Surface plasma Ag-decorated single-crystalline TiO2-x(B) nanorod/defect-rich g-C3N4 nanosheet ternary superstructure 3D heterojunctions as enhanced visible-light-driven photocatalyst

Junyan Kuang; Zipeng Xing; Junwei Yin; Zhenzi Li; Qi Zhu; Wei Zhou

doi:10.1016/j.jcis.2019.01.124

Surface plasma Ag-decorated single-crystalline TiO_2-x(B) nanorod/defect-rich g-C₃N₄ nanosheet ternary superstructure 3D heterojunctions as enhanced visible-light-driven photocatalyst

J Colloid Interface Sci. 2019 Apr 15:542:63-72. doi: 10.1016/j.jcis.2019.01.124. Epub 2019 Jan 30.

Authors

Junyan Kuang¹, Zipeng Xing², Junwei Yin¹, Zhenzi Li³, Qi Zhu⁴, Wei Zhou⁵

Affiliations

¹ Department of Environmental Science, School of Chemistry and Materials Science, Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, PR China.
² Department of Environmental Science, School of Chemistry and Materials Science, Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, PR China. Electronic address: xingzipeng@hlju.edu.cn.
³ Department of Epidemiology and Biostatistics, Harbin Medical University, Harbin 150086, PR China.
⁴ Department of Environmental Science, School of Chemistry and Materials Science, Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, PR China. Electronic address: hdzhuqi@hlju.edu.cn.
⁵ Department of Environmental Science, School of Chemistry and Materials Science, Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, PR China. Electronic address: zhouwei1@hlju.edu.cn.

PMID: 30731354
DOI: 10.1016/j.jcis.2019.01.124

Abstract

Ag-TiO_2-x(B)/g-C₃N₄ ternary heterojunctions photocatalysts are fabricated by hydrothermal-calcination, photo-deposition procedure, and followed by in-situ solid-state chemical reduction procedure. As-obtained photocatalysts are consisted with heterojunctions between 2D g-C₃N₄ sheets and 1D TiO₂(B) single-crystalline nanorods. The band gap of Ag-TiO_2-x(B)/g-C₃N₄ ternary heterojunctions photocatalysts is reduced to ∼2.23 eV due to plasma Ag and surface engineering. Under visible light irradiation, it has an optimal photocatalytic property for the reduction of Cr⁶⁺ (95%) and degradation of NH₄⁺ (93%). The apparent reaction rate constants (k) of ternary heterojunctions photocatalysts for NH₄⁺ and Cr⁶⁺ are 25 and 12 folds higher than that of original TiO₂(B). Furthermore, Ag-TiO_2-x(B)/g-C₃N₄ also has excellent hydrogen production efficiency, which is up to 410 µmol h^-1 g^-1. This enhancement can be attributed to the unique heterojunction formed by 1D single-crystalline TiO₂(B) nanorods and 2D g-C₃N₄ sheets, surface plasma resonance effect of plasma Ag nanoparticle, and surface engineering. A possible photocatalytic mechanism is also proposed by analysizing the XPS valence-band spectra and the Mott-Schottky.

Keywords: Heterojunction; Single-crystalline TiO(2)(B) nanorod; Surface engineering; Visible-light-driven photocatalysis; g-C(3)N(4) sheet.