<i>In situ</i> growth of porous TiO₂ with controllable oxygen vacancies on an atomic scale for highly efficient photocatalytic water splitting

In situ regulation of oxygen vacancies of porous TiO2 at atomic scale with promoting photocatalytic efficiency.</p

Enhancement of Titania Photoanode Performance by Sandwiching Copper between Two Titania Layers

Vacancies in semiconductors can play a versatile role in boosting their photocatalytic activity. In this work, a novel TiO2/Cu/TiO2 sandwich structure is designed and constructed. Abundant vacancies were introduced in TiO2 lattice by Cu reduction under heat treatment. Meanwhile, Cu atom could diffuse into TiO2 to form Cu-doped TiO2. The synergistic effect between oxygen vacancies and Cu atoms achieved about 2.4 times improved photocurrent of TiO2/Cu/TiO2 sandwich structure compared to bare TiO2 thin film. The enhanced photoactivity may be attributed to regulated electron structure of TiO2 by oxygen vacancies and Cu dopant from experimental results and density functional theory calculations. Oxygen vacancies and Cu dopant in TiO2 formed through copper metal reduction can introduce impurity levels and narrow the band gap of TiO2, thus improve the visible light response. More importantly, the Cu2+ and oxygen vacancies in TiO2 lattice can dramatically increase the charge density around conduction band and promote separation of photo-induced charge carriers. Furthermore, the oxygen vacancies on the surface may serve as active site for sufficient chemical reaction. This work presents a novel method to prepare doped metal oxides catalysts with abundant vacancies for improving photocatalytic activity.</jats:p

Improved atomic layer deposition method enhances the unit catalytic activity of platinum catalyst in oxygen reduction reaction

The construction of uniformly dispersed and low-loading platinum-containing catalysts is a challenging task to promote the oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells (PEMFCs) using highly efficient and relatively low-cost catalysts. Here, we propose a strategy to prepare active Pt catalysts with cluster structures by a simplified atomic layer deposition (ALD) method that does not require the incorporation of equipment such as a fluidized bed reactor to control the distribution of carriers in the reaction chamber. Unlike the conventional ALD methods, the deposition of precious metal Pt on carbon aerogel (CA) does not require O3 or O2 to participate in all reactions, and the platinum content is directly controlled by the ALD cycle method, and a series of Pt@CA materials have successfully synthesized catalysts with different platinum content by adjusting the pulse time, purge time and cycle times. Compared with commercial platinum carbon catalysts, these Pt@CA catalysts synthesized by the simplified ALD method have higher electrochemical active surface area (ECSA) and unit mass activity (MA) due to their excellent uniformity, dispersion, and high utilization of Pt active sites. This study, which focuses on atomic-scale strategies for Pt-containing materials, marks a step towards modern high-performance catalysts for future fuel cell technologies

Enhancement of Titania Photoanode Performance by Sandwiching Copper between Two Titania Layers

Vacancies in semiconductors can play a versatile role in boosting their photocatalytic activity. In this work, a novel TiO2/Cu/TiO2 sandwich structure is designed and constructed. Abundant vacancies were introduced in TiO2 lattice by Cu reduction under heat treatment. Meanwhile, Cu atom could diffuse into TiO2 to form Cu-doped TiO2. The synergistic effect between oxygen vacancies and Cu atoms achieved about 2.4 times improved photocurrent of TiO2/Cu/TiO2 sandwich structure compared to bare TiO2 thin film. The enhanced photoactivity may be attributed to regulated electron structure of TiO2 by oxygen vacancies and Cu dopant from experimental results and density functional theory calculations. Oxygen vacancies and Cu dopant in TiO2 formed through copper metal reduction can introduce impurity levels and narrow the band gap of TiO2, thus improve the visible light response. More importantly, the Cu2+ and oxygen vacancies in TiO2 lattice can dramatically increase the charge density around conduction band and promote separation of photo-induced charge carriers. Furthermore, the oxygen vacancies on the surface may serve as active site for sufficient chemical reaction. This work presents a novel method to prepare doped metal oxides catalysts with abundant vacancies for improving photocatalytic activity

Synthesis and characterization of cellulose triacetate aerogels with ultralow densities

A novel method that needs only dissolution, gelation and ScCO2drying has been developed to fabricate ultralow density, nanostructured TAC aerogels.</p