Orudzhev F F, Sobola D S, Ramazanov Sh M, Častková K, Selimov D A, Rabadanova A A, Shuaibov A O, Gulakhmedov R R, Abdurakhmanov M G, Giraev K M
Smart Materials Laboratory, Dagestan State University, St. M. Gadjieva 43-a, 367015 Makhachkala, Russia.
Central European Institute of Technology BUT, Purkyňova 656/123, 61200 Brno, Czech Republic.
Polymers (Basel). 2023 Jul 30;15(15):3252. doi: 10.3390/polym15153252.
In this study, polyvinylidene fluoride (PVDF) fibers doped with hydrated calcium nitrate were prepared using electrospinning. The samples were analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), optical spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), Raman, and photoluminescence (PL) spectroscopy. The results are complementary and confirm the presence of chemical hydrogen bonding between the polymer and the dopant. Additionally, there was a significant increase in the proportion of the electroactive polar beta phase from 72 to 86%. It was shown that hydrogen bonds acted as a transport pathway for electron capture by the conjugated salt, leading to more than a three-fold quenching of photoluminescence. Furthermore, the optical bandgap of the composite material narrowed to the range of visible light energies. For the first time, it the addition of the salt reduced the energy of the PVDF exciton by a factor of 17.3, initiating photocatalytic activity. The calcium nitrate-doped PVDF exhibited high photocatalytic activity in the degradation of methylene blue (MB) under both UV and visible light (89 and 44%, respectively). The reaction rate increased by a factor of 2.4 under UV and 3.3 under visible light during piezophotocatalysis. The catalysis experiments proved the efficiency of the membrane design and mechanisms of catalysis are suggested. This study offers insight into the nature of chemical bonds in piezopolymer composites and potential opportunities for their use.
在本研究中，采用静电纺丝法制备了掺杂水合硝酸钙的聚偏氟乙烯（PVDF）纤维。使用扫描电子显微镜（SEM）、X射线衍射（XRD）、光谱学、X射线光电子能谱（XPS）、傅里叶变换红外（FTIR）、拉曼光谱和光致发光（PL）光谱对样品进行了分析。结果相互补充，证实了聚合物与掺杂剂之间存在化学氢键。此外，电活性极性β相的比例从72%显著增加到86%。结果表明，氢键作为共轭盐捕获电子的传输途径，导致光致发光淬灭超过三倍。此外，复合材料的光学带隙缩小到可见光能量范围。首次发现，盐的添加使PVDF激子的能量降低了17.3倍，引发了光催化活性。硝酸钙掺杂的PVDF在紫外光和可见光下对亚甲基蓝（MB）的降解均表现出高光催化活性（分别为89%和44%）。在压电光催化过程中，紫外光下反应速率提高了2.4倍，可见光下提高了3.3倍。催化实验证明了膜设计的有效性，并提出了催化机理。本研究深入了解了压电聚合物复合材料中化学键的性质及其潜在应用机会。
