In situ engineering of highly conductive TiO2/carbon heterostructure fibers for enhanced electrocatalytic degradation of water pollutants

Jhen-Cih Wu; Yi-Hsueh Chuang; Sofia Ya Hsuan Liou; Qilin Li; Chia-Hung Hou

doi:10.1016/j.jhazmat.2022.128328

In situ engineering of highly conductive TiO₂/carbon heterostructure fibers for enhanced electrocatalytic degradation of water pollutants

J Hazard Mater. 2022 May 5:429:128328. doi: 10.1016/j.jhazmat.2022.128328. Epub 2022 Jan 22.

Authors

Jhen-Cih Wu¹, Yi-Hsueh Chuang², Sofia Ya Hsuan Liou³, Qilin Li⁴, Chia-Hung Hou⁵

Affiliations

¹ Graduate Institute of Environmental Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan.
² Institute of Environmental Engineering, National Yang Ming Chiao Tung University, 1001 University Road, East District, Hsinchu 30010, Taiwan.
³ Department of Geosciences, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan; Research Center for Future Earth, National Taiwan University, No. 1, Section 4. Roosevelt Rd., Taipei 10617, Taiwan.
⁴ Department of Civil and Environmental Engineering, Rice University, 6100 Main Street MS 519, Houston, TX 77005, USA; Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, 6100 Main Street MS 6398, Houston, TX 77005, USA.
⁵ Graduate Institute of Environmental Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan; Research Center for Future Earth, National Taiwan University, No. 1, Section 4. Roosevelt Rd., Taipei 10617, Taiwan. Electronic address: chiahunghou@ntu.edu.tw.

PMID: 35114455
DOI: 10.1016/j.jhazmat.2022.128328

Abstract

Rational design of nanocomposite electrode materials with high conductivity, activity, and mechanical strength is critical in electrocatalysis. Herein, freestanding, flexible heteronanocomposites were fabricated in situ by carbonizing electrospun fibers with TiO₂ nanoparticles on the surface for electrocatalytic degradation of water pollutants. The carbonization temperature was observed as a dominant parameter affecting the characteristics of the electrodes. As the carbonization temperature increased to 1000 °C, the conductivity of the electrode was significantly enhanced due to the high degree of graphitization (I_D/I_G ratio 1.10) and the dominant rutile phase. Additionally, the formation of TiO₂ protrusions and the C-Ti heterostructure were observed at 1000 °C, which contributed to increasing the electrocatalytic activity. When 1.5 V (vs. Ag/AgCl) was employed, electrocatalytic experiments using the electrode achieved 90% degradation of crystal violet and 10.9-87.5% for an array of micropollutants. The electrical energy-per-order (EEO) for the removal of crystal violet was 0.7 kWh/m³/order, indicative of low-energy requirement. The efficient electrocatalytic activity can be ascribed to the fast electron transfer and the strong ability to generate hydroxyl radicals. Our findings expand efforts for the design of highly conductive heteronanocomposites in a facile in situ approach, providing a promising perspective for the energy-efficient electrocatalytic degradation of water pollutants.

Keywords: Carbonized electrospun fibers; Electrocatalysis; Electrospinning; Heterostructure; Nanocomposite.