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.