Nanoscale modification of carbon fibers with CdS quantum-dot sensitized TiO2: Photocatalytic and photothermal evaluation under visible irradiation

Abstract

A facile and efficient route is realized to evolve visible light photocatalytic and photothermal activity in the carbon fibers (CFs) network. Nanoscale CdS quantum-dots (QDs) were first deposited on TiO2 NPs, and then the resultant nanocomposite i.e. TiO2–CdS was deposited on CFs network, resulting in an efficient TiO2–CdS-CFs composite. It enabled us to make use of electron-hole generation produced inside CdS QDs under visible light irradiation, resulting in three times higher degradation of RhB dye taken as a reference organic pollutant. Interestingly, the deposition of TiO2–CdS significantly lowered the adsorption of RhB dye on CFs and increased the dye degradation rate (i.e. Kc = 0.01784 min−1). In this work, we have strategically differentiated between the dye adsorption and degradation statistics taking place in TiO2–CdS-CFs/RhB system, presenting a newer dimension to develop photocatalytic materials and/or membranes. Moreover, the photothermal response of each material was determined to envision the water purification tendency of CFs after nanoscale modification by TiO2–CdS nanocomposite, exhibiting ∼25% decrease in the weight of water via evaporation. Increased water evaporation was credited to the increase in the temperature of the water linked with the presence of TiO2–CdS over CFs. Our study demonstrates the potential of CdS QDs-sensitized TiO2 nanocomposites combined with CFs for concomitant photocatalytic and photothermal water purification, which can further be optimized and extended to devise superior combinations of similar nature. © 2022 Elsevier Ltd