scholarly journals Electrodeposition and Catalytic Performance of Hydrophobic PbO2 Electrode Modified by Surfactant OP-10

2021 ◽  
Author(s):  
Ying Shen ◽  
yudong Li ◽  
Yingwu Yao ◽  
Yun Xia ◽  
Mengyao Jiao ◽  
...  
Keyword(s):  
Supporting Electrolyte ◽  
Hydrophobic Surface ◽  
Catalytic Performance ◽  
Industrial Applications ◽  
Side Reactions ◽  
Dye Wastewater ◽  
Mechanism Study ◽  
Good Service ◽  
Pbo2 Electrode ◽  
Initial Ph

Abstract A hydrophobic PbO2 electrode modified by surfactant OP-10 was prepared by electrodeposition. The electrode has good hydrophobic surface (the hydrophobic angle can reach 123°), high over point oxygen evolution (OEP) (1.60 V vs. SCE), and good service life (81 h). The electrode morphology and electrodeposition mechanism study found that the addition of OP-10 can help to build a dense PbO2 electrode surface, reduce the occurrence of side reactions, and promote the positive deposition of PbO2. As much as 30 mg L-1 of methylene blue, as the simulated pollutant, could be degraded in 80 min under conditions of 50 mA cm-2, initial pH = 7, and a concentration of supporting electrolyte of 0.15 mol L-1, which could be easily reached. Moreover, a practical dye wastewater was employed, proving the OP-10 modified PbO2 electrode is suitable for industrial applications, where the COD of dye wastewater can be reduced from 330 to 4 mg L-1 in 120 min.

Study on Electrochemical Degradation of Acid Scarlet 3R

2011 ◽  
Vol 71-78 ◽  
pp. 3071-3074
Author(s):  
Jun Sheng Hu ◽  
Yue Li ◽  
Zhuo Wang
Keyword(s):  
Current Density ◽  
Electrolyte Concentration ◽  
Ph Value ◽  
Removal Rate ◽  
Supporting Electrolyte ◽  
Color Removal ◽  
Alkaline Condition ◽  
Dye Wastewater ◽  
Initial Concentration ◽  
Initial Ph

Based on a static experiment, this study researched the electrochemical oxidation process of simulated dye wastewater containing Acid Scarlet 3R in the two-dimensional electrolysing cell. This experiment investigated the effect of such various factors as current density, initial concentration, supporting electrolyte concentration, and the initial pH value on the color removal. The results of the experiment clearly indicated that the rate of color removal increased when the current density was increasing gradually; it decreased when the initial concentration was increasing; it originally increased and then decreased when concentration of electrolytes was increasing; alkaline condition was not conducive to the removal of color, and the effect of decolorization was better under an acid condition than under an alkaline condition. The optimum condition of disposing of dye wastewater is when the current density is 7Am/cm², electrolyte concentration is 0.04mol/L, pH=2.5, under the condition of which the color removal rate could be 96.06%.

Electrochemical Treatment of Simulated Dye Wastewater

2012 ◽  
Vol 441 ◽  
pp. 555-558
Author(s):  
Feng Tao Chen ◽  
San Chuan Yu ◽  
Xing Qiong Mu ◽  
Shi Shen Zhang
Keyword(s):  
Current Density ◽  
Oxygen Demand ◽  
Electrochemical Treatment ◽  
Dye Wastewater ◽  
Electrolysis Time ◽  
Electrochemical Degradation ◽  
Mild Conditions ◽  
Thermal Decomposition Method ◽  
Initial Ph ◽  
Effects Of Ph

The Ti/SnO2-Sb2O3/PbO2 electrodes were prepared by thermal decomposition method and its application in the electrochemical degradation of a heteropolyaromatic dye, Methylene blue (MB), contained in simulated dye wastewater were investigated under mild conditions. The effects of pH, current density and electrolysis time on de-colorization efficiency were also studied. Chemical oxygen demand (COD) was selected as another parameter to evaluate the efficiency of this degradation method on treatment of MB wastewater. The results revealed that when initial pH was 6.0, current density was 50 mA·cm2, electrolysis time was 60 min, Na2SO4 as electrolyte and its concentration was 3.0 g·dm3, the de-colorization and COD removal efficiency can reach 89.9% and 71.7%, respectively.

scholarly journals Directed Evolution of a Homodimeric Laccase from Cerrena unicolor BBP6 by Random Mutagenesis and In Vivo Assembly

2018 ◽  
Vol 19 (10) ◽  
pp. 2989 ◽  
Author(s):  
Ji Zhang ◽  
Fuying Ma ◽  
Xiaoyu Zhang ◽  
Anli Geng
Keyword(s):  
Directed Evolution ◽  
Laccase Activity ◽  
Catalytic Properties ◽  
Random Mutagenesis ◽  
Catalytic Performance ◽  
Industrial Applications ◽  
Subunit Interaction ◽  
Cerrena Unicolor ◽  
Protein Model

Laccases have great potential for industrial applications due to their green catalytic properties and broad substrate specificities, and various studies have attempted to improve the catalytic performance of these enzymes. Here, to the best of our knowledge, we firstly report the directed evolution of a homodimeric laccase from Cerrena unicolor BBP6 fused with α-factor prepro-leader that was engineered through random mutagenesis followed by in vivo assembly in Saccharomyces cerevisiae. Three evolved fusion variants selected from ~3500 clones presented 31- to 37-fold increases in total laccase activity, with better thermostability and broader pH profiles. The evolved α-factor prepro-leader enhanced laccase expression levels by up to 2.4-fold. Protein model analysis of these variants reveals that the beneficial mutations have influences on protein pKa shift, subunit interaction, substrate entrance, and C-terminal function.

scholarly journals Electrochemical oxidation of m-cresol purple dye in aqueous media

2015 ◽  
Vol 50 (4) ◽  
pp. 305-313
Author(s):  
Sajjad Khezrianjoo ◽  
Hosakere Doddarevanna Revanasiddappa
Keyword(s):  
Electrochemical Oxidation ◽  
Applied Voltage ◽  
Supporting Electrolyte ◽  
Aqueous Media ◽  
Degradation Process ◽  
Cell System ◽  
Electrolysis Cell ◽  
System A ◽  
Initial Ph ◽  
Indicator Dye

The present investigation showed that the indicator dye m-cresol purple (mCP) was degraded in a laboratory scale, undivided electrolysis cell system. A platinum anode was used for generation of chlorine in the dye solution. The influence of supporting electrolyte, applied voltage, pH, initial dye concentration and temperature were studied. The ultraviolet-visible spectra of samples during the electrochemical oxidation showed rapid decolorization of the dye solution. During the electrochemical degradation process, dye concentration and current were measured to evaluate the energy consumption and current efficiency. After 10 minutes of electrolysis, a solution containing 20 mg/L mCP showed complete color removal at a supporting electrolyte concentration of 1 g/L NaCl, initial pH 6.7, temperature 25 °C and applied voltage 5 V; however, when pH was kept at 6.7, a higher rate constant was observed. There was good fit of the data to pseudo-first-order kinetics for dye removal in all experiments. Dependence of the decolorization rate on the initial mCP concentration can be described as roα[mCP]o−0.98. The apparent activation energy for the electrochemical decolorization of mCP was determined to be −6.29 kJ/mol.

The electrocatalytic hydrogenation of fused poly cyclic aromatic compounds at Raney nickel electrodes: the influence of catalyst activation and electrolysis conditions

1990 ◽  
Vol 68 (7) ◽  
pp. 1218-1227 ◽  
Author(s):  
Denis Robin ◽  
Michel Comtois ◽  
Anna Martel ◽  
René Lemieux ◽  
Amoy Kam Cheong ◽  
...  
Keyword(s):  
Raney Nickel ◽  
Supporting Electrolyte ◽  
Aqueous Sodium Hydroxide ◽  
Constant Current ◽  
Electrocatalytic Hydrogenation ◽  
Catalyst Activation ◽  
Nickel Electrodes ◽  
Initial Ph ◽  
Raney Ni ◽  
Tetrabutylammonium Chloride

The electrocatalytic hydrogenation (ECH) of phenanthrene, anthracene, and naphthalene has been investigated under constant current at Raney nickel electrodes in a mixed aqueous organic medium. The influence of various parameters on the efficiency of the process determined by the current efficiency (a measure of the competition between hydrogenation and hydrogen evolution, the only two electrochemical processes occurring), the extent of hydrogenation (yield of octahydro-derivatives), and the conversion rate was studied with phenanthrene. The best conditions were ethylene glycol or propylene glycol as cosolvent containing between 1.5 to 5% of water, a neutral or slightly acidic medium containing boric acid (0.1 M) as buffer (initial pH of 2.6, final pH of 6.0–6.2), sodium chloride or tetrabutylammonium chloride as supporting electrolyte, a temperature of 80° C, and a current density of 42 to 84 mA/cm2. The most active electrodes (consisting of Raney Ni particles dispersed in a nickel matrix and surrounded by a layer of porous nickel) were obtained by leaching the dispersed alloy particles at 75 °C for 7 h in 30% aqueous sodium hydroxide. The electrohydrogenation stopped at derivatives with a single aromatic ring, namely the octahydrophenanthrenes, octahydroanthracenes, and tetralin. In a non-buffered medium, tetrahydrophenanthrene could be obtained with selectivities of 80% or better. Keywords: electrocatalytic hydrogenation, Raney nickel electrodes, phenanthrene, anthracene, naphthalene.

Electrochemical Oxidation of Azo Dye Wastewater Using Graphene-Based Electrode Materials

2019 ◽  
Vol 19 (11) ◽  
pp. 7308-7314
Author(s):  
Jinyan Li ◽  
Qingsong Guan ◽  
Junming Hong ◽  
Chang-Tang Chang
Keyword(s):  
Electrochemical Oxidation ◽  
Current Density ◽  
Electrode Materials ◽  
Supporting Electrolyte ◽  
Performance Comparison ◽  
Carbon Cloth ◽  
Reactive Black 5 ◽  
Dye Wastewater ◽  
Composite Electrodes ◽  
Initial Concentration

Composite electrodes with different graphene (GN)/TiO2 ratios and nano-activated carbon electrodes were prepared for electrocatalytic performance comparison. The electrodes were loaded with platinum (Pt) by use of chloroplatinic acid to promote their performance. Reactive Black 5 (RBk5) dye wastewater was treated as a challenging pollutant by use of advanced electrochemical oxidation technology. The composite materials were characterized by Transmission Electron Microscope (TEM), Field Emission Scanning Electron Microscopy (FE-SEM), and Energy Disperse Spectroscopy (EDS). Results showed that the graphene electrode was prepared successfully and verified because all elements were uniformly loaded on the conductive carbon cloth. The effects of several operating parameters including material types, pH, initial concentration of RBk5, and current density on the removal performance of RBk5 were also assessed. The supporting electrolyte was NaCl solution of 1 g L−1. The concentration of RBk5 was detected using an ultraviolet spectrophotometer with a detection wavelength of 600 nm. The optimum parameters of the experiment were GN/TiO2 ratio of 1:4 and pH of 6.6. The removal efficiency of RBk5 could be higher than 95% under an initial concentration of RBk5 of 5 ppm and a current density of 2.5 mA·cm-2 when reaction time was 30 min.

scholarly journals Catalytic Performance of SBA-15-Supported Poly (Styrenesulfonic Acid) in the Esterification of Acetic Acid with n-Heptanol

2020 ◽  
Vol 10 (17) ◽  
pp. 5835
Author(s):  
Abdulaziz Ali Alghamdi ◽  
Yahya Musawi Mrair ◽  
Fahad A. Alharthi ◽  
Abdel-Basit Al-Odayni
Keyword(s):  
Acetic Acid ◽  
Sulfonic Acid ◽  
Active Sites ◽  
Structural Characteristics ◽  
High Surface ◽  
High Surface Area ◽  
Reaction Times ◽  
Hydrophobic Surface ◽  
Catalytic Performance ◽  
Catalyst Load

A polystyrene sulfonic acid-functionalized mesoporous silica (SBA-15-PSSA) catalyst was synthesized via an established multistep route, employing 2-bromo-2-methylpropionyl bromide as initiator of atom transfer radical polymerization. Fourier-transform infrared spectroscopy, thermogravimetric/differential thermal, Brunauer–Emmett–Teller, and transmission electron microscopy analyses revealed outstanding structural characteristics of the catalyst, including highly ordered mesopores, high surface area (726 m2/g), and adequate estimated concentrations of active sites (0.70 mmol H+/g). SBA-15-PSSA’s catalytic performance was evaluated in the esterification of acetic acid and n-heptanol as a model system at various temperatures (50–110 °C), catalyst loads (0.1–0.3 g), and reaction times (0–160 min). The conversion percentage of acetic acid was found to increase with the temperature, catalyst load, and reaction time. Furthermore, results indicated a fast conversion in the first 20 min of the reaction, with remarkable conversion values at 110 °C, reaching 86%, 94%, and 97% when the catalyst load was 0.1, 0.2, and 0.3 g, respectively; notably, at this temperature, 100% conversation was achieved after 60 min. At 110 °C, the reaction conducted in the presence of 0.3 g of catalyst displayed more than 6.4 times the efficiency of the uncatalyzed reaction. Such activity is explained by the concomitant presence in the polymer of strong sulfonic acid moieties and a relatively high hydrophobic surface, with adequate numbers of active sites for ester production.

Degradation of Acid Dyes by Resin D072 Load Fe (II) Catalyst

2011 ◽  
Vol 183-185 ◽  
pp. 1359-1363
Author(s):  
Bin Song Wang ◽  
Lin Hong Li ◽  
Fu Yi Cui ◽  
Jie Zhang
Keyword(s):  
Reaction Temperature ◽  
Experimental Results ◽  
Dye Wastewater ◽  
Acid Dye ◽  
Acid Dyes ◽  
Heterogeneous Fenton ◽  
Fenton Catalyst ◽  
Initial Ph ◽  
Heterogeneous Fenton Catalyst ◽  
Optimal Ph

Degradation of acid dye wastewater has been studued by using resin D072 load Fe2+ as heterogeneous Fenton catalyst. The effects of the initial PH of solution,the H2O2 adding doses,the amount of catalyst and the reaction temperature on the degradation of acid dye wastewater have been investigated in detail. According to experimental results, the optimal pH was pH3, the H2O2 adding doses was 333mg/L, the amount of catalyst and the reaction temperature were 10g/L and 27°C, respectively.

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