Porous Hybrid PVDF/BiFeO3 Smart Composite with Magnetic, Piezophotocatalytic, and Light-Emission Properties

Abstract

The creation of multi-stimuli-sensitive composite polymer–inorganic materials is a practical scientific task. The combination of photoactive magneto-piezoelectric nanomaterials and ferroelectric polymers offers new properties that can help solve environmental and energy problems. Using the doctor blade casting method with the thermally induced phase separation (TIPS) technique, we synthesized a hybrid polymer–inorganic nanocomposite porous membrane based on polyvinylidene fluoride (PVDF) and bismuth ferrite (BiFeO3/BFO). We studied the samples using transmission and scanning electron microscopy (TEM/SEM), infrared Fourier spectroscopy (FTIR), total transmission and diffuse reflection, fluorescence microscopy, photoluminescence (PL), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), vibrating-sample magnetometer (VSM), and piezopotential measurements. Our results demonstrate that the addition of BFO increases the proportion of the polar phase from 76.2% to 93.8% due to surface ion–dipole interaction. We also found that the sample exhibits laser-induced fluorescence, with maxima at 475 and 665 nm depending on the presence of nanoparticles in the polymer matrix. Furthermore, our piezo-photocatalytic experiments showed that under the combined actions of ultrasonic treatment and UV–visible light irradiation, the reaction rate increased by factors of 68, 13, 4.2, and 1.6 compared to sonolysis, photolysis, piezocatalysis, and photocatalysis, respectively. This behavior is explained by the piezoelectric potential and the narrowing of the band gap of the composite due to the mechanical stress caused by ultrasound.

1D/2D Electrospun Polyvinylidene Fluoride Nanofibers/Carbon Flakes Hybrid Nonmetal Polymeric Photo‐ and Piezocatalyst

“…The reaction rate for PVDF/C 0.5 is 2.7 times higher than that of PVDF/C 1.5 and 10.3 times higher than that of pure PVDF. The very low photocatalytic activity of PVDF (lower than photolysis) is attributed to the giant light scattering characteristics of PVDF fibers [43] and its low absorption coefficient [41] …”

“…The very low photocatalytic activity of PVDF (lower than photolysis) is attributed to the giant light scattering characteristics of PVDF fibers [43] and its low absorption coefficient. [41] The results of the piezocatalytic activity of the samples under ultrasonic irradiation in the dark are presented in Figure 7c. In the control experiment without catalyst (sonolysis), 52 % of the MB decomposed in 60 minutes.…”

“…According to the works, [41–42] the most appropriate method for quantitative analysis of phase distribution in PVDF‐based samples is Fourier transform infrared (FTIR) spectroscopy. FTIR spectra were obtained for all the samples investigated, and the data are presented in Figure 4.…”

“…Smaller particles distributed along the fibers can act as nucleating agents and accelerate the crystallization rate, thereby promoting the formation of a polar β-phase. [40] According to the works, [41][42] the most appropriate method for quantitative analysis of phase distribution in PVDF-based samples is Fourier transform infrared (FTIR) spectroscopy. FTIR spectra were obtained for all the samples investigated, and the data are presented in Figure 4.…”

Exploring RF Magnetron Sputtering Growth Composite Thin Film BiFeO3-Bi2Fe4O9 on C-Plane Al2O3 Substrate

“…where T s t (λ) and R s d (λ) are the transmission and reflection spectra of the samples; T gl (λ) and R gl (λ) are the reference signal spectra, measured with quartz plates; T 0 (λ) is the integrating sphere signal with covered input and open output ports; R 0 (λ) is the signal for a sphere with open optical ports. The calculation of the spectral dependence of the coefficients of optical absorption µ a and light scattering µ s was carried out using the inverse method of the Monte Carlo numerical simulation, developed and described in detail in the works [20][21][22].…”