scholarly journals Photocatalytic Bactericidal Efficiency of Ag Doped TiO2/Fe3O4on Fish Pathogens under Visible Light

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Ekkachai Kanchanatip ◽  
Nurak Grisdanurak ◽  
Naichia Yeh ◽  
Ta Chih Cheng
Keyword(s):  
Visible Light ◽  
Light Absorption ◽  
Band Gap Energy ◽  
Absorption Capacity ◽  
Edwardsiella Tarda ◽  
Fish Pathogens ◽  
Magnetic Photocatalyst ◽  
Visible Light Range ◽  
Photobacterium Damselae ◽  
Bactericidal Efficiency

This research evaluates photocatalytic bactericidal efficiencies of Ag-TiO2/Fe3O4in visible light using target pollutants that includeAeromonas hydrophila, Edwardsiella tarda, and Photobacterium damselaesubsp.piscicida. The investigation started with Ag-TiO2/Fe3O4synthesis and calcination followed by a series of product tests that include the examination of crystallite phase, light absorption, element composition morphology, and magnetic properties. The results of the experiment indicate that Ag and Fe3O4significantly enhanced the light absorption capacity of TiO2in the entire visible light range. The Ag-TiO2/Fe3O4prepared in this study displays significantly enhanced visible light absorption and narrowed band gap energy. The magnetic property of Ag-TiO2/Fe3O4made it easy for retrieval using a permanent magnet bar. The photocatalytic activity of Ag-TiO2/Fe3O4remains above 85% after three application cycles, which indicates high and favorable efficiency in bactericidal evaluation. The experiments have proved that the Ag-TiO2/Fe3O4magnetic photocatalyst is a promising photocatalyst for antibacterial application under visible light.

Structural reconstruction and visible-light absorption versus internal electrostatic field in two-dimensional GaN-ZnO alloys

Nanoscale ◽  
2021 ◽  
Author(s):  
Hanpu Liang ◽  
Yifeng Duan
Keyword(s):  
Visible Light ◽  
Electrostatic Field ◽  
Light Absorption ◽  
Red Shift ◽  
Two Dimensional ◽  
Visible Light Absorption ◽  
Visible Light Range ◽  
Optoelectronic Applications

GaN-ZnO alloys are more promising semiconductors than their counterparts for optoelectronic applications due to the abrupt red shift in the visible-light range. Unfortunately, the strong internal electrostatic field (IEF) seriously...

scholarly journals Synthesis and Photoactivity of Fe3O4/TiO2-Co as a Magnetically Separable Visible Light Responsive Photocatalyst

2018 ◽  
Vol 18 (3) ◽  
pp. 403 ◽  
Author(s):  
Eko Sri Kunarti ◽  
Indriana Kartini ◽  
Akhmad Syoufian ◽  
Karolina Martha Widyandari
Keyword(s):  
Methylene Blue ◽  
Visible Light ◽  
Dopant Concentration ◽  
Band Gap Energy ◽  
Methylene Blue Solution ◽  
Magnetic Photocatalyst ◽  
Blue Solution ◽  
Degradation Reaction ◽  
Visible Irradiation ◽  
Uv Visible

Synthesis of magnetic photocatalyst, Fe3O4/TiO2-Co, with characterization and photoactivity examination have been conducted. The synthesis was initiated by preparation of Fe3O4 particles using coprecipitation method. The Fe3O4 particles were then coated with TiO2-Co at a various ratio of Fe3O4:TiO2 and concentration of Co(II) dopant. The Fe3O4/TiO2-Co was characterized by FTIR, XRD, TEM, SEM-EDX, VSM, and SR UV-visible methods. Photoactivity of the Fe3O4/TiO2-Co was carried out using methylene blue as a target molecule in degradation reaction within a batch system. By using optimum conditions, the degradation of methylene blue solution was performed under exposure to UV, visible light and dark condition. Results showed that the Fe3O4/TiO2-Co formation was confirmed by the presence of Fe3O4 and anatase diffraction peaks in the X-ray diffractogram. SR UV-Vis spectra indicated that the Fe3O4/TiO2-Co was responsive to visible light. Band gap energy of the Fe3O4/TiO2-Co with dopant concentration of 1; 5; 10 and 15% were 3.22; 3.12; 3.09 and 2.81 eV, respectively. The methylene blue solution can be well photodegraded at a pH of 10 for 210 min. The Fe3O4/TiO2-Co has the highest ability to methylene blue photodegradation with dopant concentration of 10% gave degradation yield of 80.51 and 95.38% under UV and visible irradiation, respectively.

Direct Z-scheme MgIn2S4/TiO2 heterojunction for enhanced photocathodic protection of metals under visible light

2022 ◽  
Author(s):  
Hong Li ◽  
Xingqiang Cui ◽  
Weizhe Song ◽  
Zhanyuan Yang ◽  
Yanhui Li ◽  
...  
Keyword(s):  
Visible Light ◽  
Light Absorption ◽  
Separation Efficiency ◽  
Photogenerated Electron ◽  
Precursor Solution ◽  
Absorption Capacity ◽  
Photoelectric Conversion ◽  
Visible Light Absorption ◽  
Photocathodic Protection ◽  
Protection Of Metals

Abstract To improve the photocathodic protection performance of traditional TiO2 photoanodes for metals, constructing a Z-scheme heterojunction is one of the most promising and creative strategies. Herein, we fabricated a novel Z-scheme MgIn2S4 nanosheets/TiO2 nanotube nanocomposite through anodization and hydrothermal method. The optimized Z-scheme MgIn2S4/TiO2 nanocomposites exhibited stronger visible light absorption, higher separation efficiency of photoelectrons and photocathodic protection performances in comparison to pure TiO2. The theoretical analysis and experimental results show that the Z-scheme heterojunction and oxygen vacancies jointly improved the separation efficiency of photogenerated electron-hole pairs and visible light absorption capacity, thereby improving the photoelectric conversion performance of the MgIn2S4/TiO2 nanocomposites. Furthermore, the influence of the precursor solution concentration on the photocathodic protection performances of the composites was investigated. As a result, when the concentration of magnesium source in the precursor solution was 0.06 mmol, the prepared MgIn2S4/TiO2-0.06 displayed the best photocathodic protection performance. In addition, the hydroxyl radicals (•OH) generated in the electron spin resonance (ESR) experiment verified the Z-scheme heterojunction mechanism of the MgIn2S4/TiO2 composite, and also demonstrated the excellent redox performance of the composite. This work provides valuable reference for the construction of high-performance Z-scheme heterojunctions for photocathode protection of metals.

scholarly journals Surfactant-assisted microwave processing of ZnO particles: a simple way for designing the surface-to-bulk defect ratio and improving photo(electro)catalytic properties

RSC Advances ◽  
2019 ◽  
Vol 9 (30) ◽  
pp. 17165-17178 ◽  
Author(s):  
Smilja Marković ◽  
Ivana Stojković Simatović ◽  
Sanita Ahmetović ◽  
Ljiljana Veselinović ◽  
Stevan Stojadinović ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Visible Light ◽  
Microwave Synthesis ◽  
Light Absorption ◽  
Catalytic Properties ◽  
Absorption Capacity ◽  
Visible Light Absorption ◽  
Zno Particles ◽  
Electro Catalytic Activity ◽  
Surfactant Assisted

Employing CTAB in the microwave synthesis of ZnO particles enables improvement of their visible light absorption capacity and photo(electro)catalytic activity.

A novel ternary MQDs/NCDs/TiO2 nanocomposite that collaborates with activated persulfate for efficient RhB degradation under visible light irradiation

2021 ◽  
Author(s):  
Qian Zhang ◽  
Han Zhao ◽  
Yuming Dong ◽  
Xiangmiao Zhu ◽  
Xiang Liu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Absorption ◽  
Absorption Capacity ◽  
Hole Transport ◽  
Light Irradiation ◽  
Pollutant Degradation ◽  
Electron Hole ◽  
Activated Persulfate

TiO2 nanosheets modified with dual MQDs/NCD quantum dots not only promote light absorption capacity and electron–hole transport but also collaborate well with activated persulfate for pollutant degradation.

scholarly journals Synergetic Effect of In and Ag Co-Doped ZnS for Enhanced Photocatalytic Hydrogen Evolution under Visible Light Irradiation

2014 ◽  
Vol 1024 ◽  
pp. 368-371 ◽  
Author(s):  
Melody Kimi ◽  
Leny Yuliati ◽  
Mustaffa Shamsuddin
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Hydrogen Evolution ◽  
Visible Light Irradiation ◽  
Light Absorption ◽  
Synergetic Effect ◽  
Band Gap Energy ◽  
Light Irradiation ◽  
Efficient Charge ◽  
Co Doped

In and Ag co-doped ZnS photocatalysts were successfully prepared by hydrothermal method to extend the light absorption of ZnS to the visible light region. The concentration of In was constant while for Ag was varied to optimize the photocatalytic activity. The In and Ag co-doped ZnS photocatalysts showed smaller band gap energy compared to single doped In (0.1)-ZnS and undoped ZnS. The photocatalytic activity of In and Ag co-doped ZnS photocatalysts was evaluated from the amount of hydrogen produced. The hydrogen evolution rate from aqueous solution containing Na2SO3 and Na2S as sacrificial reagent under visible light irradiation obtained from In and Ag co-doped ZnS is higher compared to the single doped In (0.1)-ZnS when optimum amount of Ag dopant was added. The highest photocatalytic activity is observed for In (0.1),Ag (0.01)-ZnS with hydrogen production rate of 26.82 μmol/h. The higher performance of this photocatalyst is ascribed to the extended visible light absorption, efficient charge separation as well as improved electron transfer associated with synergistic effect of appropriate amount of In and Ag co-doped ZnS.

scholarly journals A facile synthesis of Zn-doped TiO2 nanoparticles with highly exposed (001) facets for enhanced photocatalytic performance

RSC Advances ◽  
2021 ◽  
Vol 11 (13) ◽  
pp. 7627-7632
Author(s):  
Kun Jiang ◽  
Jin Zhang ◽  
Rui Luo ◽  
Yingfei Wan ◽  
Zengjian Liu ◽  
...  
Keyword(s):  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Light Absorption ◽  
Photocatalytic Performance ◽  
Separation Efficiency ◽  
Absorption Capacity ◽  
Facile Synthesis ◽  
Visible Light Absorption ◽  
Doped Tio2 ◽  
Carrier Separation

It is a great challenge to simultaneously improve the visible light absorption capacity and enhance photon-generated carrier separation efficiency of photocatalysts.

scholarly journals Bacillus spp. Inhibit Edwardsiella tarda Quorum-Sensing and Fish Infection

Marine Drugs ◽  
2021 ◽  
Vol 19 (11) ◽  
pp. 602
Author(s):  
Rafaela A. Santos ◽  
Marta Monteiro ◽  
Fábio Rangel ◽  
Russell Jerusik ◽  
Maria J. Saavedra ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Bacterial Infections ◽  
Quorum Quenching ◽  
Bioactive Molecules ◽  
Edwardsiella Tarda ◽  
Fish Pathogens ◽  
Bacillus Spp ◽  
Photobacterium Damselae ◽  
Health Promoting ◽  
Promising Source

The disruption of pathogen communication or quorum-sensing (QS) via quorum-quenching (QQ) molecules has been proposed as a promising strategy to fight bacterial infections. Bacillus spp. have recognizable biotechnology applications, namely as probiotic health-promoting agents or as a source of natural antimicrobial molecules, including QQ molecules. This study characterized the QQ potential of 200 Bacillus spp., isolated from the gut of different aquaculture fish species, to suppress fish pathogens QS. Approximately 12% of the tested Bacillus spp. fish isolates (FI). were able to interfere with synthetic QS molecules. Ten isolates were further selected as producers of extracellular QQ-molecules and their QQ capacity was evaluated against the QS of important aquaculture bacterial pathogens, namely Aeromonas spp., Vibrio spp., Photobacterium damselae, Edwardsiela tarda, and Shigella sonnei. The results revealed that A. veronii and E. tarda produce QS molecules that are detectable by the Chr. violaceum biosensor, and which were degraded when exposed to the extracellular extracts of three FI isolates. Moreover, the same isolates, identified as B. subtilis, B. vezelensis, and B. pumilus, significantly reduced the pathogenicity of E. tarda in zebrafish larvae, increasing its survival by 50%. Taken together, these results identified three Bacillus spp. capable of extracellularly quenching aquaculture pathogen communication, and thus become a promising source of bioactive molecules for use in the biocontrol of aquaculture bacterial diseases.

The novel two-dimensional photocatalyst SnN3 with enhanced visible-light absorption for overall water splitting

Nanoscale ◽  
2019 ◽  
Vol 11 (40) ◽  
pp. 18628-18639 ◽  
Author(s):  
Shengyao Wu ◽  
Yanqing Shen ◽  
Xu Gao ◽  
Yanyan Ma ◽  
Zhongxiang Zhou
Keyword(s):  
Visible Light ◽  
Water Splitting ◽  
Light Absorption ◽  
Absorption Capacity ◽  
The Novel ◽  
Two Dimensional ◽  
Visible Light Absorption ◽  
Overall Water Splitting

SnN3 monolayer can conduct overall photocatalytic splitting of water and has ultra-high visible light absorption capacity.

Impact of Rutile Fraction on TiO2 Visible-Light Absorption and Visible-Light-Induced Photocatalytic Activity

2018 ◽  
Author(s):  
David Maria Tobaldi ◽  
Luc Lajaunie ◽  
ana caetano ◽  
nejc rozman ◽  
Maria Paula Seabra ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Light Absorption ◽  
Solid Phase ◽  
Diffraction Method ◽  
Band Alignment ◽  
Quantitative Phase Analysis ◽  
Transmission Microscopy ◽  
Visible Light Absorption ◽  
X Ray

<div>Titanium dioxide is by far the most utilised semiconductor material for photocatalytic applications. Still, it is transparent to visible-light. Recently, it has been proved that a type-II band alignment for the rutile−anatase mixture would improve its visible-light absorption.</div><div>In this research paper we thoroughly characterised the real crystalline and amorphous phases of synthesised titanias – thermally treated at different temperatures to get distinct ratios of anatase-rutile-amorphous fraction – as well as that of three commercially available photocatalytic nano-TiO2. </div><div>The structural characterisation was done via advanced X-ray diffraction method, namely the Rietveld-RIR method, to attain a full quantitative phase analysis of the specimens. The microstructure was also investigated via an advanced X-ray method, the whole powder pattern modelling. These methods were validated combining advanced aberration-corrected scanning transmission microscopy and high-resolution electron energy-loss spectroscopy. The photocatalytic activity was assessed in the liquid- and gas-solid phase (employing rhodamine B and 4-chlorophenol, and isopropanol, respectively, as the organic substances to degrade) using a light source irradiating exclusively in the visible-range.</div><div>Optical spectroscopy showed that even a small fraction of rutile (2 wt%) is able to shift to lower energies the apparent optical band gap of an anatase-rutile mixed phase. But is this enough to attain a real photocatalytic activity promoted by merely visible-light?</div><div>We tried to give a reply to that question.</div><div>Photocatalytic activity results in the liquid-solid phase showed that a high surface hydroxylation led to specimen with superior visible light-induced catalytic activity (i.e. dye and ligand-to-metal charge transfer complexes sensitisation effects). That is: not photocatalysis <i>sensu-strictu</i>.</div><div>On the other hand, the gas-solid phase results showed that a higher amount of the rutile fraction (around 10 wt%), together with less recombination of the charge carriers, were more effective for an actual photocatalytic oxidation of isopropanol.</div>

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