Piezo-Photocatalytic Approach for Pollutant Removal Using PZT-MgAl LDH-GO Hierarchical Nanocomposites

Abstract

Effective and recyclable water treatment technologies are crucial for practical heavy metal removal. Photocatalysis an improved oxidation process is widely used in energy production and environmental remediation. However, the reaction efficiency of photocatalysis is restricted by the rapid recombination of photogenerated electron–hole pairs, and although it is promising under solar light illumination conditions, it remains challenging because of the seasonal variations, weather conditions, and diurnal cycles. Alternatively, piezo catalysis, transferring mechanical to chemical energy, is vital for environmental cleansing and energy regeneration. Therefore, lead zirconate titanate (PZT) with a MgAl layered double hydroxide and graphene oxide (GO) is prepared herein for efficient piezo-photocatalytic. The proposed material PZT-MgAl-GO is used in combination with UV light and sonication to remove hazardous metallic Cr(VI) species. The reduction efficiencies of Cr(VI) increase in the order of PZT<MgAl-GO<PZT-MgAl-GO. The Cr(VI) amount decreases by ≈99% through a process involving both sonication and UV light exposure. The main active species for the photocatalytic reduction of Cr(VI) are assumed to be e⁻ and •O₂⁻ radicals. With these advantages a high decomposition ratio, simple preparation method, and its use under UV light and sonication PZT-MgAl-GO is considered a potential material for removing heavy metals from wastewater.