Iron/Sulfur Co-Doped Titanium Dioxide Nanotubes: Optimization of the Photoelectrocatalytic Degradation of Phenol Red under Visible Light

2020 ◽  
Vol 847 ◽  
pp. 95-101
Author(s):  
Edgar Clyde R. Lopez ◽  
Nicole Elyse B. Saputil ◽  
Lance A. Loza ◽  
Fiona Fritz G. Camiguing ◽  
Marlon Jr. L. Mopon ◽  
...  
Keyword(s):  
Dye Degradation ◽  
Statistical Significance ◽  
Phenol Degradation ◽  
Quadratic Model ◽  
Phenol Red ◽  
Electron Hole ◽  
Iron Sulfur ◽  
Photoelectrocatalytic Degradation ◽  
Co Doped

Photoelectrocatalysis is a rapidly developing technology for degrading recalcitrant organic compounds in wastewater due to its ability to overcome electron-hole recombination. Herein, we synthesized Fe/S co-doped TiO2 nanotubes through an in-situ anodization technique. We developed a simple reduced quadratic model based on response surface modeling which can be used to adequately correlate the operating parameters with the photoelectrocatalytic performance of Fe/S-TiNTs in degrading phenol red. Predicted maximum dye degradation of 54.78% was achieved by the generated model using the optimized parameters: initial phenol red concentration = 5.22 mg L-1, applied voltage = 27.4 V, and dopant loading = 2.97 wt.%. Upon validation, experimental maximum phenol degradation of 53.24% was obtained, which agrees well with the predicted value within statistical significance. Overall, our model can be potentially used for process optimization within the design space studied.

Fe/S Co-Doped Titanium Dioxide Nanotubes: Optimization of the Photoelectrocatalytic Degradation Kinetics of Phenol Red

2021 ◽  
Vol 891 ◽  
pp. 49-55
Author(s):  
Edgar Clyde R. Lopez ◽  
Nicole Elyse B. Saputil ◽  
Lance A. Loza ◽  
Fiona Fritz G. Camiguing ◽  
Marlon L. Mopon Jr. ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Dye Degradation ◽  
Degradation Kinetics ◽  
Batch Reactor ◽  
Phenol Red ◽  
Titanium Dioxide Nanotubes ◽  
Photoelectrocatalytic Degradation ◽  
Cubic Model ◽  
Doped Titanium Dioxide ◽  
Optimized Conditions

Photoelectrocatalysis has emerged as a promising technology to degrade recalcitrant pollutants such as textile dyes in wastewater completely. Titanium dioxide is typically used as a photocatalyst, but its wide bandgap constrains its use to the use of ultraviolet light. To extend its use to the visible-light region, we doped titanium dioxide nanotubes with iron and sulfur. We used them as a photoelectrode for the photoelectrocatalytic degradation of a model pollutant – phenol red. Response surface methodology using a Box-Behnken design of experiments was used to investigate the effects of initial dye concentration, applied potential, and dopant loading on phenol red degradation kinetics. Statistical analysis showed that our reduced cubic model adequately correlates these parameters. The fastest dye degradation rate was achieved at the optimized conditions: initial phenol red concentration = 5.0326 mg L-1, applied voltage = 29.9686 V, and dopant loading = 1.2244 wt.%. Complete degradation of phenol red may be achieved after 11.77 hours of treatment under the optimized conditions in a batch reactor. Our model's robustness enables it to be used for process modeling and a basis for designing scaled-up photoelectrocatalytic reactors.

scholarly journals Improved Organic Dye Degradation Using Highly Efficient MXene Composites

2018 ◽  
Author(s):  
M. Abdullah Iqbal ◽  
S. Irfan Ali ◽  
Ayesha Tariq ◽  
Mohammad Z. Iqbal ◽  
Syed Rizwan
Keyword(s):  
Surface Area ◽  
Recombination Rate ◽  
Dye Degradation ◽  
Organic Pollutant ◽  
Sol Gel ◽  
Transition Metal Carbide ◽  
Light Spectrum ◽  
Electron Hole ◽  
Hole Recombination ◽  
Co Doped

Over the years, scarcity of fresh potable water has increased the demand for clean water. Meanwhile, with the advent of nanotechnology, the use of nanomaterials for photocatalytic degradation of pollutants in wastewaters has increased. Herein, a new type of nanohybrids of La and Mn co-doped bismuth ferrite (BiFeO3) nanoparticles embedded into transition metal carbide sheets (MXene) were prepared by a low-cost double solvent sol-gel method, and investigated for their photocatalytic activity. The photoluminescence results showed that pure BFO has highest electron hole recombination rate as compared to all the co-doped BFO/MXene nanohybrids. The larger surface area and higher electron-hole pair generation rate provides suitable environment for fast photo-degradation of organic molecules. The band gap of the prepared nanohybrids was tuned to 1.96 eV having largest BiFeO3 surface area (147 m2g−1) reported till date. Moreover, the BLFO/MXene and BLFMO-5/Mxene degraded the 92% organic pollutant from water in dark and remaining in light spectrum as compare to undoped BFO/Mxene due to enhancement of the surface area and electron-hole recombination rate upon doping. Therefore, these synthesized nanohybrids could be a promising candidate for photocatalytic applications in future.

scholarly journals Enhanced Visible-Light Photocatalytic Performance of SAPO-5-Based g-C3N4 Composite for Rhodamine B (RhB) Degradation

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3948
Author(s):  
Lingfang Qiu ◽  
Zhiwei Zhou ◽  
Mengfan Ma ◽  
Ping Li ◽  
Jinyong Lu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Redox Reactions ◽  
Photocatalytic Performance ◽  
Dye Degradation ◽  
Thermal Polymerization ◽  
Light Illumination ◽  
Electron Hole ◽  
Visible Light Illumination ◽  
Visible Light Photocatalytic

Novel visible-light responded aluminosilicophosphate-5 (SAPO-5)/g-C3N4 composite has been easily constructed by thermal polymerization for the mixture of SAPO-5, NH4Cl, and dicyandiamide. The photocatalytic activity of SAPO-5/g-C3N4 is evaluated by degrading RhB (30 mg/L) under visible light illumination (λ > 420 nm). The effects of SAPO-5 incorporation proportion and initial RhB concentration on the photocatalytic performance have been discussed in detail. The optimized SAPO-5/g-C3N4 composite shows promising degradation efficiency which is 40.6% higher than that of pure g-C3N4. The degradation rate improves from 0.007 min−1 to 0.022 min−1, which is a comparable photocatalytic performance compared with other g-C3N4-based heterojunctions for dye degradation. The migration of photo-induced electrons from g-C3N4 to the Al site of SAPO-5 should promote the photo-induced electron-hole pairs separation rate of g-C3N4 efficiently. Furthermore, the redox reactions for RhB degradation occur on the photo-induced holes in the g-C3N4 and Al sites in SAPO-5, respectively. This achievement not only improves the photocatalytic activity of g-C3N4 efficiently, but also broadens the application of SAPOs in the photocatalytic field.

Influence of in-situ and ex-situ Cu-Fe doping in K-OMS-2 catalysts on dye degradation via Fenton-like reaction with focus on catalytic properties and performances

2021 ◽  
Vol 23 ◽  
pp. 101030
Author(s):  
Kitirote Wantala ◽  
Totsaporn Suwannaruang ◽  
Janthip Palalerd ◽  
Prae Chirawatkul ◽  
Narong Chanlek ◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Dye Degradation ◽  
Ex Situ ◽  
Fe Doping

Promoting Hydrogen Evolution of g-C3N4 Based Photocatalyst by Indium and Phosphorus Co-doping

2021 ◽  
Author(s):  
Xiao-Hang Yang ◽  
Chi Cao ◽  
Zilong Guo ◽  
Xiaoyu Zhang ◽  
Yaxin Wang ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Post Treatment ◽  
Experimental Results ◽  
Indium Chloride ◽  
Co Doping ◽  
In Situ Copolymerization ◽  
Co Doped

Indium and phosphorus co-doped g-C3N4 photocatalyst (In,P-g-C3N4) was prepared by K2HPO4 post-treatment of indium doped g-C3N4 photocatalyst (In-g-C3N4) derived from in-situ copolymerization of dicyandiamide and indium chloride. The experimental results...

scholarly journals Quantifying the influence of natural climate variability on in situ measurements of seasonal total and extreme daily precipitation

2021 ◽  
Author(s):  
Mark D. Risser ◽  
Michael F. Wehner ◽  
John P. O’Brien ◽  
Christina M. Patricola ◽  
Travis A. O’Brien ◽  
...  
Keyword(s):  
Climate Variability ◽  
Extreme Precipitation ◽  
Southern Oscillation ◽  
Statistical Significance ◽  
In Situ Measurements ◽  
Climate Indices ◽  
Natural Climate Variability ◽  
Modes Of Variability ◽  
Natural Climate

AbstractWhile various studies explore the relationship between individual sources of climate variability and extreme precipitation, there is a need for improved understanding of how these physical phenomena simultaneously influence precipitation in the observational record across the contiguous United States. In this work, we introduce a single framework for characterizing the historical signal (anthropogenic forcing) and noise (natural variability) in seasonal mean and extreme precipitation. An important aspect of our analysis is that we simultaneously isolate the individual effects of seven modes of variability while explicitly controlling for joint inter-mode relationships. Our method utilizes a spatial statistical component that uses in situ measurements to resolve relationships to their native scales; furthermore, we use a data-driven procedure to robustly determine statistical significance. In Part I of this work we focus on natural climate variability: detection is mostly limited to DJF and SON for the modes of variability considered, with the El Niño/Southern Oscillation, the Pacific–North American pattern, and the North Atlantic Oscillation exhibiting the largest influence. Across all climate indices considered, the signals are larger and can be detected more clearly for seasonal total versus extreme precipitation. We are able to detect at least some significant relationships in all seasons in spite of extremely large (> 95%) background variability in both mean and extreme precipitation. Furthermore, we specifically quantify how the spatial aspect of our analysis reduces uncertainty and increases detection of statistical significance while also discovering results that quantify the complex interconnected relationships between climate drivers and seasonal precipitation.

In-situ growth of high-performance (Ag, Sn) co-doped CoSb3 thermoelectric thin films

2021 ◽  
Author(s):  
Zhuang-Hao Zheng ◽  
Jun-Yun Niu ◽  
Dong-Wei Ao ◽  
Bushra Jabar ◽  
Xiao-Lei Shi ◽  
...  
Keyword(s):  
Thin Films ◽  
High Performance ◽  
In Situ Growth ◽  
Thermoelectric Thin Films ◽  
Co Doped

scholarly journals Heart-related mortality after postoperative breast irradiation in patients with ductal carcinoma in situ in the contemporary radiotherapy era

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu Jin Lim ◽  
Jaemoon Koh
Keyword(s):  
Competing Risks ◽  
Ductal Carcinoma In Situ ◽  
Carcinoma In Situ ◽  
Ductal Carcinoma ◽  
Statistical Significance ◽  
Young Patients ◽  
Subdistribution Hazard ◽  
The Impact ◽  
Related Mortality

AbstractAlthough radiation-induced cardiotoxicity has been addressed, its prognostic relevance to modern radiotherapy (RT) techniques is unclear. This study assessed the impact of adjuvant RT on heart-related deaths in patients with ductal carcinoma in situ. Patients who underwent adjuvant RT after breast-conserving surgery between 1988 and 2008 were identified from the Surveillance, Epidemiology, and End Results database. Kaplan‒Meier and competing risks analyses were conducted after propensity score-matching according to tumor laterality. A total of 41,526 propensity-matched patients were identified (n = 20,763 for either left- or right-sided tumor). In the analysis of the cumulative incidence of heart-related mortality events, there was a greater risk increment in the left-sided group over the first to second decades after RT in patients aged ≤ 50 years (P = 0.048). Competing risks analysis of the young patients showed that left-sided RT was associated with higher heart-related mortality rates (Grey’s test, P = 0.049). The statistical significance remained after adjusting for other covariates (subdistribution hazard ratio 2.35; 95% confidence interval 1.09‒5.10). Regarding the intrinsic effect of modern RT techniques, further strategies to reduce heart-related risks are needed for young patients. Close surveillance within an earlier follow-up period should be considered for these patients in clinics.

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