scholarly journals Photocatalytic Reduction of Hexavalent Chromium with Nanosized TiO2 in Presence of Formic Acid

2019 ◽  
Vol 3 (2) ◽  
pp. 33 ◽  
Author(s):  
Jahida Binte Islam ◽  
Mai Furukawa ◽  
Ikki Tateishi ◽  
Hideyuki Katsumata ◽  
Satoshi Kaneco
Keyword(s):  
Titanium Dioxide ◽  
Formic Acid ◽  
Tio2 Nanoparticles ◽  
Hexavalent Chromium ◽  
Oxidation Reaction ◽  
Photocatalytic Reduction ◽  
Nanosized Titanium Dioxide ◽  
Hole Scavenger ◽  
Nanosized Tio2 ◽  
Commercial Tio2

Nanosized titanium dioxide (TiO2) nanoparticles were used for the photocatalytic reduction of hexavalent chromium in the presence of formic acid. The photoreduction of Cr(VI) in the absence of formic acid was quite slow. When formic acid was added in the chromium solution as the hole scavenger, a rapid photocatalytic reduction of Cr(VI) was observed, owing to the consumption of hole and the acceleration of the oxidation reaction. Furthermore, three commercial TiO2 nanoparticles (AEROXIDE® P25; Ishihara Sangyo ST-01; FUJIFILM Wako Pure Chemical Corp.) were evaluated for the photoactivity of reduction of Cr(VI).

scholarly journals Impacts of Mixing Mode on Photocatalytic Reduction of Hexavalent Chromium over Titanium Dioxide Nanomaterial under Various Environmental Conditions

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2291
Author(s):  
Chih-Chi Yang ◽  
Khanh-Chau Dao ◽  
Yo-Sheng Lin ◽  
Teng-Yun Cheng ◽  
Ku-Fan Chen ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Hexavalent Chromium ◽  
Species Distribution ◽  
Uv Light ◽  
Photocatalytic Reduction ◽  
Oxygen Effect ◽  
Strong Interactions ◽  
Nitrogen Gas ◽  
Key Factor ◽  
Hole Scavenger

This study explores the effects of initial Cr(VI) concentration, wavelength, hole-scavenger (absence and presence of salicylic acid), and oxygen conditions (aeration by air, nitrogen gas, and mechanical stir only) on photocatalytic reduction of hexavalent chromium over titanium dioxide photocatalyst and the chromic species distribution after photocatalysis. The experimental results show the existence of strong interactions between these factors. The factor of hole-scavenger was more important than the UV light wavelength condition for a reduction of 3 mg Cr(VI) L−1, whereas both factors became important when Cr(VI) concentration increased to 20 mgL−1. The higher the UV wavelength was, the less the amount of chromium retained on the TiO2 surface. The influence of oxygen-containing conditions in the solution on the reduction of 3 mgL−1 Cr(VI) was unobvious, whereas its influence became remarkable for the reduction of 20 mgL−1 Cr(VI) in the presence of SA. The interaction between oxygen-containing factor and other environmental factors, such as Cr(VI) concentration and scavenger presence (SA in this study), is a key factor about the degree of oxygen effect on Cr(VI) photo-reduction and the chromic species distribution. Simple stirring obtained better photocatalytic efficiency than aeration by air or nitrogen gas.

Photocatalytic reduction behavior of hexavalent chromium on hydroxyl modified titanium dioxide

2017 ◽  
Vol 206 ◽  
pp. 293-299 ◽  
Author(s):  
Yali Li ◽  
Yingying Bian ◽  
Hongxia Qin ◽  
Yaxi Zhang ◽  
Zhenfeng Bian
Keyword(s):  
Titanium Dioxide ◽  
Hexavalent Chromium ◽  
Photocatalytic Reduction ◽  
Reduction Behavior

Photocatalytic reduction of Cr(VI) in aqueous solution using TiO2 nanoparticles prepared with various alcohols as solvent

2012 ◽  
Vol 66 (6) ◽  
pp. 1333-1339 ◽  
Author(s):  
Young Ku ◽  
Chia–Nan Lin ◽  
Wei–Ming Hou
Keyword(s):  
Phase Transformation ◽  
Tio2 Nanoparticles ◽  
Surface Area ◽  
Hexavalent Chromium ◽  
Sol Gel ◽  
Photocatalytic Reduction ◽  
Structure Characterization ◽  
Phase Transformation Temperature ◽  
Reduction Activity ◽  
Sol Gel Process

TiO2 nanoparticles were prepared with various linear alkyl chains of alcohols under a sol–gel process. The structure characterization and the photocatalytic reduction of hexavalent chromium of the TiO2 nanoparticles were investigated. The phase transformation temperature, crystal aggregation and surface area of prepared TiO2 samples were found to be strongly influenced by alcohol used. The phase transformation from anatase to rutile was retarded and the surface area was reduced for TiO2 prepared with alcohols of longer alkyl chain. TiO2 nanoparticles prepared with methanol or ethanol exhibited higher photocatalytic reduction activity of hexavalent chromium possibly due to greater and more positively charged surface area.

Enhanced photocatalytic reduction of aqueous Pb(II) over Ag loaded TiO2with formic acid as hole scavenger

2012 ◽  
Vol 47 (3) ◽  
pp. 327-336 ◽  
Author(s):  
Liyuan Li ◽  
Fang Jiang ◽  
Jingliang Liu ◽  
Haiqin Wan ◽  
Yuqiu Wan ◽  
...  
Keyword(s):  
Formic Acid ◽  
Photocatalytic Reduction ◽  
Hole Scavenger

scholarly journals Enhanced Solar Photocatalytic Reduction of Hexavalent Chromium in Seawater over Carbon Doped TiO2 Nanoparticles

2018 ◽  
Vol 28 (2) ◽  
pp. 17-26
Author(s):  
Yasser A. Shaban Yasser A. Shaban
Keyword(s):  
Hexavalent Chromium ◽  
Removal Rate ◽  
Reduction Rate ◽  
Pure Tio2 ◽  
Photocatalytic Reduction ◽  
Experimental Conditions ◽  
Carbon Doped ◽  
First Order Kinetics ◽  
Photocatalytic Removal ◽  
Hole Scavenger

The photocatalytic removal of hexavalent chromium Cr(VI) from polluted seawater has been successfully investigated by using carbon doped titanium oxide (CTiO2 ) nanoparticles under irradiation of natural sunlight. The photoactivity of CTiO2 was comparatively evaluated with pure TiO2 under the same experimental conditions. The effects of catalyst dose, initial Cr(VI) concentration and pH were studied and optimized. The highest removal rate was obtained at pH 3 and catalyst dose of 2.0 g L-1 . Furthermore, the existence of hole scavenger remarkably enhanced the reduction rate of Cr(VI). According to Langmuir–Hinshelwood model, the photocatalytic reduction of Cr(VI) using CTiO2 obeyed the pseudo-first-order kinetics

Sign in / Sign up

Export Citation Format

Share Document