Bi₅Ti₃FeO₁₅ Nanofibers for Highly Efficient Piezocatalytic Degradation of Mixed Dyes and Antibiotics

Abstract

A piezocatalyst with highly efficient catalytic efficiency toward multiple pollutants’ removal can improve treatment efficiency and reduce the consumption of catalysts, which is ideal for practical applications. Herein, Bi5Ti3FeO15 nanofibers were prepared using electrospinning and its excellent piezocatalytic performances for mixed dyes’ and antibiotics’ degradation were revealed. Rhodamine B (RhB) is degraded by 98% in 20 min, and the acquired reaction rate constant is 0.195 min–1 under ultrasonic vibration. Particularly, the mixed dyes of RhB, acid orange 7, methylene blue, and methyl orange are simultaneously degraded within 40 min, a high rate constant of 0.106 min–1 is achieved, and the degradation efficiencies can be always maintained at ∼100% for five consecutive cycles. The obtained rate constant for mixed dyes’ degradation is superior to many of the previously reported catalysts just toward one dye degradation. Furthermore, it is further demonstrated that tetracycline hydrochloride, bisphenol A, and phenol can be also efficiently degraded by 94, 90, and 79%, respectively, within 30 min. The piezocatalytic performances of nanofibers at different pH values and reaction temperatures were also explored. Catalytic mechanism investigations demonstrate that the optimized Bi5Ti3FeO15 nanofibers possess a weaker carrier recombination rate, smaller carrier transfer resistance, and higher carrier separation efficiency, which account for its superior piezocatalytic performance. This work reveals that Bi5Ti3FeO15 nanofiber is a superior catalyst for organic pollutants’ degradation under mechanical vibration and offers a strategy for the design of other high-performance piezocatalysts.

Boosting Piezocatalytic Activity of Bi5Ti3FeO15/BiOCl Heterostructured Nanocomposites for Degrading Multiple Dyes and Antibiotics

“…In the absence of a catalyst, RhB, TH, and BPA were hardly degraded. The degradation efficiency of RhB was ∼100% in 4 h and the k value was 0.011 h –1 , which was superior to some other reported piezocatalysts, ,− as shown in Table S2. In addition, TH and BPA antibiotics were removed by 95 and 70% within 6 h under the same conditions, and the k values were 0.009 and 0.004 h –1 , respectively.…”

“…Note that the obtained k value for the Bi 5 Ti 3 FeO 15 /BiOCl (4 h) catalyst was much higher than the individual Bi 5 Ti 3 FeO 15 (0.072 min –1 ) and BiOCl (0.04 min –1 ) (Figure S2), and also larger than the sum of the Bi 5 Ti 3 FeO 15 and BiOCl catalysts, indicating the formation of a heterostructure between the Bi 5 Ti 3 FeO 15 and BiOCl catalysts rather than their physical mixture. The piezocatalytic performance of the Bi 5 Ti 3 FeO 15 /BiOCl (4 h) catalyst for degrading mixed dyes was superior to numerous reported piezocatalysts, ,− as shown in Table S1. The reasons for the enhanced piezocatalytic performance of Bi 5 Ti 3 FeO 15 /BiOCl (4 h) were attributed to the existence of oxygen vacancy and the optimized band structure, which were supported by the electrochemical measurements below.…”

“…The elemental component and chemical states of Bi 5 Ti 3 FeO 15 , BiOCl, and Bi 5 Ti 3 FeO 15 /BiOCl (4 h) were measured using X-ray photoelectron spectroscopy (XPS), and Figure a shows the survey spectra, indicating that Bi 5 Ti 3 FeO 15 and BiOCl both contained the desired elements, and Bi, Ti, Fe, and Cl elements were also observed in the Bi 5 Ti 3 FeO 15 /BiOCl (4 h) catalyst as expected. For the Bi 4f spectra of the Bi 5 Ti 3 FeO 15 catalyst, the two peaks at 158.7 and 164.03 eV were credited to Bi 4f 7/2 and Bi 4f 1/2 , indicating that Bi was Bi 3+ in Bi 5 Ti 3 FeO 15 , , as shown in Figure b. However, it was found that the binding energies of Bi shifted to higher binding energies by ∼0.1 eV in the Bi 5 Ti 3 FeO 15 /BiOCl (4 h) catalyst, manifesting the formation of the Bi 5 Ti 3 FeO 15 /BiOCl (4 h) heterostructure rather than their physical mixture.…”

Highly Efficient Piezocatalytic Activity of Poly(tetrafluoroethylene) for Large-Scale Organic Wastewater Purification

“…The piezocatalytic degradation of organic pollutants has been demonstrated by various nano-piezocatalysts, such as ZnO, BaTiO 3 , Bi 5 Ti 3 FeO 15 , , g-C 3 N 4 , , (1 – x )­Pb­(Mg 1/3 Nb 2/3 )­O 3 – x PbTiO 3 , , MoS 2 , and so on. The intrinsic factors of nano-piezocatalysts, including piezoelectric coefficient, surface area, and oxygen vacancy, have positive effects on piezocatalytic performance. − However, the nano-piezocatalysts with the above characteristics usually need expensive raw materials and a time-consuming synthesis process.…”

Tribocatalytic Degradation of Organic Pollutants Using Fe2O3 Nanoparticles

“…Mechanical energy is a kind of widely available and sustainable energy, such as wind energy, water flow, ambient noise, and vibration, which is widespread in nature. Piezoelectric materials can convert mechanical energy into chemical energy due to the piezoelectric effect, namely, piezocatalysis. − Recently, piezocatalysis has made significant progress in the application of pollutant degradation, ,, hydrogen production from water splitting, , carbon dioxide reduction, and so on. However, there are some strict requirements for piezocatalysts.…”