Arrabito Giuseppe, Delisi Antonio, Giuliano Giuliana, Prestopino Giuseppe, Medaglia Pier Gianni, Ferrara Vittorio, Arcidiacono Federica, Scopelliti Michelangelo, Chillura Martino Delia Francesca, Pignataro Bruno
Department of Physics and Chemistry-Emilio Segrè, University of Palermo, Viale delle Scienze 17, 90128 Palermo, Italy.
Department of Industrial Engineering, University of Rome "Tor Vergata", Via del Politecnico 1, 00133 Rome, Italy.
ACS Appl Eng Mater. 2023 May 3;1(5):1384-1396. doi: 10.1021/acsaenm.3c00082. eCollection 2023 May 26.
The design of multifunctional nanostructured materials is the key to the development of smart wearable devices. For instance, nanostructures endowed with both piezoelectric and photocatalytic activities could well be the workhorse for solar-light-driven self-cleaning wearable sensors. In this work, a simple strategy for the assembly of a flexible, semitransparent piezophotocatalytic system is demonstrated by leveraging rational wet chemistry synthesis of ZnO-based nanosheets/nanoflowers (NSs/NFs) under basic pH conditions onto flexible ITO/PET supports. A KMnO pretreatment before the ZnO synthesis (seeded ZnO) allows for the control of the density, size, and orientation of the NSs/NFs systems compared to the systems produced in the absence of seeding (seedless ZnO). The electrical response of the sensors is extracted at a 1 V bias as a function of bending in the interval between 0 and 90°, being the responsivity toward bending significantly enhanced by the KMnO treatment effect. The photocatalytic activity of the sensors is analyzed in aqueous solution (methylene blue, 25 μM) by a solar simulator, resulting in similar values between seedless and seeded ZnO. Upon bending the sensor, the photocatalytic activity of seedless ZnO is almost unaffected, whereas that of seeded ZnO is improved by about 25%. The sensor's reusability and repeatability are tested in up to three different cycles. These results open up the way toward the seamless integration of bending sensitivity and photocatalysis into a single device.
多功能纳米结构材料的设计是智能可穿戴设备发展的关键。例如，兼具压电和光催化活性的纳米结构有望成为太阳光驱动的自清洁可穿戴传感器的主力军。在这项工作中，通过在碱性pH条件下利用基于ZnO的纳米片/纳米花（NSs/NFs）的合理湿化学合成方法，将其组装到柔性ITO/PET载体上，展示了一种构建柔性、半透明压电光催化系统的简单策略。与无籽晶（无籽ZnO）条件下制备的系统相比，在ZnO合成之前进行KMnO预处理（籽晶ZnO）能够控制NSs/NFs系统的密度、尺寸和取向。在1 V偏压下提取传感器在0至90°弯曲区间内的电响应，KMnO处理显著增强了传感器对弯曲的响应度。通过太阳模拟器在水溶液（25 μM亚甲基蓝）中分析传感器的光催化活性，无籽和有籽ZnO的光催化活性值相近。弯曲传感器时，无籽ZnO的光催化活性几乎不受影响，而有籽ZnO的光催化活性提高了约25%。对传感器的可重复使用性和重复性进行了多达三个不同循环的测试。这些结果为将弯曲敏感性和光催化无缝集成到单个设备中开辟了道路。
