Efficient photoelectrochemical water splitting and photocatalytic performance for graphene-bridged MoS2–Fe2O3 nanocomposite under visible light active: Insights into photocatalysis mechanism

Abstract

In this work, we aim to design a new nanocomposite with an improved photocatalytic performance by the synergistic formation of a Z-scheme photocatalytic system with graphene-bridged molybdenum disulfide (MoS2) and iron oxide (Fe2O3). We fabricated graphene-bridged MoS2–Fe2O3 nanocomposites by a simple hydrothermal method for enhanced photoelectrochemical (PEC) performance and higher degradation of TC. This nanocomposite can increase carrier separation efficiency. Moreover, the photocatalysts exhibit excellent oxidation and reduction rates capabilities assessed by photocatalytic and photoelectrochemical experiments under visible light illumination. The photocatalyst showed 97% removal capability of tetracycline and photocurrent density is five times higher than of bare Fe2O3. The active specie of .O2− and ⋅OH radicals was detected by the ESR instruments during photocatalytic activity improvement that could confirm the constructed Z-scheme MoS2–Fe2O3-Graphene nanocomposite showed that two folds photocatalytic degradation greater than those of pristine MoS2 and Fe2O3. According to the results shows UV–Visible spectroscopy, photoluminescence spectroscopy, Electron impendence spectroscopy, and photocurrent response, the photo-response electrons of transfer from the conduction band of Fe2O3 could fast transport in the valence band of MoS2. The graphene bridge served as a charge-migrate channel between two materials, and the electrons in protonated MoS2 and Fe2O3 achieved a charge balance. This work provides a new strategy for further design of high-efficiency of MFG nanocomposite with graphene as the electronic mediator for environmental remediation.