the adsorbent followed a sigmoidal behavior and was best fitted to the corresponding‐states equation (CSE). The adsorption was found to follow second‐order kinetics with a half‐life of 4.4 min. The adsorption was also found to be exothermic and therefore it is favorable at low temperatures. The study also showed that the adsorbent can be regenerated for several adsorption‐desorption cycles. The adsorption mechanism was also explored by state‐of‐the‐art periodic quantum theoretical calculations.

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Piezoelectric nanogenerators (PENG) with flexible and simple design have pronounced significance in fabricating sustainable devices for self-powering electronics. This study demonstrates the fabrication of electrospun nanocomposite fibers from polyvinylidene fluoride (PVDF) filled Zinc Oxide (ZnO)/Iron Oxide (FeO) nanomaterials. The nanocomposite fiber based flexible PENG showed piezoelectric output voltage of 5.9 V when 3 wt.% of ZnO/FeO hybrid nanomaterial was introduced, which was 29.5 times higher than the neat PVDF. No apparent decline in output voltage was observed for almost 2000 seconds attributed to the outstanding durability. This higher piezoelectric output performance is correlated with the β-phase transformation studies from the Fourier transformation infrared spectroscopy and the crystallinity studies from the differential scanning calorimetry. Both these studies show respective enhancement of 3.79 and 2.16 % in the β-phase crystallinity values of PVDF-ZnO/FeO 3 wt.% composite. Higher dielectric constant value obtained for the same composite (3 times higher than the neat PVDF) confirms the increased energy storage efficiency as well. Thus the proposed soft and flexible PENG is a promising mechanical energy harvester, and its good dielectric properties reveals the ability to use this material as good power sources for wearable and flexible electronic devices.

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