Enhanced Antibacterial Photocatalytic Activity of Porous Few-Layer C3N4

2020 ◽  
Vol 20 (9) ◽  
pp. 5944-5950 ◽  
Author(s):  
Guoxin Song ◽  
Longwei Wang ◽  
Ruiqi Yang ◽  
Yanchen Ji ◽  
Ruitong Zhang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Hydroxyl Radicals ◽  
Removal Rate ◽  
Low Cost ◽  
Disinfection Byproducts ◽  
Oxygen Species ◽  
Positive Bacterium ◽  
Surface Areas ◽  
Good Biocompatibility ◽  
Excellent Stability

Nowadays, antibacterial photocatalytic activity of semiconductors has attracted great attention due to its excellent stability, good biocompatibility and no disinfection byproducts. Herein, a porous few-layer C3N4 was successfully fabricated via a simple and low-cost bottom-up method. The asprepared porous few-layer C3N4 exhibits large specific surface areas, which is about 4.8 times than bulk C3N4. Under the light (<430 nm) irradiation, reactive oxygen species (ROS) (singlet oxygen (1O2), hydroxyl radicals (·OH), and superoxide (O·−2)) can be generated. The porous few-layer C3N4 was used as an antibacterial agent to kill gram-positive bacterium S. Aureus with an anibacterial efficiency up to 99.7%. The log removal rate of the porous few-layer C3N4 is more than 50 times than the bulk C3N4. The material shows a potential application in water purification and antibacterial photocatalytic therapy.

scholarly journals Low-Cost Synthesis of Cu-Modified Immobilized Nanoporous TiO2 for Photocatalytic Degradation of 1H-Benzotriazole

Catalysts ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 19 ◽  
Author(s):  
Tihana Čižmar ◽  
Ivana Panžić ◽  
Krešimir Salamon ◽  
Ivana Grčić ◽  
Lucija Radetić ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Spin Coating ◽  
Low Cost ◽  
Electrochemical Anodization ◽  
Synthesis Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Areas ◽  
Titanium Foils ◽  
The Given

Cu-modified immobilized nanoporous TiO2 photocatalysts, prepared by electrochemical anodization of titanium foils, were obtained via four different synthesis methods: hydrothermal synthesis, anodization with Cu source, electrodeposition, and spin-coating, using two different copper sources, Cu(NO3)2 and Cu(acac)2. The objective of this research was to investigate how copper modifications can improve the photocatalytic activity of immobilized nanoporous TiO2 under the UV/solar light irradiation. The best photocatalytic performances were obtained for Cu-modifications using spin-coating. Therefore, the effect of irradiated catalyst surface areas on the adsorption of model pollutants, methylene blue (MB) and 1H-benzotriazole (BT), was examined for samples with Cu-modification by the spin-coating technique. The mechanisms responsible for increased degradation of MB and BT at high Cu concentrations (0.25 M and 0.5 M) and decreased degradation at low Cu loadings (0.0625 M and 0.125 M) were explained. 1H-benzotriazole was used to study the photocatalytic activity of the given samples because it is highly toxic and present in most water systems. The characterization of the synthesized Cu-modified photocatalysts in terms of phase composition, crystal structure, and morphology were investigated using X-ray Diffraction, Raman Spectroscopy, Scanning Electron Microscopy, and Energy Dispersive X-ray spectroscopy.

Three-dimensionally Hierarchical Bi2WO6 Architectures with Enhanced Photocatalytic Activity

NANO ◽  
2016 ◽  
Vol 11 (12) ◽  
pp. 1650135 ◽  
Author(s):  
Tianhua Chen ◽  
Hongbing Lu ◽  
Jinniu Zhang ◽  
Jianzhi Gao ◽  
Feng Yin ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Rhodamine B ◽  
Photocatalytic Performance ◽  
Ph Value ◽  
Precursor Solution ◽  
Structural Features ◽  
Oxygen Species ◽  
Surface Areas ◽  
Specific Surface Areas

Three-dimensionally hierarchical Bi2WO6 architectures have been produced via a facile and economical hydrothermal method without any template or surfactant. This architecture with flower-like morphology is assembled by numbers of intercrossed nanosheets. Moreover, different Bi2WO6 nanostructures including multilayered disks and irregular nanoplates can also be produced by simply adjusting the pH value of the precursor solution. Importantly, this kind of hierarchically structured Bi2WO6 architecture exhibits a much better photocatalytic activity in the photodegradation of rhodamine B than that of conventional Bi2WO6 multilayered disks and nanoplates. This enhanced photocatalytic performance is mainly attributed to the large specific surface areas, special structural features and high capability of absorbed oxygen species. The present work offers an effective approach for the further improvement of photocatalytic activity by designing a desirable micro/nanoarchitecture.

scholarly journals Effective Photocatalytic Activity of Sulfate-Modified BiVO4 for the Decomposition of Methylene Blue Under LED Visible Light

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2681 ◽  
Author(s):  
Vinh Huu Nguyen ◽  
Quynh Thi Phuong Bui ◽  
Dai-Viet N. Vo ◽  
Kwon Taek Lim ◽  
Long Giang Bach ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Hydroxyl Radicals ◽  
High Efficiency ◽  
Separation Efficiency ◽  
Diffuse Reflectance Spectroscopy ◽  
Removal Rate ◽  
Gravimetric Analysis ◽  
X Ray

In this study, we investigated sulfate-modified BiVO4 with the high photocatalytic activity synthesized by a sol-gel method in the presence of thiourea, followed by the annealing process at different temperatures. Its structure was characterized by thermal gravimetric analysis (TGA), powder X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). The BiVO4 synthesized in the presence of thiourea and calcined at 600 °C (T-BVO-600) exhibited the highest photocatalytic degradation efficiency of methylene blue (MB) in water; 98.53% MB removal was achieved within 240 min. The reaction mechanisms that affect MB photocatalytic degradation on the T-BVO-600 were investigated via an indirect chemical probe method, using chemical agents to capture the active species produced during the early stages of photocatalysis, including 1,4-benzoquinone (scavenger for O2−), ethylenediaminetetraacetic acid disodium salt (scavenger for h+), and tert-butanol (scavenger for HO•). The results show that holes (h+) and hydroxyl radicals (HO•) are the dominant species of MB decomposition. Photoluminescence (PL) measurement results of terephthalic acid solutions in the presence of BiVO4 samples and BiVO4 powders confirm the involvement of hydroxyl radicals and the separation efficiency of electron-hole pairs in MB photocatalytic degradation. Besides, the T-BVO-600 exhibits good recyclability for MB removal, achieving a removal rate of above 83% after five cycles. The T-BVO-600 has the features of high efficiency and good recyclability for MB photocatalytic degradation. These results provide new insight into the purpose of improving the photocatalytic activity of BiVO4 catalyst.

scholarly journals A simple approach to prepare fluorescent molecularly imprinted nanoparticles

RSC Advances ◽  
2021 ◽  
Vol 11 (13) ◽  
pp. 7732-7737
Author(s):  
Fenying Wang ◽  
Dan Wang ◽  
Tingting Wang ◽  
Yu Jin ◽  
Baoping Ling ◽  
...  
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Sol Gel ◽  
Silica Sol ◽  
Simple Approach ◽  
Imprinted Polymer ◽  
Molecularly Imprinted ◽  
Low Toxicity ◽  
Good Biocompatibility ◽  
Molecularly Imprinted Nanoparticles

Fluorescent molecularly imprinted polymer (FMIP) gains great attention in many fields due to their low cost, good biocompatibility and low toxicity. Here, a high-performance FMIP was prepared based on the autocatalytic silica sol–gel reaction.

scholarly journals Vanadium doped CaTiO3 cuboids: Role of vanadium in improving the photocatalytic activity

2021 ◽  
Author(s):  
Harsha Bantawal ◽  
Sandhya U. Shenoy ◽  
Denthaje Krishna Bhat
Keyword(s):  
Photocatalytic Activity ◽  
Water Splitting ◽  
Dye Degradation ◽  
Low Cost ◽  
Physicochemical Stability ◽  
Photocatalytic Dye Degradation

CaTiO3 has attracted enormous interest in the field of photocatalytic dye degradation and water splitting owing to its low cost, excellent physicochemical stability and structural tunability. Herein, we have developed...

scholarly journals Shape Effects of Ceria Nanoparticles on the Water‒Gas Shift Performance of CuOx/CeO2 Catalysts

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 753
Author(s):  
Maria Lykaki ◽  
Sofia Stefa ◽  
Sónia A. C. Carabineiro ◽  
Miguel A. Soria ◽  
Luís M. Madeira ◽  
...  
Keyword(s):  
Low Cost ◽  
Catalytic Performance ◽  
Fine Tuning ◽  
Water Gas Shift ◽  
Oxygen Species ◽  
Ceria Nanoparticles ◽  
Ceo2 Sample ◽  
Equilibrium Conversion ◽  
Shape Effects ◽  
Water Gas

The copper–ceria (CuOx/CeO2) system has been extensively investigated in several catalytic processes, given its distinctive properties and considerable low cost compared to noble metal-based catalysts. The fine-tuning of key parameters, e.g., the particle size and shape of individual counterparts, can significantly affect the physicochemical properties and subsequently the catalytic performance of the binary oxide. To this end, the present work focuses on the morphology effects of ceria nanoparticles, i.e., nanopolyhedra (P), nanocubes (C), and nanorods (R), on the water–gas shift (WGS) performance of CuOx/CeO2 catalysts. Various characterization techniques were employed to unveil the effect of shape on the structural, redox and surface properties. According to the acquired results, the support morphology affects to a different extent the reducibility and mobility of oxygen species, following the trend: R > P > C. This consequently influences copper–ceria interactions and the stabilization of partially reduced copper species (Cu+) through the Cu2+/Cu+ and Ce4+/Ce3+ redox cycles. Regarding the WGS performance, bare ceria supports exhibit no activity, while the addition of copper to the different ceria nanostructures alters significantly this behaviour. The CuOx/CeO2 sample of rod-like morphology demonstrates the best catalytic activity and stability, approaching the thermodynamic equilibrium conversion at 350 °C. The greater abundance in loosely bound oxygen species, oxygen vacancies and highly dispersed Cu+ species can be mainly accounted for its superior catalytic performance.

scholarly journals Preparation and Characterization of High-Efficiency Magnetic Heavy Metal Capture Flocculants

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1732
Author(s):  
Yuanyuan Yu ◽  
Yongjun Sun ◽  
Jun Zhou ◽  
Aowen Chen ◽  
Kinjal J. Shah
Keyword(s):  
Heavy Metal ◽  
Reaction Time ◽  
High Efficiency ◽  
Removal Rate ◽  
Low Cost ◽  
Monomer Concentration ◽  
Synthesis Process ◽  
Response Surface Optimization ◽  
Metal Capture ◽  
Total Monomer Concentration

In this study, a high-efficiency magnetic heavy metal flocculant MF@AA was prepared based on carboxymethyl chitosan and magnetic Fe3O4. It was characterized by SEM, FTIR, XPS, XRD and VSM, and the Cu(II) removal rate was used as the evaluation basis for the preparation process. The effects of AMPS content, total monomer concentration, photoinitiator concentration and reaction time on the performance of MF@AA flocculation to remove Cu(II) were studied. The characterization results show that MF@AA has been successfully prepared and exhibits good magnetic induction characteristics. The synthesis results show that under the conditions of 10% AMPS content, 35% total monomer concentration, 0.04% photoinitiator concentration, and 1.5 h reaction time, the best yield of MF@AA is 77.69%. The best removal rate is 87.65%. In addition, the response surface optimization of the synthesis process of MF@AA was performed. The optimal synthesis ratio was finally determined as iron content 6.5%, CMFS: 29.5%, AM: 53.9%, AMPS: 10.1%. High-efficiency magnetic heavy metal flocculant MF@AA shows excellent flocculation performance in removing Cu(II). This research provides guidance and ideas for the development of efficient and low-cost flocculation technology to remove Cu(II) in wastewater.

P-doped CdS integrated with multiphasic MoSe2 nanosheets accomplishing prominent photocatalytic activity for hydrogen evolution

2021 ◽  
Author(s):  
Xuanxuan Yang ◽  
Hong Yang ◽  
Tiantian Zhang ◽  
Yongbing Lou ◽  
Jinxi Chen
Keyword(s):  
Photocatalytic Activity ◽  
Transition Metal ◽  
Hydrogen Evolution ◽  
Low Cost ◽  
Cds Nanorods

Rational modulation of low-cost and versatile Cd-based photocatalysts coupled with transition metal diselenides is favorable to reinforcing the performance of hydrogen evolution. Herein, the P-doped CdS nanorods (denoted as PCS)...

scholarly journals Encapsulate α-MnO2 nanofiber within graphene layer to tune surface electronic structure for efficient ozone decomposition

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guoxiang Zhu ◽  
Wei Zhu ◽  
Yang Lou ◽  
Jun Ma ◽  
Wenqing Yao ◽  
...  
Keyword(s):  
Graphene Layer ◽  
Water Resistance ◽  
Catalyst Design ◽  
Ozone Decomposition ◽  
Oxygen Species ◽  
Ozone Molecule ◽  
Practical Application ◽  
Surface Electronic Structure ◽  
Reaction Barriers ◽  
Excellent Stability

AbstractMajor challenges encountered when developing manganese-based materials for ozone decomposition are related to the low stability and water inactivation. To solve these problems, a hierarchical structure consisted of graphene encapsulating α-MnO2 nanofiber was developed. The optimized catalyst exhibited a stable ozone conversion efficiency of 80% and excellent stability over 100 h under a relative humidity (RH) of 20%. Even though the RH increased to 50%, the ozone conversion also reached 70%, well beyond the performance of α-MnO2 nanofiber. Here, surface graphite carbon was activated by capturing the electron from inner unsaturated Mn atoms. The excellent stability originated from the moderate local work function, which compromised the reaction barriers in the adsorption of ozone molecule and the desorption of the intermediate oxygen species. The hydrophobic graphene shells hindered the chemisorption of water vapour, consequently enhanced its water resistance. This work offered insights for catalyst design and would promote the practical application of manganese-based catalysts in ozone decomposition.

scholarly journals Enhanced sunlight photocatalytic activity and biosafety of marine-driven synthesized cerium oxide nanoparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Somayeh Safat ◽  
Foad Buazar ◽  
Salim Albukhaty ◽  
Soheila Matroodi
Keyword(s):  
Photocatalytic Activity ◽  
Band Gap ◽  
Color Change ◽  
Removal Rate ◽  
Average Crystallite Size ◽  
Face Centered Cubic ◽  
One Pot ◽  
Stabilizing Agents ◽  
Face Centered ◽  
Living Organisms

AbstractThis contribution presents the biosynthesis, physiochemical properties, toxicity and photocatalytic activity of biogenic CeO2 NPs using, for the first time, marine oyster extract as an effective and rich source of bioreducing and capping/stabilizing agents in a one-pot recipe. CeO2 NPs formation was initially confirmed through the color change from light green to pale yellow and subsequently, their corresponding absorption peak was spectroscopically determined at 310 nm with an optical band-gap of 4.67 eV using the DR-UV technique. Further, XRD and Raman analyses indicated that nanoceria possessed face-centered cubic arrangements without any impurities, having an average crystallite size of 10 nm. TEM and SEM results revealed that biogenic CeO2 NPs was approximately spherical in shape with a median particle size of 15 ± 1 nm. The presence of various bioorganic substances on the surface of nanoparticles was deduced by FTIR and TGA results. It is found that marine-based nanoceria shows no cytotoxic effect on the normal cell, thus indicating their enhanced biocompatibility and biosafety to living organisms. Environmentally, due to energy band gap, visible light-activated CeO2 nanocatalyst revealed superior photocatalytic performance on degradation of methylene blue pollutant with removal rate of 99%. Owing to the simplicity, cost-effectiveness, and environmentally friendly nature, this novel marine biosynthetic route paves the way for prospective applications of nanoparticles in various areas.

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