scholarly journals Nanocrystalline N-DopedTiO2Powders: Mild Hydrothermal Synthesis and Photocatalytic Degradation of Phenol under Visible Light Irradiation

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Junna Xu ◽  
Feng Wang ◽  
Wenxiu Liu ◽  
Wenbin Cao
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Ph Value ◽  
Guanidine Hydrochloride ◽  
Initial Pressure ◽  
Light Irradiation ◽  
Titanyl Sulfate ◽  
Visible Absorption ◽  
Light Region ◽  
Initial Ph

Nitrogen-doped TiO2powders have been prepared using technical guanidine hydrochloride, titanyl sulfate, and urea as precursors via a mild hydrothermal method under initial pressure of 3MPa,150∘Cholding for 2h without any postheat treatment for crystallization. The nanocrystalline N-doped TiO2powders were composed of anatase TiO2by XRD. The grain size was estimated as about 10 nm, and the BET specific surface area of the powder was measured as 154.7 m2/g. The UV-visible absorption spectra indicated that the absorption edge of the N-doped TiO2powders had been red shifted into the visible light region. The photocatalytic performance of the synthesized powders was evaluated by degradation of phenol under visible light irradiation. And the effects of the catalyst load and the initial pH value on the photodegradation were also investigated.

Optimum Conditions of Ag/BiVO4 Photocatalytic Performance on Degradation of Paracetamol by Response Surface Methodology

2014 ◽  
Vol 1073-1076 ◽  
pp. 336-339
Author(s):  
Tian Qi Li ◽  
Hui Wang ◽  
Ya Qi Zhu ◽  
Zhao Yong Bian
Keyword(s):  
Response Surface Methodology ◽  
Visible Light ◽  
Response Surface ◽  
Visible Light Irradiation ◽  
Ph Value ◽  
Light Irradiation ◽  
Catalyst Loading ◽  
Optimum Conditions ◽  
Initial Ph ◽  
Ag Catalyst

Response surface methodology was applied to investigate the optimum degradation conditions of paracetamol using Ag/BiVO4 photocatalysts under the visible light irradiation. Experimental results show that the optimum degradation conditions were: catalyst dosage quantity was 80 mg, Ag-catalyst loading was 5%, and the initial pH value of the solution was 6, respectively. Under this condition, the degradation efficiency of paracetamol was 77.9% within 5 h under the visible light irradiation.

Synthesis of Uranium Doped TiO2 Nanomaterial and its Visible Light Degradation Property

2010 ◽  
Vol 148-149 ◽  
pp. 1208-1211 ◽  
Author(s):  
Shao You Liu ◽  
Qing Ge Feng
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Ph Value ◽  
Pure Tio2 ◽  
Anatase Tio2 ◽  
Light Irradiation ◽  
Reaction Route ◽  
Light Region ◽  
Tio2 Nanomaterials ◽  
Visible Light Degradation

Uranium doped TiO2 (U-TiO2) nanomaterials, determined by scanning electron micro- graphy (SEM), were successfully synthesized via a simple, effective and environmental benign solid state reaction route. The characterizations via XRD and XPS showed that the uranium has been entered into the framework of anatase TiO2. The DRUV-Vis revealed that the adsorption region of U-TiO2 nanomaterials shifts to the visible light region compared with the pure TiO2. Moreover, the U-TiO2 nanomaterials for photodegradation of quinoline showed a good photocatalytic properties under visible light irradiation. At 298K, within 60 min visible light irradiation, 54.9 % of the initial quinoline was degraded by the U-TiO2 (U/Ti=3:20) catalyst. The visible light degradation rate of the U-TiO2 nanomaterials is negative to the pH value of surface but positive to the visible light absorption range.

scholarly journals Study on synthesis of MoS2 modified g-C3N4 materials for treatment of Direct black 38 dye

2018 ◽  
Vol 9 (3) ◽  
pp. 169-176
Author(s):  
Thi Lan Phung ◽  
Thi Kim Giang Nguyen
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Photocatalytic Performance ◽  
Ph Value ◽  
Light Irradiation ◽  
Order Kinetic ◽  
Two Factors ◽  
Pseudo Second Order ◽  
Enhanced Adsorption ◽  
Adsorption Desorption

Pure g-C3N4 and MoS2 modified g-C3N4 materials were synthesized using a facile heating method and a low-temperature hydrothermal method, respectively. The obtained samples were characterized by XRD pattern and N2 adsorption-desorption technique at 77K. The adsorption and photocatalytic performance of all obtained samples were investigated by discoloration of direct black 38 dye in the dark and under visible light irradiation. The results showed that all obtained samples exhibited good discoloration efficiency of direct black 38 dye. The two factors including pH values and Mo loading effected mainly on elimination efficiency of direct black 38 dye. MoS2 modified g-C3N4 materials possessed the more enhanced adsorption and photocatalytic performance in comparison to pure g-C3N4 at pH value of 3.5, with adsorbent dosage of 0.1 g/L. Furthermore, it was found that the adsorption process and photo-catalysis simultaneously occurred under visible light irradiation and followed up a pseudo-second-order kinetic reaction of Langmuir - Hinshelwood model. g-C3N4 và g-C3N4 biến tính bởi MoS2 đã được tổng hợp theo phương pháp nung đơn giản và phương pháp thủy nhiệt ở nhiệt độ thấp tương ứng. Các mẫu tổng hợp đã được đánh giá đặc trưng bởi các phương pháp hiện đại như giản đồ nhiễu xạ tia X, phương pháp hấp phụ-khử hấp phụ N2 ở 77K. Khả năng hấp phụ và quang hóa xúc tác của các vật liệu tổng hợp đã được nghiên cứu bởi quá trình phân hủy màu thuốc nhuộm direct black 38 trong điều kiện bóng tối và chiếu sáng bởi ảnh sáng nhìn thấy của đèn chiếu sáng sợi đốt wolfram (220V-100W). Các kết quả nghiên cứu chỉ ra rằng các mẫu tổng hợp đều có hiệu suất xử lý màu cao đối với thuốc nhuộm direct black 38. Hai yếu tố gồm pH dung dịch và hàm lượng MoS2 ảnh hưởng chính đến hiệu suất xử lý màu direct black 38. g-C3N4 biến tính bởi MoS2 luôn thể hiện hiệu suất hấp phụ và quang hóa cao hơn so với g-C3N4 tinh khiết. Hơn nữa, khi được chiếu sáng bởi ánh sáng nhìn thấy thì quá trình hấp phụ và quá trình quang hóa thuốc nhuộm direct black 38 trên các vật liệu tổng hợp đã xảy ra đồng thời và mô hình Langmuir - Hinshelwood động học bậc 2 đã được đề xuất cho quá trình này.

Preparation of N-Doped TiO2 Photocatalytic Paint and its Sterilization Performance under Visible-Light Irradiation

2007 ◽  
Vol 336-338 ◽  
pp. 1964-1967
Author(s):  
Xiao Ning Zhang ◽  
Wen Bin Cao ◽  
Yan Hong Li ◽  
Fan Yong Ran
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Anatase Tio2 ◽  
Light Irradiation ◽  
Counting Method ◽  
Latex Paint ◽  
Light Region ◽  
Colony Counting ◽  
Nanocrystalline Anatase Tio2 ◽  
Light Absorbance

A new functional photocatalytic paint was prepared by adding N-doped nanocrystalline anatase TiO2 powders into self-engineered oxidation resistance latex paint system. The property of the UV-Vis light absorbance of the paint was characterized. The effects of the amount, types, and the introducing methods of the TiO2 in the paints on the behavior of the UV absorption, photocatalytic properties of the paint were systematically investigated. UV-Vis absorption spectra reveal that the ultraviolet light can strongly be absorbed by the paints. The absorption edge of the N-doped nanocrystalline anatase powders modified paint has red-shifted to visible light region. The colony counting method is used to study its sterilization performance under visible light irradiation. The sterilization experiments show that the rate of sterilizing staphylococcal bacteria by the N-doped TiO2 modified paint can exceed more than 99% after the paint has been irradiated by the visible light for 2 to 4 hours.

Visible-Light Activity of N-Doped TiO2 Powders and their Applications

2007 ◽  
Vol 544-545 ◽  
pp. 167-170 ◽  
Author(s):  
Wen Bin Cao ◽  
Yi Wei ◽  
Yan Hong Li ◽  
Xiao Ning Zhang
Keyword(s):  
Aqueous Solution ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Guanidine Hydrochloride ◽  
Anatase Tio2 ◽  
Light Irradiation ◽  
Latex Paint ◽  
Doped Tio2 ◽  
Light Activity ◽  
Xrd Patterns

Nitrogen-doped TiO2 has been prepared by calcining technical grade guanidine hydrochloride and commercial anatase TiO2 powders. XRD patterns indicate that the prepared powders are composed of anatase. XPS results show that N atoms have been incorporated into the lattice of anatase. UV-Vis reflectance spectra show that the light absorption of the synthesized N-doped anatase powders has red-shifted well into visible-light region. Degradation of methylene blue (MB) aqueous solution by N-doped anatase has been investigated by UV-Vis light spectrophotometer. The 400-mL 10 mg/L aqueous solution of MB could be degraded with 4 g N-doped TiO2 within 4.5 hrs of visible light irradiation. Photocatalytic paint was prepared by adding the synthesized N-doped nanocrystalline anatase TiO2 powders into self-engineered oxidation resistance latex paint system. The effects of the amount and types of the TiO2 in the paints on the sterilization were systematically investigated. The colony counting method was used to study its sterilization performance under visible light irradiation. The sterilization experiments show that the rate of sterilizing E. coli by the N-doped TiO2 modified paint can exceed more than 99% after irradiation by the visible light for 2 to 4 hours.

Preparation of Nanocrystalline W-Doped TiO2 Powders and their Photocatalytic Properties under Visible Light Irradiation

2011 ◽  
Vol 695 ◽  
pp. 489-492 ◽  
Author(s):  
Yun Ting Song ◽  
Wei Na Shao ◽  
Wen Bin Cao
Keyword(s):  
Visible Light ◽  
Specific Surface ◽  
Visible Light Irradiation ◽  
Atomic Ratio ◽  
Light Irradiation ◽  
Uniform Size ◽  
Surface Areas ◽  
Light Region ◽  
Good Crystallinity ◽  
Photocatalytic Activities

Nanocrystalline W-doped TiO2 powders with different initial W/Ti ratio in starting materials have been prepared by hydrothermal method. The phase composition, morphologies, specific surface areas and the photocatalytic activities under visible light irradiation of the synthesized powders have been characterized. XRD identification reveals that the synthesized powders were composed of anatase. No rutile has been detected in the products. The specific surface area of the powders was ranged from 185 to 210 m2/g by BET measurement. The averaged grain size of the powders was calculated as about 12 nm by Scheller's method. Uniform size distribution and good crystallinity have been confirmed by TEM. UV-Vis spectra show that the absorption edges of the synthesized W-doped TiO2 powders with different nominal doping concentration of Wions have been red-shifted into visible light region, which suggests that the W ions have been doped into the lattice of TiO2. In our case, W-doped TiO2 with initial W/Ti atomic ratio of 1% in starting materials has the best photocatalytic activities when decompose the Methylblue in its aqueous solution, which is consistent with that of the theoretical results from our previous work.

scholarly journals A Comparative Study of Microcystin-LR Degradation by UV-A, Solar and Visible Light Irradiation Using Bare and C/N/S-Modified Titania

Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 877 ◽  
Author(s):  
Khedr ◽  
El-Sheikh ◽  
Abdeldayem ◽  
Ismail ◽  
Kowalska ◽  
...  
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Degradation Rate ◽  
Ph Value ◽  
Mesoporous Structure ◽  
Light Irradiation ◽  
Solar Irradiation ◽  
Bare Tio2 ◽  
Cyanobacteria Blooms ◽  
Degradation Rate Constant

In an endeavor to tackle environmental problems, the photodegradation of microcystin-LR (MC-LR), one of the most common and toxic cyanotoxins, produced by the cyanobacteria blooms, was examined using nanostructured TiO2 photocatalysts (anatase, brookite, anatase–brookite, and C/N/S co-modified anatase–brookite) under UV-A, solar and visible light irradiation. The tailoring of TiO2 properties to hinder the electron–hole recombination and improve MC-LR adsorption on TiO2 surface was achieved by altering the preparation pH value. The highest photocatalytic efficiency was 97% and 99% with degradation rate of 0.002 mmol L−1 min−1 and 0.0007 mmol L−1 min−1 under UV and solar irradiation, respectively, using a bare TiO2 photocatalyst prepared at pH 10 with anatase to brookite ratio of ca. 1:2.5. However, the bare TiO2 samples were hardly active under visible light irradiation (25%) due to a large band gap. Upon UV, solar and vis irradiation, the complete MC-LR degradation (100%) was obtained in the presence of C/N/S co-modified TiO2 with a degradation rate constant of 0.26 min−1, 0.11 min−1 and 0.04 min−1, respectively. It was proposed that the remarkable activity of co-modified TiO2 might originate from its mixed-phase composition, mesoporous structure, and non-metal co-modification.

Synthesis of Mn-N-Codoped TiO2 Photocatalyst and its Photocatalytic Reactivity under Visible Light Irradiation

2009 ◽  
Vol 620-622 ◽  
pp. 683-686 ◽  
Author(s):  
Yun Hu ◽  
Xia Zhang ◽  
Chao Hai Wei
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Doping Concentration ◽  
Synthesis Method ◽  
Light Irradiation ◽  
Doped Tio2 ◽  
Codoped Tio2 ◽  
Light Region ◽  
Optimal Value

Visible-light responsible Mn-N-codoped TiO2 nanocrystal photocatalysts were synthesized for the first time by a simple hydrothermal synthesis method. X-ray powder diffraction (XRD) measurement indicated that all of the photocatalysts have an anatase crystallite structure and the increase of the doping concentration had less effect on the structure and particle size. Comparing to N-doped TiO2, a shift of the absorption edge of Mn-N-codoped TiO2 to a lower energy and a stronger absorption in the visible light region were observed. The Mn-N-codoped TiO2 showed a higher photocatalytic reactivity than undoped TiO2 and N-doped TiO2 for the photodegradation of rhodamine B (RhB) under visible light irradiation. The doping concentration had an optimal value, according to the highest photocatalytic activity. This suggested that Mn and N codoping has important effects on the improvement of visible-light responsible photocatalytic activity.

Photocatalytic Degradation of Methylene Blue Aqueous Solution under Visible Light Irradiation by Using N-Doped Titanium Dioxide

2007 ◽  
Vol 336-338 ◽  
pp. 1972-1975 ◽  
Author(s):  
Yan Hong Li ◽  
Wen Bin Cao ◽  
Fan Yong Ran ◽  
Xiao Ning Zhang
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Guanidine Hydrochloride ◽  
Visible Region ◽  
High Photocatalytic Activity ◽  
Light Irradiation ◽  
Nanocrystalline Tio2 ◽  
Doped Tio2

N-doped TiO2 powders with high photocatalytic activity under visible-light irradiation have been prepared by calcining anatase nanocrystalline TiO2 powders and guanidine hydrochloride at 350 °C, 450 °C, 550 °C and 650 °C with the holding time ranged from 1.5 h to 3 h, respectively. The guanidine hydrochloride content was varied from 1 to 6 M for the experiments. XRD patterns indicate that all the powders are anatase crystalline phase. The specific surface area is 25~45 m2/g measured by BET method. XPS results show that N atoms were incorporated into the lattice of TiO2 and the amount of N doped in TiO2 is reached up to 8.26 at%. UV-Vis absorption spectra show that the absorption edge of the synthesized N-doped TiO2 powders, calcined at 350 °C for 2.5 h, has red-shifted well into visible region up to 700 nm. Degradation of methylene blue (MB) aqueous solution has been investigated by UV-Vis light spectrophotometer. The 400-mL 10 mg/L aqueous solution of methylene blue could be degraded completely with 4 g N-doped TiO2 within 4.5 h of visible light irradiation.

scholarly journals Enhancing the photocatalytic activity of Cu0.25Zn0.75S nanodisks by metallic Ag loading in the visible-light region

RSC Advances ◽  
2019 ◽  
Vol 9 (24) ◽  
pp. 13787-13796 ◽  
Author(s):  
Jinyang Zhang ◽  
Fuyan Kang ◽  
Hao Peng ◽  
Jing Wen ◽  
Xiaogang Zheng
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Organic Pollutants ◽  
Visible Light Irradiation ◽  
Rhodamine B ◽  
Methyl Violet ◽  
Light Irradiation ◽  
Visible Light Region ◽  
Ciprofloxacin Hydrochloride ◽  
Light Region

Ag-loaded Cu0.25Zn0.75S (Ag/Cu0.25Zn0.75S) photocatalysts were synthesized for the photodegradation of organic pollutants such as rhodamine B (RhB), methyl violet (MV) and ciprofloxacin hydrochloride (CIP) under visible-light irradiation.

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