Biogenic synthesis of a green tea stabilized PPy/SWCNT/CdS nanocomposite and its substantial applications, photocatalytic degradation and rheological behavior

Abstract

A green tea leaf-derived cadmium sulfide quantum dot-based system containing different weight percentages of single-walled carbon nanotubes (SWCNTs) and polypyrrole, named PSC, was designed via a green method. The photocatalytic degradation of Ponceau BS dye (λ_max 505 nm) in the presence of PSC was measured. PSC with the highest weight percentage of SWCNTs (7-PSC) showed maximum photocatalytic activity, with 94.6% dye degradation in 55 minutes of irradiation time. This significant enhancement was due to the synergism in the intrinsic properties of the parent components. Alongside this, the rheological behavior of the prepared nanomaterial PSC was examined at constant (100 s⁻¹) and varying shear rate from 0 to 500 s⁻¹ at a fixed temperature of 25 °C for a specified volume percentage of 0.1% using Castrol class: 15W-40 engine oil as a base fluid. The objective of lowering the viscosity of engine oil by 98.9% (initial: 0.221000 Pa s, final: 0.0022 Pa s.) was achieved by chartering/mixing the prepared PSC nanomaterial into the engine oil. A comparative study of the experimental and simulation outputs implied the high precision of the modeling via a neural network with minute 0.373 average % errors.