Effect of metal and non-metal doping on photocatalytic performance of titanium dioxide (TiO2): A Review

2021 ◽  
Vol 17 ◽  
Author(s):  
Abdullah Aljaafari
Keyword(s):  
Titanium Dioxide ◽  
Environmental Sustainability ◽  
Uv Light ◽  
Synthesis Methods ◽  
Fossil Fuel Combustion ◽  
Characterization Methods ◽  
Energy Demands ◽  
Photocatalytic Reactions ◽  
Visible Light Activation ◽  
Preparation Techniques

: Titanium dioxide (TiO2) is a known semiconducting material that has been effectively used in photo-catalytic processes to promote environmental sustainability. It can also reduce the environmental chaos caused by fossil fuel combustion to meet energy demands. Many studies have proposed modifications of the large band gap in TiO2, which causes visible light activation during photocatalytic reactions when exposed to UV light radiation. Therefore, many alterations such as the doping of nonmetals and metals to TiO2 have been investigated. In this review, we discuss advanced preparation techniques for TiO2 with various dopants and techniques. Characterization methods were performed to evaluate the structural, morphological, and optical properties of TiO2 doped with metal and nonmetal ions such as S, C, N, Fe, B, W, Ag, Nb, and Zn by various synthesis methods. We have also explored the experimental and other characteristics to determine the best doping component for use in real-time applications.

scholarly journals A Mini Review on Bismuth-Based Z-Scheme Photocatalysts

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5057
Author(s):  
Ruizhen Li ◽  
Hanyang Chen ◽  
Jianrong Xiong ◽  
Xiaoying Xu ◽  
Jiajia Cheng ◽  
...  
Keyword(s):  
Environmental Pollutants ◽  
Co2 Reduction ◽  
Pollutant Removal ◽  
Energy Utilization ◽  
Research Progress ◽  
Future Perspective ◽  
Synthesis Methods ◽  
Pollutants Removal ◽  
Photocatalytic Reactions ◽  
Redox Ability

Recently, the bismuth-based (Bi-based) Z-scheme photocatalysts have been paid great attention due to their good solar energy utilization capacity, the high separation rate of their photogenerated hole-electron pairs, and strong redox ability. They are considerably more promising materials than single semiconductors for alleviating the energy crisis and environmental deterioration by efficiently utilizing sunlight to motivate various photocatalytic reactions for energy production and pollutant removal. In this review, the traits and recent research progress of Bi-based semiconductors and recent achievements in the synthesis methods of Bi-based direct Z-scheme heterojunction photocatalysts are explored. The recent photocatalytic applications development of Bi-based Z-scheme heterojunction photocatalysts in environmental pollutants removal and detection, water splitting, CO2 reduction, and air (NOx) purification are also described concisely. The challenges and future perspective in the studies of Bi-based Z-scheme heterojunction photocatalysts are discussed and summarized in the conclusion of this mini review.

Carbon-modified TiO2 as Photocatalysts

2010 ◽  
Vol 13 (3) ◽  
Author(s):  
Magdalena Janus ◽  
Antoni W. Morawski
Keyword(s):  
Carbon Dioxide ◽  
Titanium Dioxide ◽  
Advanced Oxidation Processes ◽  
Uv Light ◽  
Pure Titanium ◽  
Light Irradiation ◽  
Oxidation Processes ◽  
Uv Light Irradiation ◽  
Ultraviolet Light Irradiation ◽  
Long Time

AbstractPhotocatalysis belongs to one of the Advanced Oxidation Processes (AOP). These processes make possible the decomposition of organic compounds to carbon dioxide and water. The most useful photocatalyst is titanium dioxide which, to make it active, requires irradiation with suitable wavelengths. Pure titanium dioxide can be activated only by ultraviolet light irradiation (UV). For a long time, studies have been carried on modified titanium dioxide materials to obtain more effective photocatalysts with greater activity under UV light irradiation or to obtain photocatalysts which may be active also under visible light irradiation. One of the possible ways for modifying TiO

scholarly journals The Complex Compound of Amino Acids With Titanium (III) as a Method to Control and Synthesis of Different Structures of TiO2 Nanoparticles; Usage as Photocatalysts to Oxidize Alcohols to Aldehyde

2021 ◽  
Author(s):  
Yahya Absalan ◽  
Nazanin Noroozi Shad ◽  
Mostafa Gholizadeh
Keyword(s):  
Amino Acids ◽  
Titanium Dioxide ◽  
Uv Light ◽  
Chemical Analyses ◽  
Benzyl Alcohols ◽  
Titanium Dioxide Nanoparticle ◽  
Physical Chemical ◽  
Nitrobenzyl Alcohol ◽  
Different Types ◽  
Full Investigation

Abstract Different types of the amino acids (Glutamine, Glycine, Alanine) were used to coordinate TiCl3 in order to investigating the best precursor for synthesis of TiO2. Also, a full investigation was carried out to synthesis four different structures of TiO2 nanoparticles [TiO2 (A0.8R0.2), TiO2 (A0.6R0.4), TiO2 (Anatase), and TiO2 (Rutile)]. Oxidation of derivatives alcohol to their corresponding aldehyde through the obtained nanoparticles, as a photocatalyst, under UV light was considered to investigate the best structure of TiO2. Different physical-chemical analyses were applied to investigate the result. The result showed that the titanium dioxide nanoparticle, synthesized from glycine was obtained at the least temperature and was chosen as a precursor to synthesis of four different types of TiO2. All the synthesized TiO2 were applied for oxidation of benzyl alcohols into benzaldehyde, as a test, and TiO2 (A0.6R0.4) could give the best result (87% efficiency). Then it was used to oxidize benzyl alcohol, 4-cholorobenzyl alcohol, 4-nitrobenzyl alcohol and 4-methoxybenzyl alcohol to their corresponding aldehyde and efficiency were 74, 92, 87, and 65% respectively.

scholarly journals A Study on the Photocatalytic Reduction of Some Metal Ions in Aqueous Solution Using UV- Titanium Dioxide System

2019 ◽  
pp. 1-7
Author(s):  
I. O. Ekwere ◽  
M. Horsfall ◽  
J. O. E. Otaigbe
Keyword(s):  
Aqueous Solution ◽  
Titanium Dioxide ◽  
Metal Ions ◽  
Metal Ion ◽  
Uv Light ◽  
Kinetic Studies ◽  
Photocatalytic Reduction ◽  
Alkaline Ph ◽  
Removal Of Metal ◽  
Removal Of Metal Ions

The photocatalytic reduction of Cu (II), Pb (II), Cd (II) and Cr (VI) ions in aqueous solution has been investigated. The photocatalyst utilized was nano titanium dioxide, composed of 80% anatase and 20% rutile; the UV light source was a 15 W UV bulb with a wavelength of 254 nm. The results obtained indicated a reduction efficiency order as follows; Cr6+ > Cu2+ > Pb2+ > Cd2+. It was observed that these results correlate with the respective reduction potentials of the metal ions. The effect of pH on the photocatalytic reduction of the metal ions was also carried out and results obtained indicated that with the exception of Cr (VI) ions, higher percentage removal of metal ions from their aqueous solution was recorded at alkaline pH than at acidic pH. This was attributed to an extensive formation of precipitate by the metal ions at alkaline pH. Kinetic studies revealed that the removal of metal ions from their solutions largely followed the pseudo- first-order kinetics. Therefore, the results of this study will be useful in metal ion removal from industrial waste water using photocatalytic process.

scholarly journals Ag(I)/TiO2-Photocatalyzed N-Methylation of Amino Acids with Methanol

2020 ◽  
Author(s):  
Yuna Morioka ◽  
Ivven Huang ◽  
Susumu Saito ◽  
Hiroshi Naka
Keyword(s):  
Amino Acids ◽  
Titanium Dioxide ◽  
Uv Light ◽  
Optical Purity

<div><div><div><p>Silver(I)-loaded titanium dioxide (AgNO3/TiO2) catalyzes the direct N-methylation of amino acids with methanol under irradiation with UV light. This method produces a variety of N-methyl and N,N-dimethyl amino acids with retention of their optical purity.</p></div></div></div>

scholarly journals Preparation of Titanium Dioxide Nanoparticles Immobilized on Polyacrylonitrile Nanofibres for the Photodegradation of Methyl Orange

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Pardon Nyamukamba ◽  
Omobola Okoh ◽  
Lilian Tichagwa ◽  
Corinne Greyling
Keyword(s):  
Electron Microscopy ◽  
Titanium Dioxide ◽  
Methyl Orange ◽  
Organic Contaminants ◽  
Uv Light ◽  
Titanium Dioxide Nanoparticles ◽  
Xrd Analysis ◽  
Rutile Phase ◽  
Electrospinning Technique ◽  
Carbon Nanofibres

Herein, we describe the synthesis of titanium dioxide (TiO2) nanoparticles by the hydrolysis and condensation of titanium tetrachloride. The resulting nanoparticles were immobilized on polyacrylonitrile (PAN) based nanofibres by an electrospinning technique in order to allow simple isolation and reuse of titania semiconductor photocatalyst. The composite nanofibres were heat treated to convert the polymer nanofibres to carbon nanofibres and to convert amorphous TiO2to crystalline TiO2. X-ray diffraction (XRD) analysis showed that the rutile phase was the major phase and the equatorial peaks of PAN disappeared after heat treatment at 600°C. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analysis confirmed that some TiO2nanoparticles were encapsulated whereas some were surface residing on the electrospun nanofibres. The TiO2nanoparticles were found to lower the cyclization temperature of PAN as indicated by differential scanning colorimetry (DSC) and differential thermal analysis (DTA). Photocatalytic studies on the degradation of methyl orange dye under UV light irradiation showed that composite nanofibres were capable of degrading organic contaminants in water. The carbon nanofibres with surface residing titanium dioxide nanoparticles (TiO2/CNF-SR) showed the highest photocatalytic activity (59.35% after 210 minutes) due to direct contact between the TiO2photocatalyst and methyl orange.

scholarly journals Photo-catalytic degradation of polyphenolic tannins in continuous-flow reactor using titanium dioxide immobilized on a cellulosic material

2020 ◽  
Vol 82 (7) ◽  
pp. 1454-1466
Author(s):  
Abdelhadi Jouali ◽  
Anas Salhi ◽  
Abdelkahhar Aguedach ◽  
El Kbir Lhadi ◽  
Mohammed El Krati ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Continuous Flow ◽  
Flow Reactor ◽  
Uv Light ◽  
Catalytic Degradation ◽  
Light Irradiation ◽  
Maximum Efficiency ◽  
Environmental Damage ◽  
Continuous Flow Reactor ◽  
Uv Light Irradiation

Abstract Tannins are recalcitrant polyphenolic molecules that resist microbial attack. Their main environmental damage is due to their low biodegradability. This work aims to investigate the photo-catalytic degradation of two commercial tannin extracts, chestnut (hydrolysable tannin) and mimosa (condensed tannin). The experiments were carried out under UV-light irradiation in a continuous-flow reactor using titanium dioxide (TiO2) immobilized on cellulosic fibers. It was highlighted that photo-catalytic degradation is unfavourable in acidic medium and when the pH is too high (pH above 12); it reaches its maximum efficiency at pH 7.5 (99 and 97% for chestnut and mimosa, respectively). Nearly complete degradation of tannins requires an irradiation period of 6 h. The process efficiency is inversely affected by the concentration of tannins essentially above 75 mg/L for chestnut and 60 mg/L for mimosa. Above 240 mL/min, any increase in feed flow negatively affects the performance of the process. Furthermore, a significant decrease of treatment efficiency was seen when increasing the concentration of ethanol and salts in the medium. Obtained results suggest that UV-light irradiation in a continuous-flow photo-reactor using immobilized TiO2 may be considered as an adequate process for the treatment of water containing recalcitrant tannin molecules.

Sign in / Sign up

Export Citation Format

Share Document