Plasma Treating Mixed Metal Oxides to Improve Oxidative Performance via
Defect Generation.
MATERIALS 2019;
12:ma12172756. [PMID:
31462008 PMCID:
PMC6747793 DOI:
10.3390/ma12172756]
[Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 08/23/2019] [Accepted: 08/26/2019] [Indexed: 12/02/2022]
Abstract
The generation of structural defects in metal oxide catalysts offers a potential pathway to improve performance. Herein, we investigated the effect of thermal hydrogenation and low-temperature plasma treatments on mixed SiO2/TiO2 materials. Hydrogenation at 500 °C resulted in the reduction of the material to produce Ti3+ in the bulk TiO2. In contrast, low temperature plasma treatment for 10 or 20 min generated surface Ti3+ species via the removal of oxygen on both the neat and hydrogenated material. Assessing the photocatalytic activity of the materials demonstrated a 40–130% increase in the rate of formic acid oxidation after plasma treatment. A strong relationship between the Ti3+ content and catalyst activity was established, although a change in the Si–Ti interaction after plasma treating of the neat SiO2/TiO2 material was found to limit performance, and suggests that performance is not determined solely by the presence of Ti3+.
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