Simultaneous photocatalytic degradation of ibuprofen and H2 evolution over Au/sheaf-like TiO2 mesocrystals

Xiaxi Yao; Xiuli Hu; Yi Liu; Xuhong Wang; Xuekun Hong; Xuefeng Chen; Suresh C Pillai; Dionysios D Dionysiou; Dawei Wang

doi:10.1016/j.chemosphere.2020.127759

Simultaneous photocatalytic degradation of ibuprofen and H₂ evolution over Au/sheaf-like TiO₂ mesocrystals

Chemosphere. 2020 Dec:261:127759. doi: 10.1016/j.chemosphere.2020.127759. Epub 2020 Jul 23.

Authors

Xiaxi Yao¹, Xiuli Hu¹, Yi Liu¹, Xuhong Wang¹, Xuekun Hong¹, Xuefeng Chen², Suresh C Pillai³, Dionysios D Dionysiou⁴, Dawei Wang⁵

Affiliations

¹ School of Materials Engineering, Changshu Institute of Technology, Changshu, 215500, PR China.
² Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050, PR China.
³ Nanotechnology and Bio-Engineering Research Division, Department of Environmental Science, Faculty of Science, Institute of Technology Sligo, Ash Lane, Sligo, Ireland.
⁴ Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, OH, 45221, USA.
⁵ Department of Environmental Science and Earth Sciences, Clemson University, Clemson, SC, 29634, USA; Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China. Electronic address: dwang4@clemson.edu.

PMID: 32731028
DOI: 10.1016/j.chemosphere.2020.127759

Abstract

Considerable effort has been devoted to the efficient degradation of pharmaceuticals and personal care products (PPCPs), while the chemical energy in these processes has been widely overlooked. In this study, we demonstrated the simultaneous hydrogen production and ibuprofen degradation through heterogeneous photocatalysis. By anchoring Au nanoparticles (NPs) on the (101) surface of sheaf-like TiO₂ mesocrystals with [001] orientation, efficient charge separation is achieved, which is essential for the photocatalytic redox reactions. XPS analysis showed that the binding energies of Ti 2p and O 1s indicated no shift after Au addition. Peaks observed at 81.8 and 85.5 eV due to Au 4f_7/2 and Au 4f_5/2 of metallic gold on the surface of Au/meso-TiO₂, confirmed the formation of Au NPs. The as-synthesized anatase TiO₂ mesocrystals are composed of small nanocrystals with a size of 8 nm and exhibit the uniform sheaf-like morphology along [001] orientation. As expected, the 1 wt% Au/TiO₂ mesocrystals shows the largest photocurrent density, highest H₂-evolution rate, and fastest photodegradation rate of ibuprofen under simulated sunlight irradiation among all the studied catalyst. Furthermore, the effect of solution pH, common anions (Cl^-, NO₃^-, and SO₄^2-) and cations (Na⁺, K⁺, and Ca²⁺) on photocatalytic H₂ evolution and degradation of ibuprofen were individually investigated and discussed. A mechanism for the simultaneous photocatalytic hydrogen generation and degradation of ibuprofen has also been proposed. This work opens up new opportunities for the development of energy efficient techniques for PPCPs degradation.

Keywords: (101) surface; Au/TiO(2) mesocrystal; Hydrogen production; PPCPs degradation.

MeSH terms

Catalysis
Gold / chemistry*
Hydrogen / analysis*
Ibuprofen / analysis*
Metal Nanoparticles / chemistry*
Models, Theoretical
Particle Size
Photolysis
Sunlight*
Surface Properties
Titanium / chemistry*
Water Pollutants, Chemical / analysis*

Substances

Water Pollutants, Chemical
titanium dioxide
Gold
Hydrogen
Titanium
Ibuprofen