Highly efficient photocatalytic degradation of rhodamine B by immobilizing CdS quantum dots on ZnCr-layered double hydroxide nanosheets

Abstract

The removal of Rhodamine B (RhB), a commonly encountered cationic dye in heavily contaminated wastewater streams, from wastewater effluents presents a significant challenge. Herein, we focus on developing an innovative ternary nanocomposite of zinc oxide nanoparticles, quantum dots of cadmium sulfide (CdS QDs), and zinc-chromium carbonate layered double hydroxide nanosheets (ZnCr–CO3-LDH NSs) via a sonochemical synthesis route. The synthesized ternary nanocomposite, CdS QDs@ZnO/ZnCr–CO3-LDH referred to as CZC-LDH, exhibits remarkable photodegradation performance of rhodamine B (RhB) dye under UV-A radiation. A comprehensive investigation into the photocatalytic efficiency and characteristics of CZC-LDH was conducted using various analytical techniques, including XRD, FESEM, DRS, XPS, HR-TEM, PL, and BET (surface area analysis). Results indicate that CZC-LDH demonstrates superior photocatalytic efficiency, achieving 98.26 % degradation of RhB within 3-h only. Moreover, the influence of different scavengers on CZC-LDH photocatalytic efficiency was evaluated to elucidate the plausible RhB photocatalytic degradation pathway. The as-prepared CZC-LDH exhibits exceptional photocatalytic performance, stability, and reusability, positioning it as a promising candidate to previously reported photocatalysts in literature.