scholarly journals Using BiVO4/CuO-Based Photoelectrocatalyzer for 4-Nitrophenol Degradation

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1322 ◽  
Author(s):  
Thiago Martimiano do Prado ◽  
Fernando Lindo Silva ◽  
Guilherme Grosseli ◽  
Pedro Sergio Fadini ◽  
Orlando Fatibello-Filho ◽  
...  

The present work reports the degradation of 4-nitrophenol using BiVO4/CuO hybrid material synthesized by the precipitation of BiVO4 in the presence of CuO. Morphological and structural characterizations were performed using X-ray diffraction and scanning electronic microscopy coupled to energy dispersive X-ray spectroscopy. Through the calculation of the Kubelka–Munk function applied to diffuse reflectance spectrophotometry data, the hybrid material presented absorption edge of 1.85 eV. The formation of p-n heterojunction between BiVO4 and CuO renders the hybrid material suitable for the construction of a photoanode employed in hydroxyl radical generation. UV–vis spectrophotometry and high-performance liquid chromatography experiments were performed in order to monitor the degradation of 4-nitrophenol and the formation of secondary products. Additional information regarding the hybrid material was obtained through ion chromatography and total organic carbon analyses. The application of BiVO4/CuO-based photocatalyzer led to a 50.2% decrease in total organic carbon after the degradation of 4-nitrophenol. Based on the results obtained in the study, BiVO4/CuO has proved to be a promising material suitable for the removal of recalcitrant compounds in water treatment plants.

2015 ◽  
Vol 52 (1) ◽  
pp. 2-10 ◽  
Author(s):  
Lisa D. Winning ◽  
Beata Gorczyca ◽  
Kenneth Brezinski

Homes with lead service lines (LSLs) in the City of Brandon, Manitoba, Canada, were found to exceed the provincial standard of 10 μg/L for lead in drinking water. Solids identified by X-ray diffraction of LSL scale were Pb5O8 and PbO2, indicating that lead(II) solids in the LSL scale have been oxidized to lead(IV) solids by free chlorine residuals. Natural organic matter (NOM) can reduce PbO2 within a few hours, and Brandon treated water has high levels of NOM at approximately 5–7.6 mg/L as total organic carbon (TOC). As water stagnates in the LSL during periods of no water use the free chlorine residual is depleted, permitting PbO2 to oxidize NOM and be reduced to more soluble lead(II) species, resulting in an increase in dissolved lead concentrations. Although it is generally believed that aquatic humic substances (AHS) are primarily responsible for the reductant capacity of NOM, removal of AHS from the treated water resulted in a 6% decrease in lead release from PbO2, while removal of 50% of total NOM resulted in a 75% decrease in lead release. AHS and TOC were not found to play a significant role in the reduction of PbO2 in this water.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1085
Author(s):  
Patricia Castaño-Rivera ◽  
Isabel Calle-Holguín ◽  
Johanna Castaño ◽  
Gustavo Cabrera-Barjas ◽  
Karen Galvez-Garrido ◽  
...  

Organoclay nanoparticles (Cloisite® C10A, Cloisite® C15) and their combination with carbon black (N330) were studied as fillers in chloroprene/natural/butadiene rubber blends to prepare nanocomposites. The effect of filler type and load on the physical mechanical properties of nanocomposites was determined and correlated with its structure, compatibility and cure properties using Fourier Transformed Infrared (FT-IR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA) and rheometric analysis. Physical mechanical properties were improved by organoclays at 5–7 phr. Nanocomposites with organoclays exhibited a remarkable increase up to 46% in abrasion resistance. The improvement in properties was attributed to good organoclay dispersion in the rubber matrix and to the compatibility between them and the chloroprene rubber. Carbon black at a 40 phr load was not the optimal concentration to interact with organoclays. The present study confirmed that organoclays can be a reinforcing filler for high performance applications in rubber nanocomposites.


2021 ◽  
Vol 21 (11) ◽  
pp. 5592-5602
Author(s):  
Samira Almasi ◽  
Ali Mohammad Rashidi

The effect of the yttria-stabilized zirconia (YSZ) nanoparticle loading in an electro-less bath was considered as one of the vital synthesis variables for control Ni content and microstructure of prepared nanocomposite particles, which are two crucial factors to achieving high-performance SOFC anode. Nanocomposite particles were prepared using a simple electroless method without any expensive pretreatment of sensitizing by Sn2+ ions as well as activating by Pd2+ ions that are usually used to apply nickel coating on the surface of a non-conductive substrate. The process was performed by adding YSZ nanoparticles into NaOH solution, separating them from the solution by the centrifugal method, then providing several water-based nanofluids with different concentrations of activated YSZ nanoparticles, mixing them with NiCI2 solution, followed by adding the hydrazine and then NaOH solution. X-ray diffraction and scanning electron microscopy coupled with energy dispersive X-ray analysis were used to analyze the prepared nanocomposite particles. It is observed that after adding YSZ nanoparticles into the NaOH solution, the pH of the solution varied gradually from a starting pH of 10.2 to 9. Also, by increasing the YSZ nanoparticles loading in the electroless bath from 76 mg/l to 126 mg/l, the grain size of Ni deposits, the Ni content and the average size of the prepared nanocomposite particles decreased. The electrochemical mechanism previously proposed for the nickel ion reduction was modified, and a novel analytical model was proposed for variation of the efficiency of Ni deposition with YSZ nanoparticles loading.


2021 ◽  
Author(s):  
Keling Hu ◽  
Huachao Sui ◽  
Dongping Zhao

Abstract Naturally occurring nipagin and eugenol were used as the collaborative starting materials for poly(ether ester) materials. In this study, two series of nipagin and eugenol-derived copoly(ether ester)s, PHN11-xE1x and PHN11-xE2x (x = 0%, 5%, 10%, 15%, 20%), were prepared with renewable 1,6-hexanediol as a comonomer. The nipagin-derived component acts as the renewable surrogate of petroleum-based dimethyl terephthalate (DMT), while the eugenol-derived component acts as the cooperative property modifier of parent homopoly(ether ester) PHN1. 1,6-Hexanediol was chosen as the spacer because of its renewability and short chain to enhance the glass transition temperatures (Tgs) of materials. The molecular weights and chemical structures were confirmed by gel permeation chromatograph (GPC), NMR and FTIR spectroscopies. Thermal and crystalline properties were studied by thermal gravimetric analysis (TGA), differential scanning calorimetric (DSC) and wide-angle X-ray diffraction (WXRD). The tensile assays were conducted to evaluate the mechanical properties. The results suggest that properties of such kind of poly(ether ester)s can be finely tuned by the relative content of two components. Synergistic interaction of two structurally distinctive parts endows the materials with high performance.


1972 ◽  
Vol 9 (1) ◽  
pp. 117-119 ◽  
Author(s):  
Dwight A. Sangrey

A unique characteristic of many naturally cemented sensitive soils is that they are made up of finely ground fresh rock debris, "rock flour", much of which is very susceptable to chemical weathering or decomposition. Many of these minerals can be identified by X-ray diffraction. The decomposition of these minerals produces secondary products which can act as effective natural cements. A process is outlined whereby the sequence of deposition, weathering and cementation can account for the observed mechanical behaviour of naturally cemented soils.


2018 ◽  
Vol 6 (35) ◽  
pp. 17171-17176 ◽  
Author(s):  
Lasse Rabøl Jørgensen ◽  
Jiawei Zhang ◽  
Christian Bonar Zeuthen ◽  
Bo Brummerstedt Iversen

The thermal stability of the high performance n-type Te-doped Mg3Sb1.5Bi0.5 system is investigated.


Author(s):  
Wenrun Cui ◽  
Meijia Song ◽  
Guixing Jia ◽  
Yu Wang ◽  
Wanfeng Yang ◽  
...  

Abstract Tin (Sn)-based anodes have drawn extensive attention for magnesium ion batteries (MIBs) owing to their low reaction potentials, high theoretical capacities, and compatibility with conventional electrolytes. However, their poor electrochemical reactivity, sluggish kinetics, and large volume changes have obstructed progresses. Additionally, a clear understanding of the Mg storage chemistry is crucial for the development of high-performance MIBs. Here, we prepared self-supporting In-Sn alloy films with different compositions and phase constitutions via a one-step magnetron co-sputtering. As benchmarked with pure Sn film, the single-phase and biphase In-Sn alloy films effectively trigger the alloying reaction of Sn with Mg and further increasing of In significantly improves the electrochemical reactivity of the In-Sn electrodes. More importantly, operando X-ray diffraction was performed to unveil the magnesiation/demagnesiation mechanisms of the In0.2Sn0.8, In0.2Sn0.8/In3Sn and In3Sn electrodes, showing that In0.2Sn0.8 and In3Sn display different Mg storage mechanisms when existing alone or biphase coexisting. Our findings highlight the significance of the electrode design and mechanism investigations for MIBs.


2020 ◽  
Author(s):  
Yongcheng Lu ◽  
Yuanxun Li ◽  
Daming Chen ◽  
Rui Peng ◽  
Qinghui Yang ◽  
...  

Abstract In order to explore an economical functional phase alternative material for thick film resistors, the crystal structure, microstructure, and electrical properties of (1-x)LSCN + xLCNZ (x = 0.0–1.0) composite ceramics were studied through solid-state reaction experiments. The composite ceramics were characterized by x–ray diffraction, scanning electron microscopy, energy dispersive x–ray spectroscopy, and DC four–probe method. Results suggested that the main phases of LSCN and LCNZ were formed, along with a small part of impurity phases. The addition of LCNZ to LSCN decreased the electrical conductivity and changed the TCR from positive to negative. Zero TCR could be achieved around 0.6 < x < 0.8 and relatively low absolute TCR values could be obtained for the samples of 0.4 ≤ x ≤ 0.8. The ceramic of 0.6LSCN + 0.4LCNZ showed the optimal performances of conductivity = 1923 S/cm, TCR = 379.54 ppm/℃, and relative density = 95.05%.


2019 ◽  
Vol 11 (34) ◽  
pp. 30719-30727 ◽  
Author(s):  
Selvamani Vadivel ◽  
Nutthaphon Phattharasupakun ◽  
Juthaporn Wutthiprom ◽  
Salatan duangdangchote ◽  
Montree Sawangphruk

2019 ◽  
Vol 9 (4) ◽  
pp. 793 ◽  
Author(s):  
Camila Zequine ◽  
Fangzhou Wang ◽  
Xianglin Li ◽  
Deepa Guragain ◽  
S.R. Mishra ◽  
...  

The urea oxidation reaction (UOR) is a possible solution to solve the world’s energy crisis. Fuel cells have been used in the UOR to generate hydrogen with a lower potential compared to water splitting, decreasing the costs of energy production. Urea is abundantly present in agricultural waste and in industrial and human wastewater. Besides generating hydrogen, this reaction provides a pathway to eliminate urea, which is a hazard in the environment and to people’s health. In this study, nanosheets of CuCo2O4 grown on nickel foam were synthesized as an electrocatalyst for urea oxidation to generate hydrogen as a green fuel. The synthesized electrocatalyst was characterized using X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. The electroactivity of CuCo2O4 towards the oxidation of urea in alkaline solution was evaluated using electrochemical measurements. Nanosheets of CuCo2O4 grown on nickel foam required the potential of 1.36 V in 1 M KOH with 0.33 M urea to deliver a current density of 10 mA/cm2. The CuCo2O4 electrode was electrochemically stable for over 15 h of continuous measurements. The high catalytic activities for the hydrogen evolution reaction make the CuCo2O4 electrode a bifunctional catalyst and a promising electroactive material for hydrogen production. The two-electrode electrolyzer demanded a potential of 1.45 V, which was 260 mV less than that for the urea-free counterpart. Our study suggests that the CuCo2O4 electrode can be a promising material as an efficient UOR catalyst for fuel cells to generate hydrogen at a low cost.


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