Self-cleaning semiconductor heterojunction substrate: ultrasensitive detection and photocatalytic degradation of organic pollutants for environmental remediation

Abstract

Emerging technologies in the field of environmental remediation are becoming increasingly significant owing to the increasing demand for eliminating significant amounts of pollution in water, soil, and air. We designed and synthesized MoS2/Fe2O3 heterojunction nanocomposites (NCs) as multifunctional materials that are easily separated and reused. The trace detection performance of the prepared sample was examined using bisphenol A (BPA) as the probe molecule, with limits of detection as low as 10(-9)M; this detection limit is the lowest among all reported semiconductor substrates. BPA was subjected to rapid photocatalytic degradation by MoS2/Fe2O3 NCs under ultraviolet irradiation. The highly recyclable MoS2/Fe2O3 NCs exhibited photo-Fenton catalytic activity for BPA and good detection ability when reused as a surface-enhanced Raman scattering (SERS) substrate after catalysis. The SERS and photocatalysis mechanisms were proposed while considering the effects of the Z-scheme charge-transfer paths, three-dimensional flower-like structures, and dipole-dipole coupling. Moreover, the prepared MoS2/Fe2O3 NCs were successfully applied in the detection of BPA in real lake water and milk samples. Herein, we present insights into the development of MoS2/Fe2O3 materials, which can be used as multifunctional materials in chemical sensors and in photocatalytic wastewater treatments for the removal of recalcitrant organic pollutants. Nanomaterials: environmental remediationPhotocatalytic MoS2/Fe2O3 heterojunction nanocomposites are able to remove organic pollutants from wastewater under ultraviolet light. Material systems are needed that can remove organic pollutants from the environment, many of which are driven by photocatalysis. As well as the challenge of efficiently removing contaminants from the environment, the photocatalytic material must also be recovered afterwards. Here, a team led by Jinghai Yang from Jilin Normal University report a MoS2/Fe2O3 nanocomposite that photocatalytically degrades bisphenol A under ultraviolet irradiation. Their semiconducting composite can also function as an effective SERS catalysis for bisphenol A. Compared to the component materials - MoS2 and Fe2O3 - the rate of degradation and sensitivity of the nanocomposite were both enhanced, and could be recovered from a solution via the use of a magnetic field.