N-doped ZnO–MoS₂ binary heterojunctions: the dual role of 2D MoS₂ in the enhancement of photostability and photocatalytic activity under visible light irradiation for tetracycline degradation

Abstract

In this work, we report the fabrication of binary semiconductor heterojunctions comprising of N-doped ZnO nanorods loaded with two-dimensional MoS 2 nanoflowers in varying amounts, using a facile hydrothermal synthesis method. These semiconductor heterojunctions have been demonstrated as highly efficient photocatalysts with enhanced performance under visible light irradiation for the degradation of a pharmaceutical pollutant, tetracycline. The superior photocatalytic activity of the heterojunctions can be attributed to the synergistic effect of Ndoping of ZnO and loading of MoS 2 leading to higher absorption of visible light, efficient separation of photo generated charge carriers and rapid charge transfer to reaction sites, as per the conduction band potentials of both N-doped ZnO and MoS 2 . In addition, the twodimensional nanoflower morphology of MoS 2 provides more reaction sites for the adsorption of pollutant, due to its large surface area. Furthermore, the transfer of holes from the valence band of N-doped ZnO to the valence band of MoS 2 prevents the photocorrosion of N-doped ZnO resulting in enhanced photostability of the catalyst during the reaction.

Stimulated Electrocatalytic Hydrogen Evolution Activity of MOF‐Derived MoS2 Basal Domains via Charge Injection through Surface Functionalization and Heteroatom Doping

“…Specifically, Zn in MoS-CoS-Zn possesses higher peak intensity and positive shift in the absorption edge compared with MoS-CoS-Zn-1pot (Figure 4d inset), which suggests that Zn is more positively charged, and therefore more electron transfer could occur from Zn to MoS-CoS hybrid in MoS-CoS-Zn, coinciding with the XPS spectra data. [44][45][46] To further reveal the electronic environment modulation, and to verify the Zn atom coordination, X-ray absorption fine structure measurements on Co ( Figure S25, Supporting Information) and Mo K-edges ( Figure S26, Supporting Information) were also carried out. This finding is corroborated by Fourier-transformed EXAFS (FT-EXAFS) spectra of MoS-CoS-Zn, MoS-CoS-Zn-1pot, and ZnS.…”

Highly Efficient Visible Light Active 2D‐2D Nanocomposites of N‐ZnO‐g‐C3N4 for Photocatalytic Degradation of Diverse Industrial Pollutants

“…Similarly, Katsumata and coworkers reported a highly efficient visible light active nanocomposite by coupling g‐C 3 N 4 with Ag 3 PO 4 with enhanced photocatalytic efficiency for dye removal from water. In addition to this, recent works of our group have utilized ZnO based nanocomposites for industrial and pharmaceutical pollutant removals including organic dyes (methylene blue, methyl orange), tetracycline antibiotic and carbendazim, a hazardous fungicide . In the view of further improvement of charge transfer kinetics by exploiting high catalytic surface area, we have focused our study towards the fabrication of 2D‐2D nanosheet nanocomposites.…”

“…In this work, we have designed and fabricated 2D‐2D nanosheet nanocomposites of g‐C 3 N 4 loaded with varying amounts of N‐doped ZnO. N‐doping can enhance the visible light response by introducing defect state near the valence band (VB) top wherein the photoexcited electrons are promoted from VB of ZnO . N is considered as one of best alternate to substitute O because of similar atomic size and electronegativity, so there could be significant overlap between p‐orbital of N with VB O‐2p orbital, which is helpful in suppressing photogenerated charge carriers’ recombination .…”

“…N‐doping can enhance the visible light response by introducing defect state near the valence band (VB) top wherein the photoexcited electrons are promoted from VB of ZnO . N is considered as one of best alternate to substitute O because of similar atomic size and electronegativity, so there could be significant overlap between p‐orbital of N with VB O‐2p orbital, which is helpful in suppressing photogenerated charge carriers’ recombination . All prepared 2D‐2D nanocomposites of N‐ZnO‐g‐C 3 N 4 have been utilized as efficient photocatalysts for the degradation of diverse industrial pollutants, such as Rhodamine B (RhB), thiabendazole (TBZ), nitrobenzene (NB), and tetracycline (TC), under visible light irradiation.…”

Heteroatom‐Doped Carbonaceous Photocatalysts for Solar Fuel Production and Environmental Remediation

“…Indeed, the doping by heteroatoms has attracted great interest in fabricating advanced photocatalysts including both non-metallic photocatalysts, [1,4,[7][8][9][10][77][78][79][80][81][82][83][84] and metallicp hotocatalysts. [84][85][86][87][88][89][90][91][92][93][94][95] In this Review,w ef ocus on the non-metallic heteroatoms-doped carbonaceous photocatalysts for energy conversion and environmental remediation applications. He is the head of the "Advanced Catalytic Materials" research group, DUT.In2 012, he was awarded the "Program for New Century Excellent Ta lents in University" by the Chinese Ministry of Education.…”