Abstract
Our current study deals with the dye adsorption and electrical property of a partially carbonized composite fiber containing transition metal oxides including, iron oxide, nickel oxide, and titanium oxide. The fiber was made by electrospinning, carbonization, and hydrothermal treatment. During the electrospinning, titanium oxide particles were dispersed in polyacrylonitrile (PAN) polymer-dimethylformamide (DMF) solution. Nickel chloride and iron nitrate were added into the solution to generate nickel oxide and iron oxide in the subsequent heat treatment processes. The polymer fiber was oxidized first at an elevated temperature of 250 °C to stabilize the structure of PAN. Then, we performed higher temperature heat treatment at 500 °C in a furnace with hydrogen gas protection to partially carbonize the polymer fiber. After that, the oxide-containing fiber was coated with activated carbon in a diluted sugar solution via hydrothermal carbonization at 200 °C for 8 h. The pressure reached 1.45 MPa in the reaction chamber. The obtained product was tested in view of the dye, Rhodamine B, adsorption using a Vis-UV spectrometer. Electrical property characterization was performed using an electrochemical work station. It was found that the hydrothermally treated oxide-containing fiber demonstrated obvious dye adsorption behavior. The visible light absorption intensity of the Rhodamine B dye decreased with the increase in the soaking time of the fiber in the dye solution. The impedance of the fiber was increased due to the hydrothermal carbonization treatment. We also found that charge build-up was faster at the surface of the specimen without the hydrothermally treated carbon layer. Electricity generation under visible light excitation is more intensive at the hydrothermally treated fiber than at the one without the hydrothermal treatment. This result is consistent with that obtained from the dye adsorption/decomposition test because the charge generation is more efficient at the surface of the hydrothermally treated fiber, which allows the dye to be decomposed faster by the treated fibers with activated carbon.
Highlights
Ocean water pollution is considered a big concern because many toxic spills could enter into the ocean and kill the organisms and their habitats
The hydrothermally-treated activated carbon fiber can slow down the charge recombination kinetics of transition metal oxides
The activated carbon- or hydrochar-coated fibers demonstrate the capability of absorbing organic dyes in other colors
Summary
Ocean water pollution is considered a big concern because many toxic spills could enter into the ocean and kill the organisms and their habitats. An array of titanium oxide nanostructures on flexible carbon fiber was generated by the hydrothermal reaction of titanium compounds at 150 ◦ C. The motivation of this work is to prepare a dye adsorption flexible fiber mat containing transition metal oxide nanoparticles and an activated carbon surface layer. The nanofibers were placed in another furnace and heated up to 500 ◦ C, and purged with hydrogen gas for the purpose of partial carbonization and oxidation prevention. Some of the heat-treated nanofibers were wrapped by a piece of aluminum foil and placed in the unstirred high-pressure reactor for the purpose of hydrothermal carbonization. The data were plotted to Fibers 2019, x FOR PEER REVIEW reveal the 7,photosensitivity of the nanofiber
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
