Efficient degradation of tetracycline by RGO@black titanium dioxide nanofluid via enhanced catalysis and photothermal conversion

Dahai Zhu; Li Cai; Zhuyu Sun; Ai Zhang; Paul Héroux; Hyunjung Kim; Wei Yu; Yanan Liu

doi:10.1016/j.scitotenv.2021.147536

Efficient degradation of tetracycline by RGO@black titanium dioxide nanofluid via enhanced catalysis and photothermal conversion

Sci Total Environ. 2021 Sep 15:787:147536. doi: 10.1016/j.scitotenv.2021.147536. Epub 2021 May 5.

Authors

Dahai Zhu¹, Li Cai², Zhuyu Sun¹, Ai Zhang¹, Paul Héroux³, Hyunjung Kim⁴, Wei Yu⁵, Yanan Liu⁶

Affiliations

¹ College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China.
² School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China.
³ Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Canada.
⁴ Department of Mineral Resources and Energy Engineering & Department of Environment and Energy, Jeonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju, 54896, Jeonbuk, Republic of Korea.
⁵ School of Environmental and Materials Engineering, College of Engineering, Shanghai Polytechnic University, Shanghai 201209, PR China.
⁶ College of Environmental Science and Engineering, Donghua University, Shanghai 201620, PR China. Electronic address: liuyanan@dhu.edu.cn.

PMID: 33992942
DOI: 10.1016/j.scitotenv.2021.147536

Abstract

The applications of photocatalytic pollutant degradation have remained limited due to the low efficiency of solar energy utilization. In this study, a photothermal catalyst consisting of reduced graphene oxide @ black TiO₂ (RGO@BT) nanofluid with effective full-spectrum (from ultraviolet to infrared light) absorption was synthesized by a typical two-step method of high temperature calcination and hydrothermal method. Moreover, the photothermal catalytic performance of the RGO@BT nanofluid on tetracycline was verified. Compared with individual processes (i.e, photocatalysis and thermocatalysis), the photothermal catalytic process significantly enhanced tetracycline degradation under simulated global standard spectrum sunlight (AM 1.5G, 1000 W m^-2). The maximum photothermal conversion efficiency reached 91.8%, which resulted in 94.7% tetracycline degradation (40 mg L^-1) after 120 min of treatment with 200 mg L^-1 RGO@BT nanofluid. Holes, OH, and O₂^- were found to be the main active species during the photothermal catalytic process. Moreover, heat was spontaneously converted from light energy without the use of any external energy source. The elevated system temperature facilitated the tetracycline degradation based on the Arrhenius behavior. These findings provide insights into the improvement of photocatalytic efficiency in organic contaminant degradation via solar energy-efficient photothermal conversion materials.

Keywords: Nanofluid; Photothermal catalysis; Photothermal conversion; RGO@BT; Tetracycline.

MeSH terms

Catalysis
Graphite*
Humans
Light
Titanium

Substances

graphene oxide
titanium dioxide
Graphite
Titanium