MoS₂ Nanoflowers Decorated on Graphene Aerogels for Visible-Light-Driven Photocatalytic Degradation of Tetracycline

Abstract

The transformation of recalcitrant pharmaceutical pollutants into products with diminished concerns via heterogeneous photocatalysis has gained considerable momentum over the past several years. However, practical applications of most semiconductor-based photocatalysts are severely restricted, attributed to insufficient visible light response pertaining to their wide band gap, ultrafast recombination of the photogenerated charge carriers, and issues corresponding to retrieval for persistent usage. Herein, rosette-like molybdenum disulfide (MoS 2 ) nanoflowers are directly grown on the interpenetrating networks of graphene aerogels (GAs) through a facile one-step hydrothermal method, and the resulting lightweight, self-supporting composites are systematically assessed for the photocatalytic degradation of tetracycline (TC). Notably, after 120 min of exposure to visible light, ∼91% of TC is degraded over the MoS 2 /GAs, which is severalfold higher than pristine MoS 2 , standalone GA, and other contemporary photocatalysts. Based on the radical quenching assay, hydroxyl radicals and superoxide anions are the principal mediators of the photocatalytic dissociation of TC. Furthermore, the primary intermediates and residual products of the photocatalytic breakdown of TC are distinguished, and a conceivable disintegration pathway is proposed. Besides, these tailor-made hybrid aerogels can be recuperated easily and successfully reused over multiple cycles, suggesting their widespread consideration in photocatalytic wastewater treatment.

Economically viable N-doped graphene aerogel for the photodegradation of structurally different dyes and a plant-model-based environmental assessment

“…2d). 62 The disordered structure of randomly oriented graphene in N-GA can be confirmed by the slightly higher intensity of the D band at 1355 cm −1 attributed to the high density of sp 3 carbon atoms. The G band shows the in-plane stretching of sp 2 carbon atoms in N-GA.…”

Aerogels Made of Few-Layer WS2 Nanosheets and Nitrogen-Doped Graphene for Photocatalytic Degradation of Caffeine

“…Additionally, UV–visible diffuse-reflectance spectra were recorded to decipher the optoelectronic properties of the WNGAs. Attributed to their blackbody behavior, our hybrid aerogels exhibit remarkable abilities to absorb photons in the visible-light component of the electromagnetic spectrum (Figure a). While there is no variation in the spectral reflectance with the wavelength among the samples, their light absorption profile overlaps well with the emission spectrum of the lamp, mounted in the photocatalytic reactor (Figure S1).…”

“…Attributed to their extremely light weight, such composite aerogels generally float at the air–water interface, aiding both effective light penetration and facile generation of electron–hole pairs . Moreover, their interconnected porous networks not only allow the multireflection of incident light but also enable optimal spatial separation of the photoinduced charge carriers by curtailing the charge migration distance. , Higher photocatalytic ability and faster degradation rates can thus be achieved along with other noteworthy benefits, such as ease of application and convenience of retrieval after the decontamination process.…”

CoP3 Quantum Dots Decorated on CdZnS Nanorods as Z-Scheme p–n Heterojunctions for Photocatalytic H2 Production

“…At the same time, the transfer mode of the Z-scheme mechanism is also conducive to the rapid separation and transfer of electron–hole pairs. The special nanorods composed of flower-like structures also provide larger reaction areas and sufficient active sites for the reaction . The hydrogen production rate of the composite catalyst is 87.4 mmol g –1 h –1 with decorated CoP 3 , which is 33 times greater than that of CdZnS.…”