Titanium Vacancies in TiO₂ Nanofibers Enable Highly Efficient Photodriven Seawater Splitting

Abstract

Photodriven seawater splitting is considered to be one of the most promising techniques for sustainable hydrogen production. However, the high salinity of seawater would deactivate catalysts and consume the photogenerated carriers. Metal vacancies in metal oxide semiconductors are critical to directed electron transfer and high salinity resistance; they are thus desirable but remain a challenge. We demonstrate a facile controllable calcination approach to synthesize TiO 2 nanofibers with rich Ti vacancies with excellent photo/electro performances and long-time stability in photodriven seawater splitting, including photocatalysis and photo-electrocatalysis. Experimental measurements and theoretical calculations reveal the formation of titanium vacancies, as well as unidirectional electron trap and superior H + adsorption ability for efficient charge transfer and resistance to corrosion by seawater. Therefore, atomic-/nanoscale characteristics and mechanism have been proposed to clarify the generation of titanium vacancies and the corresponding interfacial electron transfer.

A spatial homojunction of titanium vacancies decorated with oxygen vacancies in TiO2 and its directed charge transfer

“…36 After compositing, a superposition of the signals is observed in np-TiO 2 at a high magnetic field, which is due to the existence of titanium vacancies. 37,38 The EPR spectra indicate the co-existence of Ti-vacancies and O-vacancies in np-TiO 2 .…”

A Semiconductor Biohybrid System for Photo‐Synergetic Enhancement of Biological Hydrogen Production

“…[8] Fragility of microorgan-isms and toxicity of semiconductor materials make this system unstable, which is the bottleneck problem. [9] Nowadays, hydrogen production from seawater has aroused widespread interest, [10] in which the high salinity can lead to cell inactivation. Therefore, cytoprotective strategies need to be implemented to enable long-term stability even in high salinity environment.…”

A RuCoBO Nanocomposite for Highly Efficient and Stable Electrocatalytic Seawater Splitting

“…Furthermore, compared to the surface of a pure alloy, the one in the calcinated nanocomposites with more oxidized surface species should have favorable hydrophilicity (Figures S11 and S12 and detailed description). High hydrophilicity is a desirable property for seawater-splitting catalysts, which leads to accelerated water-adsorption/dissociation that improves performance and ion shielding that enhances stability. , …”

“…High hydrophilicity is a desirable property for seawater-splitting catalysts, which leads to accelerated water-adsorption/dissociation that improves performance and ion shielding that enhances stability. 38,39 The HER and OER activities and stabilities of Ru S5). Also, Ru 2 Co 1 BO-350 displays the largest electrochemical doublelayer capacitance (C dl ) (43.3 mF cm −2 ), indicating that it possesses a greatly enhanced number of surface active sites (Figures 3d and S18).…”