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.

Towards practical and sustainable SERS: a review of recent developments in the construction of multifunctional enhancing substrates

“…Au NPs decorated cicada wing [233] 10 [237] unspecified concentration of malachite green, 1 µM thiram water-ethanol solution visible light photocatalytic degradation rinse with deionized water for 5 s -visible light (1000 W xenon lamp, 400-800 nm) irradiation for 50 mins -rinse with deionized water for 5 sblow dry with nitrogen gas near-full removal of analyte; slight drop off in SERS activity after each regeneration cycle, maintained more than 70% SERS activity after 5 cycles using malachite green as analyte; maintained more than 83% SERS activity using thiram as analyte MoS 2 /Fe 2 O 3 heterojunction nanocomposite [248] [253] 1.00×10 -6 M rhodamine 6G superhydrophobicity sonicated in 30 mL of deionized water for 10 mins analyte fully removed; SERS activity decreased by 17.3% after 6 cycles Si wafer decorated with hierarchical Ag nanostructures on indium oxide nano-branches [254] 2.1×10 -5 M rhodamine 6G water solution superhydrophobicity sonicated in isopropyl-alcohol bath for 10 mins SERS activity fully maintained for 10 cycles MIP@Ag [266] 1×10 -5 M bisphenol A in acetonitrile solution intermolecular interaction treatment with methanol-acetic acid solution (details unspecified)…”

“…246 Amongst these materials, enhancing substrates based on semiconductors, such as ZnO, TiO 2 , and MoS 2 , stand out particularly since they are not only potentially cheap and stable alternatives to Ag and Au but are also photocatalytically active which allows for the construction of reusable substrates. [247][248][249][250] For example, in a proof-of-concept demonstration, Liu, Gao, et al designed photocatalytically active ternary ZnO/ZnS/MoS 2 nanocomposites, as shown in Figure 17D, which could be used as reusable substrates for SERS. 251 The nanocomposites were synthesized through in-situ chemical growth using phosphomolybdic acid hydrate (PMo 12 )@zeolitic imidazolate frameworks-8 (ZIF-8) as the precursor.…”

Enhanced charge carrier separation by bi-piezoelectric effects based on pine needle-like BaTiO3/ZnO continuous nanofibers

“…Serious environmental pollution is due to population growth and rapid economic development. 1 The treatment of water pollution and the production of clean energy have become urgent needs to improve ecology. 2 Semiconductor-based photocatalysis is considered an effective method to degrade organic molecules in water and purify air.…”

Synergistic Effect of Paraffin-Incorporated In2O3/ZnO Multifold Smart Glazing Composite for the Self-Cleaning and Energy-Saving Built Environment

“… 41 A heterogeneous structure is possible by incorporating MO semiconductors with other MOs, which leads to type II heterojunctions having photocatalytic behavior. 42 Containing a higher number of oxidative radicals, both ZnO and In 2 O 3 create charge carriers at their interface may facilitate their photocatalytic performance. Besides, at a higher temperature, due to the increased transparency of the composite coating, light waves pass through and diminish any pollutants through photocatalytic reaction and antisoiling properties.…”