Carbon-doped titania nanoplates with exposed {001} facets: facile synthesis, characterization and visible-light photocatalytic performance

Abstract

C-doped TiO 2 nanoplates (CTNP) with exposed {001} facets were successfully synthesized by hydrothermal treatment of TiC powder in a HF-HNO 3 mixed aqueous solution for the first time. The effects of hydrothermal temperature (140, 160, 180 and 200 o C) on the crystal phase, morphology, specific surface area and porous property, surface element composition, optical response property of the 10 resultant samples were investigated in detail, and the photocatalytic activities of these obtained CTNP samples for the degradation of methylene blue (MB) were evaluated under visible light irradiation. The results showed that precursor cubic TiC was transformed into anatase TiO 2 with the morphology of welldefined nanoplate completely after hydrothermal treatment 30 h. The specific surface area of CTNP was significantly improved in comparison with that of micrometer sized C-doped TiO 2 plates (CTP) due to 15 smaller particle size. Due to C-doping, CTNP presented red-shift absorption edge, which supported it with strong visible-light response. All these factors led to as-prepared CTNP having more excellent visible-light photocatalytic activity in comparison with micrometer sized CTP. The CTNP synthesized at 180 o C presented the optimal visible-light photocatalytic activity with a high reaction rate constant (0.03692 min −1 ) among the four CTNP samples. Based on the results of the present study, a reasonable 20 mechanism of photocatalysis on CTNP under visible light was proposed.

Influences of Doping on Photocatalytic Properties of TiO2 Photocatalyst

“…Subsequently, a lot of researches were conducted to synthesize C-doped TiO 2 photocatalysts [120][121][122][123][124]. Shi et al prepared nanometer-sized C-doped TiO 2 nanoplates with exposed {001} facets via the hydrothermal treatment of TiC powder in an HF-HNO 3 mixed aqueous solution and found that C doping also obviously presented red shift absorption edge towards visible light [120]. Further analysis found that the electrons in the localized C states could be excited to the CB under visible light irradiation and effectively scavenged by molecular O to produce the superoxide radical anion (•O 2 -) and hydrogen peroxide (H 2 O 2 ), which could interact to produce hydroxyl radicals (•OH).…”

Nitrogen Doped Titania Plates with Dominant {001} Facets: The Effect of Surface Fluorination on Visible-Light Photocatalytic Activity

“…Hydroxyl radical is a very important species produced in the process of photocatalysis, which is responsible for the decomposition of organic pollutant. In order to test the effect of hydrothermal treatment and following calcination on the generated amount of •OH radicals, the amount of •OH generated during photocatalysis of sample S20 and S20-air were measured according to the literature [3]. As shown in Fig.…”

“…Owing to the high photocatalytic activity and the ability to utilize visible light, nonmetal doped TiO 2 crystals (e.g. N, C, S, F) with exposed {001} facets have attracted considerable attention in the recent years [2][3][4][5]. In our recent work [6], we successfully prepared N-doped anatase TiO 2 plates with dominated {001} facets (abbr.…”

Photocatalysis and Li-Ion Battery Applications of {001} Faceted Anatase TiO2-Based Composites

“…Non-metal ion doping: For non-metal doping in TiO 2 in anionic sites (oxygen), wide varieties of anionic species N [68], S [69], C [70], or F [71] have been used. This approach consists of the substitution of a non-metal atom for an oxygen atom in TiO 2 .…”