Visible-light photocatalysis by carbon-nano-onion-functionalized ZnO tetrapods: degradation of 2,4-dinitrophenol and a plant-model-based ecological assessment

Abstract

The visible-light-induced photocatalytic performance of a three-dimensional (3D) hybrid composite based on carbon nano-onion (CNO)-functionalized zinc-oxide tetrapods (T-ZnO) was investigated to study the photocatalytic degradation of 2,4-dinitrophenol (DNP). The hybrid CNO-functionalized T-ZnO 3D composite was successfully developed via a facile one-step process. The CNOs, synthesized via a green route from flaxseed oil, were decorated on the surface of T-ZnO via chemical mixing. Such a hybrid composite allows for the complete optimization of the T-ZnO/ CNO interface to enhance visible-light harvesting, contributing to effective visible-light-induced photocatalysis. The enhanced photocatalytic performance of the T-ZnO-CNO 3D composite is attributed to the strong synergistic effects obtained by the unique cumulative intrinsic properties of CNOs and the 3D architecture of T-ZnO, which lead to exceptional charge transfer and separation. A reaction mechanism for the degradation of DNP is proposed based on a bandgap analysis and trapping experiments. Furthermore, the photocatalyst maintains a favorable reusability during consecutive cycling experiments. The ecological assessment of the photocatalytic process was performed via the germination of common gram seeds (Cicer arietinum) and reveals the low toxicity and environmental safety of the synthesized hybrid 3D composite. The observations confirm that the synthesized hybrid 3D composite facilitates wastewater decontamination using photocatalytic technology and highlights the broad implications of designing multifunctional materials for various advanced applications.

Methylene Blue Photodegradation under Visible Irradiation on Ag-Doped ZnO Thin Films

“…Jayswal and Moirangthem reported a k app value of 5:9 × 10 -3 min -1 for photocatalytic degradation of methyl orange after 150 min under visible light irradiation using an SnS/ZnO heterostructure as a photocatalyst [66]. In another study, Park et al reported a k app value of 2:7 × 10 -3 min -1 for photocatalytic degradation of 2,4-dinitrophenol after 140 min under visible light irradiation using functionalized zinc oxide tetrapods as photocatalysts [67]. Türkyilmaz et al reported a k app value of 7:5 × 10 -3 min -1 for visible light photocatalytic degradation of tartrazine after 150 min using Fe-doped ZnO as photocatalysts [22].…”

Assessment of synthesis approaches for tuning the photocatalytic property of ZnO nanoparticles

“…Conventional techniques [3], employed for the removal of water pollutants, suffer from several disadvantages like high cost, accumulation of toxic sludge, environmental pollution, and others. An alternative to these techniques is photocatalysis [4] using semiconductor nanomaterials (SNMs), which efficiently degrades organic wastes, such as dyes, drugs, etc. from aqueous media [5][6][7][8][9][10].…”

Synthesis of Conductive Carbon Aerogels Decorated with β-Tricalcium Phosphate Nanocrystallites

“…In particular, carbon-based composite materials have emerged as potentially promising targets for growth of electroactive tissues such as cardiac muscle, nerve and bone since the stimulation of osteogenesis due to inherent piezoelectric features of bone tissues attainable on conductive scaffolds [5][6][7][8][9] . Among these, blended composites between nanostructured carbon materials (carbon nanofibers/nanotubes and graphene) and biocompatible polymers (poly(vinyl alcohol), alginate, poly(lactide-co-glycolide and collagen) have been widely investigated as future materials for tissue engineering [10][11][12][13][14][15][16][17] . However, it is often essential to use a substantial amount of nanostructured carbons as a major component for achieving high conductivity in the composites.…”