Z-Scheme CdIn₂S₄/Bi₂WO₆ Heterojunction for High Piezo-Photo Synergetic Performance

Abstract

The piezoelectric effect triggered by mechanical energy could establish an internal electric field to effectively modulate the separation behavior of carriers. Herein, a novel CdIn2S4/Bi2WO6 (CIS/BWO) piezo-photocatalyst for removing diclofenac (DCF) from water was constructed for the first time. Encouragingly, the photocatalytic degradation activity of CIS/BWO was effectively promoted through the piezoelectric effect. Specifically, 10% CIS/BWO exhibited promising DCF degradation performance under co-excitation of light irradiation and ultrasonic vibration, with a degradation efficiency of 99.9% within 40 min, much higher than that of pure photocatalysts (72.3%) and piezocatalysts (60.3%). Meanwhile, an in-depth study of the charge carrier separation mechanism of the CIS/BWO composite under the piezo-photo synergy condition was proposed. Both the built-in electric field induced by the piezoelectric effect in BWO and the Z-scheme transfer path of the CIS/BWO heterojunction are beneficial to interfacial charge transfer. Moreover, the Z-scheme mechanism was further demonstrated by trapping experiments and the electron spin resonance (ESR) technique. Finally, the corresponding intermediates of DCF over CIS/BWO composites and possible degradation pathways were also investigated by DFT calculations and liquid chromatography–mass spectrometry.

Band Gap Engineering and Lattice Distortion for Synergetic Tuning Optical Properties of NaNbO3 toward Enhanced Piezo-photocatalytic Activity

“…In addition, 0.10LMN will also have more free charges because the larger polarization field can produce more free charges. The larger the polarization field, the more easily the electrons in CB and the holes in VB will migrate in different directions, resulting in a greater band tilt (electrons migrate to the side of positive charges, and the holes migrate to the side of negative charges). , Afterward, the holes and electrons migrate to the surface of the material, respectively, to undergo redox reactions with the organic dyes. Electron and hole separation and reverse migration under the action of an electric field will greatly reduce their recombination rate, thus greatly improving the degradation efficiency.…”

Recent advances of piezo‐catalysis and photocatalysis for efficient environmental remediation

“…N. Li and colleagues [271] The introduction of adenine, a polar molecule, as a linking agent in the synthesis of Zr-based UiO-66 (AD-U) was pioneered by Z. Guo and team [246]. The goal of this innovative approach was to improve the asymmetrical structure and piezoelectric properties of UiO-66.…”

Piezoelectric Polarization and Sulfur Vacancy Enhanced Photocatalytic Hydrogen Evolution Performance of Bi2S3/ZnSn(OH)6 Piezo-photocatalyst

“…Comparison to traditional oxide photocatalysts TiO 2 , multi-oxides (Bi 2 WO 6 , ZnWO 4 , etc.) usually have good optical stability, diverse crystal phases, and the possibility of multiple regulation.…”