Visible light-driven enhanced CO2 reduction by water over Cu modified S-doped g-C3N4

2019 ◽  
Vol 9 (17) ◽  
pp. 4598-4613 ◽  
Author(s):  
Niwesh Ojha ◽  
Abhinav Bajpai ◽  
Sushant Kumar
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Co2 Reduction ◽  
Impregnation Method ◽  
Thin Sheets ◽  
Wet Impregnation ◽  
Visible Light Driven ◽  
Plausible Mechanism ◽  
Wet Impregnation Method

We synthesized Cu modified S-doped g-C3N4 thin sheets using calcination followed by a wet-impregnation method. The photocatalytic activity was studied for reduction of CO2 to CO and CH4 in the presence of water and a plausible mechanism is explained.

scholarly journals Effect of Different Calcination Temperatures on the Structural and Photocatalytic Performance of Bi-TiO2/SBA-15

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Jing Ma ◽  
Jia Chu ◽  
Liangsheng Qiang ◽  
Juanqin Xue
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Performance ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Calcination Temperatures ◽  
New Novel ◽  
Vis Spectroscopy ◽  
Novel Material ◽  
Adsorption Desorption

The new novel material Bi-TiO2/SBA-15 was synthesized by an easy wet impregnation method. A combination of XRD, XPS, Raman, N2adsorption-desorption isotherm measurement, TEM, and solid state UV-Vis spectroscopy has been used to characterize the Bi-TiO2/SBA-15 material. It was found that SBA-15 retained the ordered hexagonal mesostructure after incorporation of TiO2and Bi. The photodecomposition of rhodamine B (RhB) in aqueous medium was selected to evaluate the photocatalytic performance of Bi-TiO2/SBA-15 under visible light irradiation (λ≥420 nm). The experiment results indicated that Bi-TiO2/SBA-15 exhibited higher photocatalytic activities than pure TiO2and Bi2O3. The influences of calcination temperature were studied. It strongly influenced the activity of the samples. The sample calcined at 550°C shows the highest photocatalytic activity in the decomposition of RhB under visible light. The catalyst preserved almost its initial photocatalytic activity after six reuses.

scholarly journals Copper modified TiO2 and g-C3N4 catalysts for photoreduction of CO2 to methanol using different reaction mediums

2015 ◽  
Vol 11 (3) ◽  
Author(s):  
Adekoya Oluwatobi David ◽  
Muhammad Tahir ◽  
Nor Aishah Saidina Amin
Keyword(s):  
Co2 Reduction ◽  
Reaction Medium ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Co2 Photoreduction ◽  
Hole Scavenger ◽  
Naoh Solution ◽  
Uv Lamp ◽  
Methanol Economy ◽  
Wet Impregnation Method

In this study, Cu/TiO2 and Cu/g-C3N4 catalysts were tested for CO2 reduction to methanol. The catalysts were prepared by the wet impregnation method and, characterized by XRD and FESEM. The product identification and yield were determined using a GC with FID. The CO2 photoreduction process was performed in each of the following reaction mediums: H2O, NaOH, KOH, Na2CO3, K2CO3, NaHCO3 and KHCO3. The efficiency was studied by comparing the methanol yield for each. A slurry type photoreactor with a UV lamp of 365 nm wavelength was used. CO2 photoreduction to methanol using NaOH as the reaction medium registered the highest yield of 431.65 μmole/g-cat•hr. This is due to the higher solubility of CO2 in the alkali as compared to that of the other reaction mediums, the ability of NaOH to serve as a hole scavenger owing to the formation of OH•ions and the higher selectivity of NaOH solution for CO2 photoreduction to methanol. It was obvious the choice of reaction medium affected the photoreduction of CO2 to methanol. The trend of results indicated the use of NaOH as a reaction medium improved the efficiency of the photoreduction process. The findings from this research could promote research in the field of photocatalysis by improving the yield which will encourage the support for methanol economy. 

scholarly journals Mesoporous Ce-doped Ti:Ash Photocatalyst Investigation in Visible Light Photocatalytic Water Pretreatment Process

2020 ◽  
Vol 15 (2) ◽  
pp. 367-378
Author(s):  
Abdulkarim Abdulrahman Mohamed Suliman ◽  
Ruzinah Isha ◽  
Mazrul Nizam Abu Seman ◽  
Abdul Latif Ahmad ◽  
Jamil Roslan
Keyword(s):  
Visible Light ◽  
Visible Region ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
X Ray ◽  
Weight Percentage ◽  
Water Pretreatment ◽  
Defect Sites ◽  
Adsorption Desorption ◽  
Wet Impregnation Method

The treatment of organic pollutants in water including semiconductor photocatalysis is a promising approach to disinfect water. The objective of this study is to investigate the effect of Ce loaded on mesoporous Ti:Ash catalyst for water pretreatment process. The mesoporous Ti:Ash catalyst that doped with Ce was synthesized through wet impregnation method with 5%, 10%, and 15% weight percentage of Ce doped on 40:60 Ti:Ash. The photocatalytic properties were characterized through X-ray powder diffraction, scanning electron microscopy with energy-dispersive X-ray spectroscopy, N2 adsorption-desorption studies and diffuse reflectance UV–vis absorption spectroscopy. It is found that the Ti:Ash nanocomposites doped with Ce shifted the light absorption band-edge position to the visible region. Moreover, the Ce doped Ti:Ash has large surface area and pore diameter. The Ce doping could significantly improve the absorption edge of visible light and adjust the cut-off absorption wavelength from 404 nm to 451, 477 and 496 nm for 5%, 10% and 15% Ce-doped mesoporous Ti:Ash catalysts, respectively. As the Ce doping ratio increased, the band gaps decreased from 3.06 eV to 2.53 eV. The most contaminant reduction up to 45% was achieved when Ti:Ash:Ce 40:55:5 was used. Higher Ce loading on the photocatalyst may reduce the photocatalyst performance because supernumerary metal loading on TiO2 can block TiO2 defect sites which are necessary for the adsorption and photoactivation. The OPFA also acts as an adsorbent for some pollutants besides, reducing the water salinity. It can be deduced that the hybrid TiO2 photocatalyst that synthesized with OPFA and doped with Ce has huge potential to treat seawater prior to commercial seawater desalination process. Copyright © 2020 BCREC Group. All rights reserved 

scholarly journals Photocatalytic removal of cyclohexane on visible light-driven gallium oxide/carbon nitride composites prepared by impregnation method

2015 ◽  
Vol 11 (3) ◽  
Author(s):  
Shu Chin Lee ◽  
Wee Shern Chew ◽  
Hendrik O. Lintang ◽  
Leny Yuliati
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Gallium Oxide ◽  
Carbon Nitride ◽  
Light Irradiation ◽  
Impregnation Method ◽  
Visible Light Absorption ◽  
Photocatalytic Removal ◽  
Visible Light Driven

Carbon nitride is a material of interest for photocatalytic reactions due to its catalytic and visible light absorption properties. However, the photocatalytic activity is still low. Hence, modifications must be carried out to improve the photocatalytic activity of carbon nitride. In this work, a series of gallium oxide/carbon nitride composites with various gallium to carbon ratios (Ga/C = 1-50 mol%) was prepared by impregnation method for removal of cyclohexane under visible light irradiation for the first time. The successful preparation of gallium oxide/carbon nitride composites was supported by several characterization techniques. X-ray diffraction (XRD) patterns and diffuse reflectance UV-visible (DR UV-vis) spectra revealed that the increased Ga/C ratio resulted in the increased formation of Ga2O3. Furthermore, all the prepared composite samples also showed visible light absorption up to about 430 nm. In the photocatalytic removal of cyclohexane under 6 h of visible light irradiation, sample with low loading of 1 mol% Ga/C improved the photocatalytic activity of carbon nitride for two times. The high activity obtained on the gallium oxide (1 mol%)/carbon nitride composite clearly suggested the presence of synergic effect between small amount of gallium oxide and carbon nitride when they were combined. This study showed that a visible light-driven gallium oxide/carbon nitride composite could be prepared by impregnating a small amount of gallium oxide on carbon nitride and the composite is a potential photocatalyst for removal of cyclohexane under visible light irradiation.  

Photocatalytic Degradation of Diisopropanolamine in Heterogeneous Photo-Fenton System

2014 ◽  
Vol 917 ◽  
pp. 160-167 ◽  
Author(s):  
Raihan Mahirah Ramli ◽  
Chong Fai Kait ◽  
Abdul Aziz Omar
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Removal Efficiency ◽  
Cod Removal ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Similar Activity ◽  
Cod Removal Efficiency ◽  
Wet Impregnation Method ◽  
Fenton System

Photodegradation of 100 ppm diisopropanolamine (DIPA) was studied employing heterogeneous photo-Fenton system using iron modified TiO2 photocatalyst. A series of Fe/TiO2 photocatalysts were prepared via hydrolysis-hydrothermal and wet impregnation methods. Photocatalysts prepared using wet impregnation method was found to have similar activity under both UV and visible light. Addition of H2O2 during the photodegradation study obviously promoted the COD removal efficiency. When stoichiometric concentration of H2O2 was added, as high as 80% of COD was removed within 1.5 h reaction. Further modification is required to increase the photocatalyst performance in photodegradation of DIPA.

Self-assembled three-dimensional flowerlike Mn0.8Cd0.2S microspheres as efficient visible-light-driven photocatalysts for H2 evolution and CO2 reduction

2017 ◽  
Vol 7 (17) ◽  
pp. 3802-3811 ◽  
Author(s):  
Hong Liu ◽  
Jingchai Meng ◽  
Jiang Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Solvothermal Method ◽  
Three Dimensional ◽  
Co2 Reduction ◽  
H2 Evolution ◽  
Hierarchical Microspheres ◽  
Excellent Photocatalytic Activity ◽  
Visible Light Driven ◽  
Self Assembled

3D flowerlike Mn0.8Cd0.2S hierarchical microspheres assembled from nanosheets with excellent photocatalytic activity and stability were fabricated by a facile PVP-assisted solvothermal method.

scholarly journals Improved Visible-Light Photocatalytic Activity of g-C3N4/CuWO4 Nanocomposite for Degradation of Methylene Blue

Proceedings ◽  
2020 ◽  
Vol 41 (1) ◽  
pp. 43
Author(s):  
Afsaneh Rashidizadeh ◽  
Hossein Ghafuri ◽  
Zeynab Rezazadeh
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Solar Energy ◽  
Visible Light ◽  
Environmental Remediation ◽  
High Efficiency ◽  
Hydrothermal Process ◽  
Co2 Reduction ◽  
High Rate ◽  
Visible Light Driven

In recent years, heterogeneous semiconductor photocatalysts have attracted great attention in the arena of environmental remediation and solar energy conversion; because, sunlight energy is a renewable, cheap, and accessible source of energy and also converting solar energy to chemical energy can be declined the energy crisis and global warming. Development of visible light heterogeneous photocatalysts with high efficiency and chemical stability is important for catalysis researchers. Among different types of semiconductor material, polymeric graphitic carbon nitride (g-C3N4) with a medium band gap of about 2.7 eV has been widely applied in photodegradation of organic pollutants, water splitting, CO2 reduction, solar cells, energy storage, and organic synthesis. Unfortunately, due to the high rate recombination of photoinduced carriers, the photocatalytic performance of the bare g-C3N4 is still poor. Hence, many strategies including metal doping, noble metal deposition, and coupling with semiconductor composites have been employed to modify g-C3N4. Herein, we report the synthesis of g-C3N4/CuWO4 nanocomposite via a hydrothermal process. The prepared visible-light-driven nanocomposite exhibited an enhanced photocatalytic activity compared with bare g-C3N4 for the degradation of methylene blue (MB) under LED light irradiation.

scholarly journals Adsorption and Photocatalytic Study of Phenol Using Composites of Activated Carbon Prepared from Onion Leaves (Allium fistulosum) and Metallic Oxides (ZnO and TiO2)

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 574 ◽  
Author(s):  
Diego Felipe Hernández-Barreto ◽  
Jenny Paola Rodriguez-Estupiñán ◽  
Juan Carlos Moreno-Piraján ◽  
Rocío Sierra Ramírez ◽  
Liliana Giraldo
Keyword(s):  
Zinc Oxide ◽  
Photocatalytic Activity ◽  
Activated Carbon ◽  
Batch Adsorption ◽  
Allium Fistulosum ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Metallic Oxides ◽  
Activating Agent ◽  
Wet Impregnation Method

The aim of this study was to evaluate and compare the adsorption and photocatalytic activity of activated carbon-based photocatalysts. Titanium dioxide (TiO2) and zinc oxide (ZnO) were chosen as semiconductors to prepare composites with activated carbon by the wet impregnation method. Activated carbon was prepared using as starting material onion leaves (Allium fistulosum) and as activating agent phosphoric acid (H3PO4). Photooxidation and batch adsorption of phenol was studied to compare the efficiency of the materials prepared. The results showed that the composite AC–TiO2 has a greater photocatalytic activity and a better adsorption capacity compared to AC–ZnO composite.

Photodegradation of Methylene Blue over Cr Doped TiO2 and Cr Doped TiO2 Supported TUD-1 Photocatalysts

2015 ◽  
Vol 1109 ◽  
pp. 424-428 ◽  
Author(s):  
Yee Khai Ooi ◽  
Leny Yuliati ◽  
Siew Ling Lee
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Performance ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Wet Impregnation ◽  
Visible Light Driven ◽  
Synthesized Materials ◽  
Highly Porous

A series of visible light driven photocatalysts of Cr-doped TiO2 and Cr-doped TiO2 supported on TUD-1 have been successfully synthesized via surfactant-free sol-gel method followed by wet impregnation procedure. XRD analysis revealed that both anatase and rutile phases existed in Cr-doped TiO2 samples. After loading onto TUD-1, both Ti and Cr were incorporated in the highly porous siliceous matrix. As observed, more tetrahedrally coordinated Ti species was formed in Cr-doped TiO2 after supporting onto TUD-1. The photocatalytic performance of the synthesized materials was tested in the photodegradation of Methylene Blue under visible light irradiation. Results showed that 2.5 mol% Cr dopant gave the highest photocatytic activity to TiO2 in dye photodegradation. Besides, all the 2.5Cr-TiO2 supported on TUD-1 materials had higher photocatalytic activity than that of 2.5Cr-TiO2. Among the materials prepared, 2.5Cr-TiO2/30TUD-1 appeared as the most superior photocatalyst which gave the highest dye photodegradation of 75%.

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