Hollow Square RodLike Microtubes Composed of Anatase Nanocuboids with Coexposed {100}, {010}, and {001} Facets for Improved Photocatalytic Performance

Yi-En Du; Xianjun Niu; Jing He; Leng Liu; Yufang Liu; Changdong Chen; Xiaojing Yang; Qi Feng

doi:10.1021/acsomega.0c01827

Hollow Square RodLike Microtubes Composed of Anatase Nanocuboids with Coexposed {100}, {010}, and {001} Facets for Improved Photocatalytic Performance

ACS Omega. 2020 Jun 2;5(23):14147-14156. doi: 10.1021/acsomega.0c01827. eCollection 2020 Jun 16.

Authors

Yi-En Du^{1

2

3}, Xianjun Niu¹, Jing He¹, Leng Liu¹, Yufang Liu¹, Changdong Chen⁴, Xiaojing Yang², Qi Feng³

Affiliations

¹ School of Chemistry & Chemical Engineering, Jinzhong University, Jinzhong 030619, China.
² Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Beijing Normal University, Beijing 100875, China.
³ Department of Advanced Materials Science, Faculty of Engineering, Kagawa University, 2217-20 Hayashi-cho, Takamatsu-shi 761-0396, Japan.
⁴ College of Chemistry, Chemical Engineering and Environmental Engineering, Liaoning Shihua University, Fushun 113001, China.

Abstract

In this study, hollow square rodlike microtubes composed of anatase nanocuboids with coexposed {100}, {010}, and {001} facets were successfully synthesized via a mild hydrothermal treatment method in the presence of NH₄F by using layered H₂Ti₃O₇ ribbons as the precursor. The precursor H₂Ti₃O₇ ribbons were prepared from H⁺/Na⁺ ion-exchanged Na₂Ti₃O₇. The suspension solution of protonated H₂Ti₃O₇ ribbons was adjusted to desired pH values (0.5-13.0) prior to hydrothermal treatment. The elongated direction of the microtubes is along the b axis, according to the profile of the H₂Ti₃O₇ ribbons. The transformation from staggered [Ti₃O₇]^2- sheets to hollow square rodlike microtubes contained the formation and recombination of the dispersed octahedral [Ti(OH)₂(OH₂)₄]²⁺ monomers, the formation and growth of the initial anatase nuclei, and the reassembly of the anatase nanocuboids along the b-axis direction during the continuous hydrothermal process. The degradation rate of pH 0.5-TiO₂ was the highest at 1.66 × 10^-2 min^-1, which was 1.3, 1.5, 2.0, 2.3, and 18.4 folds higher than that of pH 3.0-TiO₂ (1.27 × 10^-2 min^-1), pH 7.0-TiO₂ (1.11 × 10^-2 min^-1), pH 5.0-TiO₂ (0.83 × 10^-2 min^-1), P25-TiO₂ (0.73 × 10^-2 min^-1), and the blank sample (0.09 × 10^-2 min^-1), respectively. Compared with P25-TiO₂ and the other anatase TiO₂ samples, pH 0.5-TiO₂ exhibited the best photocatalytic activity, which was mainly attributed to its larger proportion of {010} (or {100}) facets, smaller crystalline size, higher band gap, and larger specific surface area.