Abstract
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•Direct dual Z-scheme ZnO-Ho2O3-Sm2O3, PANI-ZnO-Ho2O3-Sm2O3, and rGO-ZnO-Ho2O3-Sm2O3 (NCR) heterostructure nanocomposites were fabricated via co-precipitation and ultra-sonication routes.•Good reusability, substantial stability, and high photodegradation efficiency for MB, MR, and P-Nitro dyes under sunlight, by rGO anchored photocatalyst.•The higher antibacterial performance of rGO-ZnO-Ho2O3-Sm2O3 against E. coli, S. aureus, and P. vulgarisbacterial strains.•The charge carrier separation and transmission were synergistically boosted by Z-scheme and rGO sheet.
In this work, a direct dual Z-scheme ZnO-Ho2O3-Sm2O3 (NC), polyaniline PANI-ZnO-Ho2O3-Sm2O3 (NCP), and reduced graphene oxide rGO-ZnO-Ho2O3-Sm2O3 (NCR) heterostructure nanocomposites were fabricated successfully. The XRD diffractograms confirmed that ZnO has hexagonal, while Ho2O3, and Sm2O3 have cubic phases in all grown composites. FTIR data exhibited the existence of the PANI, rGO, and metal–oxygen vibration. Raman spectra revealed the presence of optical phonon modes of individual oxides in nanocomposites. PL results disclose the lower charge carrier recombination rate in NCR. SEM images confirmed the anchoring of roughly spherical nanoparticles of NC with PANI and rGO. The UV–Vis analysis showed that the optical energy bandgap was 2.95 eV, 2.88 eV, and 2.81 eV for NC, NCP, and NCR, respectively. The EIS results exhibited a lower charge transfer resistance of NCR than others. The photocatalytic performance against MB, MR, and P-Nitro dyes under sunlight exhibited NCR > NCP > NC efficiency for all dyes in 60 min. The recyclability tests have confirmed the reusability upto six cycles. The antibacterial activity against E. coli, S. aureus, and P. Vulgarisbacteria displayed a higher activity for NCR. The boosted photocatalytic and antibacterial performance of NCR have ascribed the existence of Z-scheme supported with rGO, promote electron/hole separation and hinder the charge carrier’s recombination. The results clearly demonstrate that the as-grown nanocomposites can be used as an effective material for bacterial disinfection and wastewater treatment.