In‐situ Photosynthetic Route to Tailor Point Defects in TiO₂(B) Nanosheets for Visible Light‐Driven Photocatalytic Hydrogen Production

Abstract

In‐situ UV‐irradiation activation leads to an intense visible‐light absorption of up to 700 nm in ethylene glycolate‐stabilized TiO2(B) nanosheets. It is ascribed that the creation of abundant subsurface/lattice oxygen vacancies and Ti3+ centers, along with UV‐induced breakdown of Ti−O bonds between ethylene glycolate and TiO2(B). Consequently, the enhanced and stable visible‐light‐driven photocatalytic H2 evolution is obtained on defect‐rich TiO2(B) nanosheets.

Facile and Large-scale Synthesis of Defective Black TiO2−x(B) Nanosheets for Efficient Visible-light-driven Photocatalytic Hydrogen Evolution

“…More interesting, the amount of lattice Ti-O-Ti bonds relative to surface Ti-O-H bonds/O-defective matrix was notably increased in BT3, as compared to those of BT. The results indicate the simultaneous production of oxygen vacancy sites [26,32].…”

“…As represented in Figure 5c, the deconvoluted peaks of O1s at 529.7, 531.0, and 532.8 eV are due to the lattice oxygen (Ti-O-Ti), surface hydroxyl group/O-defective matrix (Ti-O-H), and Ti-O-C groups, respectively [30][31][32]. The observation of Ti-O-C groups can be attributed to the surface-absorbed ethylene glycolate [26]. More interesting, the amount of lattice Ti-O-Ti bonds relative to surface Ti-O-H bonds/O-defective matrix was notably increased in BT3, as compared to those of BT.…”

“…The synthesis process is facile with ethylene glycol solutions and 140-180 • C, and only involves a one-step hydrolysis reaction of TiCl 3 or TiCl 4 [23,24]. Therefore, extensive efforts have been contributed to investigate the applications of the TiO 2 (B) nanosheet in the photocatalysis field [23,[25][26][27][28]. However, due to the metastable structure and character of TiO 2 (B), almost no work has been reported on the facile and large-scale synthesis method and concurrently controllable structure and optical properties for defect-rich TiO 2−x (B).…”

Flower-like hydrogen titanate nanosheets: preparation, characterization and their photocatalytic hydrogen production performance in the presence of Pt cocatalyst

“…Among them, TiO 2 acted as the most extensively used catalyst for photocatalysis owing to its good photocatalytic activity, high stability, non-toxicity and lowcost. [7][8][9][10][11][12][13] However, the photocatalytic activity for H 2 production over TiO 2 is very low, mainly due to the rapid recombination of photogenerated electrons and holes. 14 So there are several ways to overcome these shortcomings and greatly enhance photocatalytic H 2 production activity, such as dye sensitization, 15 semiconductor composite 16 and cocatalyst modication.…”

Design of Organic-Free Superhydrophobic TiO2 with Ultraviolet Stability or Ultraviolet-Induced Switchable Wettability

“…Generally, photogenerated electrons and holes were produced when TiO 2 was under UV light irradiation; thus, the carriers migrated to the surface of TiO 2 and then reacted with the lattice oxygen of TiO 2 , which broke the Ti-O bond to produce oxygen vacancies. 42,43 Because of the hydrogen bonding interaction between oxygen vacancies and water molecules, a large amount of water was rapidly adsorbed onto the oxygen vacancies, resulting in the loss of the superhydrophobic properties of TiO 2 . 42,44 Therefore, core/ shell TiO 2 /TiO 2 −3 exhibited superhydrophilicity under UV light irradiation.…”