Enhanced Photocatalytic Activity of ZnO–CdS Composite Nanostructures towards the Degradation of Rhodamine B under Solar Light

Abstract

A simple chemical precipitation route was utilized for the synthesis of ZnO nanoparticles (NPs), CdS NPs and ZnO–CdS nanocomposites (NCs). The synthesized nanostructures were examined for the crystal structure, morphology, optical properties and photodegradation activity of rhodamine B (RhB) dye. The ZnO–CdS NCs showed a mixed phase of hexagonal wurtzite structure for both ZnO NPs and CdS NPs. Pure ZnO NPs and CdS NPs possessed bandgaps of 3.2617 and 2.5261 eV, respectively. On the other hand, the composite nanostructures displayed a more narrow bandgap of 2.9796 eV than pure ZnO NPs. When compared to bare ZnO NPs, the PL intensity of near-band-edge emission at 381 nm was practically suppressed, suggesting a lower rate of photogenerated electron–hole (e−/h+) pairs recombination, resulting in enhanced photocatalytic activity. Under solar light, the composite nanostructures displayed a photodegradation efficiency of 98.16% towards of RhB dye. After four trials, the structural stability of ZnO–CdS NCs was verified.

Z‐scheme CuSbS2/ZnO Heterojunction for Enhanced Photocatalytic Degradation of RhB

“…Moreover, in order to further gain information on kinetics curve from the pure CAS, ZnO, and as-prepared samples for ZnO/AgFeO 2 100 10 (250) LED lamp (50 W) 300 58 [31] ZnO-MoS 2 /BiVO 4 / 10 (300) visible light 180 97 [32] ZnO/CdS 10 10 (100) solar simulator (100 W) 80 98 [33] ZnO/CuSbS 2 20 10 (60) solar simulator (100 W) 120 100 In this work…”

Facile Synthesis, Characterization, and Photocatalytic Activity of Hydrothermally Grown Cu2+-Doped ZnO–SnS Nanocomposites for MB Dye Degradation

“…Xu et al demonstrated that ZnO-SnO 2 hierarchical nanostructures, synthesized by a simple two-step microwave-assisted hydrothermal process, resulted in an effective photocatalytic degradation performance of 97.9% on MB dye [16]. Gurugubelli et al reported enhanced photocatalytic performance of ZnO-CdS nanocomposites in the degradation of RhB dye under solar light and found that the composite nanostructures exhibited superior degradation efficiency compared to bare ZnO and CdS nanoparticles [17]. Makama et al reported the microwave pulse-assisted synthesis of ZnO-SnS 2 nanocomposites for the degradation of MB dye under solar light, with 98.2% degradation efficiency [18].…”

Ultrasonic-Assisted Synthesis of CdS/Microcrystalline Cellulose Nanocomposites With Enhanced Visible-Light-Driven Photocatalytic Degradation of MB and the Corresponding Mechanism Study

“…For developing efficient visible-light-active photocatalyst, CdS is one of the extensively studied semiconductor materials because its bandgap matches well with the spectrum of visible light ( Cheng et al, 2018 ; Liu et al, 2021 ). However, the photocatalytic efficiency of CdS is fairly poor by reason of the fast recombination of photo-generated holes and electrons ( Gurugubelli et al, 2022 ). Additionally, CdS nanoparticles are prone to encounter photocorrosion, namely, the surface sulfide ions can be oxidized to sulfur by photogenerated holes under the irradiation ( Ning and Lu, 2020 ).…”