Efficient piezocatalytic removal of BPA and Cr(VI) with SnS2/CNFs membrane by harvesting vibration energy

Photodeposition of CoOx nanoparticles on BiFeO3 nanodisk for efficiently piezocatalytic degradation of rhodamine B by utilizing ultrasonic vibration energy

“…The 3CoO x /BiFeO 3 composite generates a higher piezoelectric current than BiFeO 3 . This result definitely proves that the decoration of CoO x promotes the separation of piezoelectric induced charge carriers in the BiFeO 3 [67] , [68] , and agrees well with the suggested mechanism in Fig. 8 .…”

The Mechanism of Piezocatalysis: Energy Band Theory or Screening Charge Effect?

“…[24] Ap roposed indirect method for the excitation of mechanical energy is that the energized electrons and holes within the piezocatalyst result from vibration-induced thermal excitation, from which the ultrasonic cavitation collapse would lead to energy release and produce al ocal "hot spot" (about 5000 8 8C) near the piezocatalysts;s uch ah igh temperature would excite electrons. [20,25] In short, it would be of scientific importance if the above theory could be firmly confirmed. Most piezoelectric materials usually have aw ide band gap and are photo-inert; the successful implementation of mechanical excitation may provide ac omplementary approach for applications in some specific areas where photocatalysis fails.…”

“…[22] Thep hotogenerated carriers (electrons and holes) can initiate redox reactions, depending on the energy band levels.Nevertheless,the source of the reactive carriers in piezocatalysis arises from excitation by mechanical energy or the intrinsic free charges in the material, at opic which is still under debate. [20,23] In terms of the mechanical excitation approach, apreliminary hypothesis was firstly proposed that am echanical force such as ultrasonication can directly excite the electrons from the VB to the CB since the collapse of ultrasonic-induced cavitation bubbles can inflict ahigh pressure of up to 10 8 Pa at the heterogeneous catalyst/water interface,a nd this provides sufficient energy for electron excitation (Figure 2a). [24] Ap roposed indirect method for the excitation of mechanical energy is that the energized electrons and holes within the piezocatalyst result from vibration-induced thermal excitation, from which the ultrasonic cavitation collapse would lead to energy release and produce al ocal "hot spot" (about 5000 8 8C) near the piezocatalysts;s uch ah igh temperature would excite electrons.…”

Perspective on the development of high performance flexible piezoelectric energy harvesters

“…Besides photocatalysis, the piezocatalysis process is emerging as an effective way to environmental remediation. [159][160][161][162] Tian et al have shown piezocatalytic removal of bisphenol A (BPA) and hexavalent chromium (Cr(VI)) with a SnS 2 / CNFs membrane by harvesting vibration energy. 161 The authors have shown boosted piezocatalytic removal using ultrasonic vibration as compared to that with just optical illumination.…”