scholarly journals LignoPhot: Photoactive Hybrid lignin/Bi4O5Br2/BiOBr Composite for Complex Pollutants Removal

2021 ◽  
Author(s):  
Tetyana Budnyak ◽  
Joy Onwumere ◽  
Ievgen V. Pylypchuk ◽  
Aleksander Jaworski ◽  
Jianhong Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Metal Ions ◽  
Photoelectron Spectroscopy ◽  
Organic Dyes ◽  
Dye Degradation ◽  
Low Cost ◽  
Resonance Spectroscopy ◽  
Hydrolysis Lignin ◽  
X Ray ◽  
Main Component

Valorization of lignin is still an open question and lignin has therefore remained an underutilized biomaterial. This situation is even more pronounced for hydrolysis lignin, which is characterized by a highly condensed and excessively cross-linked structure. We report on photoactive lignin/Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>/BiOBr bio-inorganic composites consisting of a lignin substrate that is coated by Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>/BiOBr nanosheet photocatalysts. The structure of the hybrid material was investigated by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy including energy dispersive X-ray (EDX) spectroscopy, and solid state <sup>1</sup>H−<sup>13</sup>C nuclear magnetic resonance spectroscopy (<sup>1</sup>H−<sup>13</sup>C NMR). The material contains 18.9% of Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>/BiOBr and was found to be effective for the photocatalytic degradation of cationic methylene blue (MB) and zwitterionic rhodamine B (RhB) dyes under irradiation with 405 nm light. Lignin/Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>/BiOBr was able to decrease the dye concentration from 80 mg·L<sup>–1</sup> to 12.3 mg·L<sup>–1</sup> for RhB (85%) and from 80 mg·L<sup>–1</sup> to 4.4 mg·L<sup>–1</sup> for MB (95%). Complementary to the dye degradation, the lignin as a main component of the composite, was found to be efficient and rapid biosorbent for metal ions in aqueous solutions. The highest adsorption capacity was found after 2 hours of phases contact and reached 0.45 mmol·g<sup>–1 </sup>for Ni(II) ions (neutral media). The low cost, simplicity of the synthesis, good stability and ability to simultaneously photooxidize organic dyes and to adsorb metal ions, make the developed photoactive lignin/Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>/BiOBr composite a prospective material for textile wastewaters remediation

scholarly journals LignoPhot: Photoactive Hybrid lignin/Bi4O5Br2/BiOBr Composite for Complex Pollutants Removal

2021 ◽  
Author(s):  
Tetyana Budnyak ◽  
Joy Onwumere ◽  
Ievgen V. Pylypchuk ◽  
Aleksander Jaworski ◽  
Jianhong Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Metal Ions ◽  
Photoelectron Spectroscopy ◽  
Organic Dyes ◽  
Dye Degradation ◽  
Low Cost ◽  
Resonance Spectroscopy ◽  
Hydrolysis Lignin ◽  
X Ray ◽  
Main Component

Valorization of lignin is still an open question and lignin has therefore remained an underutilized biomaterial. This situation is even more pronounced for hydrolysis lignin, which is characterized by a highly condensed and excessively cross-linked structure. We report on photoactive lignin/Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>/BiOBr bio-inorganic composites consisting of a lignin substrate that is coated by Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>/BiOBr nanosheet photocatalysts. The structure of the hybrid material was investigated by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy including energy dispersive X-ray (EDX) spectroscopy, and solid state <sup>1</sup>H−<sup>13</sup>C nuclear magnetic resonance spectroscopy (<sup>1</sup>H−<sup>13</sup>C NMR). The material contains 18.9% of Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>/BiOBr and was found to be effective for the photocatalytic degradation of cationic methylene blue (MB) and zwitterionic rhodamine B (RhB) dyes under irradiation with 405 nm light. Lignin/Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>/BiOBr was able to decrease the dye concentration from 80 mg·L<sup>–1</sup> to 12.3 mg·L<sup>–1</sup> for RhB (85%) and from 80 mg·L<sup>–1</sup> to 4.4 mg·L<sup>–1</sup> for MB (95%). Complementary to the dye degradation, the lignin as a main component of the composite, was found to be efficient and rapid biosorbent for metal ions in aqueous solutions. The highest adsorption capacity was found after 2 hours of phases contact and reached 0.45 mmol·g<sup>–1 </sup>for Ni(II) ions (neutral media). The low cost, simplicity of the synthesis, good stability and ability to simultaneously photooxidize organic dyes and to adsorb metal ions, make the developed photoactive lignin/Bi<sub>4</sub>O<sub>5</sub>Br<sub>2</sub>/BiOBr composite a prospective material for textile wastewaters remediation

scholarly journals Microwave-assisted preparation of ZnS and ZnSe nanocrystals with different morphologies for photodegradation process of organic dyes

2019 ◽  
Author(s):  
Katarzyna Matras-Postolek ◽  
A. Zaba ◽  
S. Sovinska ◽  
D. Bogdal
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Organic Dyes ◽  
Zinc Sulphide ◽  
Conventional Heating ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy

Zinc sulphide (ZnS) and zinc selenide (ZnSe) and manganese-doped and un-doped with different morphologies from 1D do 3D microflowers were successfully fabricated in only a few minutes by solvothermal reactions under microwave irradiation. In order to compare the effect of microwave heating on the properties of obtained  nanocrystals, additionally the synthesis under conventional heating was conducted additionally in similar conditions. The obtained nanocrystals were systematically characterized in terms of structural and optical properties using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance UV-Vis spectroscopy (DR UV-Vis), Fourier-transform infrared spectroscopy (FT-IR), photoluminescence spectroscopy (PL), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) surface area analysis. The photocatalytic activity of ZnSe, ZnS, ZnS:Mn and ZnSe:Mn nanocrystals with different morphologies was evaluated by the degradation of methyl orange (MO) and Rhodamine 6G (R6G), respectively. The results show that Mn doped NCs samples had higher coefficient of degradation of organic dyes under ultraviolet irradiation (UV).

scholarly journals Synthesis of Hollow Flower-Like Fe3O4/MnO2/Mn3O4 Magnetically Separable Microspheres with Valence Heterostructure for Dye Degradation

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 589 ◽  
Author(s):  
Mingliang Ma ◽  
Yuying Yang ◽  
Yan Chen ◽  
Fei Wu ◽  
Wenting Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Organic Contaminants ◽  
Dye Degradation ◽  
Catalytic Performance ◽  
X Ray ◽  
Composite Microspheres ◽  
Magnetically Separable ◽  
Mno2 Nanosheet

In this manuscript, hollow flower-like ferric oxide/manganese dioxide/trimanganese tetraoxide (Fe3O4/MnO2/Mn3O4) magnetically separable microspheres were prepared by combining a simple hydrothermal method and reduction method. As the MnO2 nanoflower working as precursor was partially reduced, Mn3O4 nanoparticles were in situ grown from the MnO2 nanosheet. The composite microspheres were characterized in detail by employing scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), vibration sample magnetometer (VSM) and UV–visible spectrophotometer (UV–vis). Under visible light conditions, the test for degrading rhodamine B (RhB) was used to verify the photocatalytic activity of the photocatalyst. The results showed that the efficiency of the Fe3O4/MnO2/Mn3O4 photocatalyst in visible light for 130 min is 94.5%. The catalytic activity of photocatalyst far exceeded that of the Fe3O4/MnO2 component, and after four cycles, the catalytic performance of the catalyst remained at 78.4%. The superior properties of the photocatalyst came from improved surface area, enhanced light absorption, and efficient charge separation of the MnO2/Mn3O4 heterostructure. This study constructed a green and efficient valence heterostructure composite that created a promising photocatalyst for degrading organic contaminants in aqueous environments.

scholarly journals Biosynthesized Highly Stable Au/C Nanodots: Ideal Probes for the Selective and Sensitive Detection of Hg2+ Ions

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 245 ◽  
Author(s):  
Sada Venkateswarlu ◽  
Saravanan Govindaraju ◽  
Roopkumar Sangubotla ◽  
Jongsung Kim ◽  
Min-Ho Lee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Metal Ions ◽  
Fluorescent Probe ◽  
Photoelectron Spectroscopy ◽  
Industrial Development ◽  
Carbon Nanodots ◽  
Detection Mechanism ◽  
X Ray ◽  
Transmission Electron

The enormous ongoing industrial development has caused serious water pollution which has become a major crisis, particularly in developing countries. Among the various water pollutants, non-biodegradable heavy metal ions are the most prevalent. Thus, trace-level detection of these metal ions using a simple technique is essential. To address this issue, we have developed a fluorescent probe of Au/C nanodots (GCNDs-gold carbon nanodots) using an eco-friendly method based on an extract from waste onion leaves (Allium cepa-red onions). The leaves are rich in many flavonoids, playing a vital role in the formation of GCNDs. Transmission electron microscopy (TEM) and Scanning transmission electron microscopy-Energy-dispersive X-ray spectroscopy (STEM-EDS) elemental mapping clearly indicated that the newly synthesized materials are approximately 2 nm in size. The resulting GCNDs exhibited a strong orange fluorescence with excitation at 380 nm and emission at 610 nm. The GCNDs were applied as a fluorescent probe for the detection of Hg2+ ions. They can detect ultra-trace concentrations of Hg2+ with a detection limit of 1.3 nM. The X-ray photoelectron spectroscopy results facilitated the identification of a clear detection mechanism. We also used the new probe on a real river water sample. The newly developed sensor is highly stable with a strong fluorescent property and can be used for various applications such as in catalysis and biomedicine.

Photocatalytic Oxidation of Alcohols Over Magnetically Recoverable Gold Supported Iron Oxide Nanoparticles

2019 ◽  
Vol 11 (12) ◽  
pp. 1731-1738 ◽  
Author(s):  
Ma Hui ◽  
Wu Juzhen ◽  
Zhao Li ◽  
Zhou Zheng ◽  
Guo Jiahu
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Photocatalytic Oxidation ◽  
Organic Dyes ◽  
Atomic Emission ◽  
One Pot ◽  
X Ray ◽  
Inductively Coupled ◽  
Oxidation Of Alcohols

A one-pot simple and efficient synthetic route for the synthesis of Au-loaded Fe2O3 nanoparticles was developed, and this material's photocatalytic activity for visible light assisted oxidation of alcohols and degradation of organic dye were studied. As-synthesized nanostructured catalyst was characterised by powder X-ray diffraction (XRD), transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), SEM-mapping, X-ray photoelectron spectroscopy (XPS), N2 adsorption–desorption isotherm (BET), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). It was observed that 5–10 nm Au-nanoparticles supported on 10–80 nm Fe2O3 shows boomerang-shaped nanoparticle. Gold loading of 1 wt% shows high conversion and selectivity towards the target product aldehyde. The synthesized nanomaterial also proved to be an excellent photocatalyst for degradation of organic dyes such as methylene blue (MB) and rhodamine B (RhB). The catalyst proved to be noteworthy as it does not loss in its catalytic activity even after five cycles of reuse.

scholarly journals Synergistically homogeneous-heterogeneous Fenton catalysis of trace copper ion and g-C3N4 for degradation of organic pollutants

2021 ◽  
Author(s):  
Z. Y. Yao ◽  
G. X. Zhu ◽  
T. L. Lu ◽  
Y. Z. Zhan
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Metal Ions ◽  
Photoelectron Spectroscopy ◽  
Organic Pollutant ◽  
Copper Ion ◽  
Heterogeneous Fenton ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Synergistic Catalysis

Abstract Using the bulk g-C3N4 as a precursor, four g-C3N4 nanosheets were further prepared by ultrasonic, thermal, acid, and alkali exfoliation. The structures of these materials were characterized by various techniques such as X-ray powder diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-Ray spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The synergistical Fenton catalysis of these materials with Cu2+ was evaluated by using rhodamine B as a simulated organic pollutant. The results showed that there existed a significant synergistical Fenton catalysis between Cu2+ and g-C3N4. This synergistic effect can be observed even when the concentration of Cu2+ was as low as 0.064 mg L−1. The properties of g-C3N4 strongly influenced the catalytic activity of the Cu2+/g-C3N4 system. The coexistent of Cu2+ and the alkali exfoliated g-C3N4 showed the most excellent catalytic activity. Hydroxyl radicals as oxidizing species were confirmed in the Cu2+/g-C3N4 system by electron paramagnetic resonance spectrum. The synergistic catalysis may be attributed to the easier reduction of Cu2+ adsorbed on the g-C3N4. This study provided an excellent Fenton catalytic system, and partly solved the rapid deactivation of heterogeneous Fenton catalysts caused by the leaching of metal ions. HIGHTLIGHTS There exists a significant synergistical Fenton catalysis between trace Cu2+ and g-C3N4. The Cu2+ concentration is lower than the maximum acceptable limit in drinking water. This study partly solved the rapid deactivation caused by the leaching of metal ions. This study reminds researchers to pay attention to the possible synergistic catalysis between leached ions and supports.

scholarly journals Visible Light-Driven Mn-MoS2/rGO Composite Photocatalysts for the Photocatalytic Degradation of Rhodamine B

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Thi Thuy Trang Phan ◽  
Thanh Tam Truong ◽  
Ha Tran Huu ◽  
Le Tuan Nguyen ◽  
Van Thang Nguyen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Rhodamine B ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Composite Photocatalysts

The n%Mn-MoS2/rGO (labeled as n%MMS/rGO, where n% = Mn/(Mn + Mo) in mol) composites were successfully prepared by a facile hydrothermal method from the Mn-MoS2 (MMS) and rGO precursors, in which the MMS was obtained by a facile one-step calcination of (NH4)6Mo7O24·4H2O, (NH2)2CS, and Mn(CH3COO)2·4H2O as precursors in N2 gas at 650°C. The samples were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron paramagnetic resonance spectroscopy (EPR), UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), and X-ray photoelectron spectroscopy (XPS), which indicates the composites containing nanosheets of Mn-MoS2 and rGO components. The photocatalytic activities of the n%MMS/rGO composite photocatalysts were evaluated through the photodegradation of rhodamine B (RhB) under the visible light irradiation. The enhancement in the photocatalytic performance of the achieved composites was attributed to the synergic effect of Mn doping and rGO matrix. The investigation of photocatalytic mechanism was also conducted.

scholarly journals Incorporating N Atoms into SnO2 Nanostructure as an Approach to Enhance Gas Sensing Property for Acetone

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 445 ◽  
Author(s):  
Xiangfeng Guan ◽  
Yongjing Wang ◽  
Peihui Luo ◽  
Yunlong Yu ◽  
Dagui Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gas Sensor ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Gas Sensing ◽  
Diffuse Reflectance Spectroscopy ◽  
Limit Of Detection ◽  
Low Cost ◽  
X Ray ◽  
Sno2 Nanostructure

The development of high-performance acetone gas sensor is of great significance for environmental protection and personal safety. SnO2 has been intensively applied in chemical sensing areas, because of its low cost, high mobility of electrons, and good chemical stability. Herein, we incorporated nitrogen atoms into the SnO2 nanostructure by simple solvothermal and subsequent calcination to improve gas sensing property for acetone. The crystallization, morphology, element composition, and microstructure of as-prepared products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Electron paramagnetic resonance (EPR), Raman spectroscopy, UV–visible diffuse reflectance spectroscopy (UV–vis DRS), and the Brunauer–Emmett–Teller (BET) method. It has been found that N-incorporating resulted in decreased crystallite size, reduced band-gap width, increased surface oxygen vacancies, enlarged surface area, and narrowed pore size distribution. When evaluated as gas sensor, nitrogen-incorporated SnO2 nanostructure exhibited excellent sensitivity for acetone gas at the optimal operating temperature of 300 °C with high sensor response (Rair/Rgas − 1 = 357) and low limit of detection (7 ppb). The nitrogen-incorporated SnO2 gas sensor shows a good selectivity to acetone in the interfering gases of benzene, toluene, ethylbenzene, hydrogen, and methane. Furthermore, the possible gas-sensing mechanism of N-incorporated SnO2 toward acetone has been carefully discussed.

ZnS NANOFLOWERS ON GRAPHENE FOR USE AS A HIGH-PERFORMANCE PHOTOCATALYST

NANO ◽  
2014 ◽  
Vol 09 (08) ◽  
pp. 1450097 ◽  
Author(s):  
ZENG BIN ◽  
LONG HUI
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Dye Degradation ◽  
Uv Light ◽  
Xps Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Photocatalytic Activities ◽  
Potential Applications

The nanocomposites of graphene loaded– ZnS nanoflowers (GR– ZnS ) had been successfully prepared. Materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectra (FTIR), photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS) spectra. A possible formation mechanism of this architecture was proposed. The experimental results revealed that these nanoflowers exhibited excellent UV-light photocatalytic activities for pollutant methyl orange (MO) dye degradation. These new nanostructures were expected to show considerable potential applications in the water treatment.

scholarly journals Three-dimensional Co 3 O 4 @MWNTs nanocomposite with enhanced electrochemical performance for nonenzymatic glucose biosensors and biofuel cells

2017 ◽  
Vol 4 (12) ◽  
pp. 170991 ◽  
Author(s):  
Kailong Jiao ◽  
Yu Jiang ◽  
Zepeng Kang ◽  
Ruiyun Peng ◽  
Shuqiang Jiao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Glucose Oxidation ◽  
Low Cost ◽  
Three Dimensional ◽  
Open Circuit ◽  
Strongly Coupled ◽  
X Ray ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Three-dimensional nanoarchitectures of Co 3 O 4 @multi-walled carbon nanotubes (Co 3 O 4 @MWNTs) were synthesized via a one-step process with hydrothermal growth of Co 3 O 4 nanoparticles onto MWNTs. The structure and morphology of the Co 3 O 4 @MWNTs were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller, scanning electron microscopy and transmission electron microscopy. The electrocatalytic mechanism of the Co 3 O 4 @MWNTs was studied by X-ray photoelectron spectroscopy and cyclic voltammetry. Co 3 O 4 @MWNTs exhibited high electrocatalytic activity towards glucose oxidation in alkaline medium and could be used in nonenzymatic electrochemical devices for glucose oxidation. The open circuit voltage of the nonenzymatic glucose/O 2 fuel cell was 0.68 V, with a maximum power density of 0.22 mW cm −2 at 0.30 V. The excellent electrochemical properties, low cost, and facile preparation of Co 3 O 4 @MWNTs demonstrate the potential of strongly coupled oxide/nanocarbon hybrid as effective electrocatalyst in glucose fuel cells and biosensors.

Sign in / Sign up

Export Citation Format

Share Document