γ-Fe2O3/CdO/NiO/MWCNT composites for photocatalytic elimination of methylene blue and pendimethalin

Herein, γ-Fe2O3/CdO/NiO/MWCNTs (FCO@NiO/MWCNTs) composite has been fabricated by a combined approach of co-precipitation and ultrasonication method. The characterization of as-synthesized catalysts is carried out by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) analysis. XRD analysis of composite exhibits well defined peaks from both metal oxides (i.e., γ-Fe2O3, CdO, and NiO) and carbon (MWCNTs) contents. Different bond vibrations from metal-oxygen (M − O) bonds of constituting metal oxides and surface functional groups from MWCNTs were observed in FT-IR spectra of FCO@NiO/MWCNTs. Morphological examination of FCO@NiO/MWCNTs revealed co-ocuurence of snowy FCO@NiO particles with thread like MWCNTs. When applied for photocatalytic tests, FCO@NiO/MWCNTs exhibited good photocatalytic activity towards methylene blue (MB) and pendimethalin with 97.7 % and 58.8 % degradation under the sunlight, respectively. In case of MB degradation, the highest value of the kinetic rate constant (k) is 0.0242 min−1 which is 1.8, 5, and 7 times higher than FCO@NiO, γ-Fe2O3/CdO, and NiO. The excellent photocatalytic performance of FCO@NiO/MWCNTs is associated with its rational structure with multicomponent heterojunctions which ensues great charge separation capability and widens the absorption window for solar light radiations. In prospect, our study presents efficient strategy of heterojunction fabrication to enhance the intrinsic properties of materials for improved photocatalytic applications. •FCO@NiO/MWCNTs composite was fabricated by facile routes.•FCO@NiO/MWCNTs showed high photo-degradation ability against pollutants.•Improved photo-catalytic efficiency of FCO@NiO/MWCNTs is mainly due to possible heterojunction formation.