scholarly journals Solid-State Synthesis of Direct Z-Scheme Cu2O/WO3 Nanocomposites with Enhanced Visible-Light Photocatalytic Performance

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 293
Author(s):  
Hassan Ali ◽  
Ali Guler ◽  
Milan Masar ◽  
Pavel Urbanek ◽  
Michal Urbanek ◽  
...  
Keyword(s):  
Solid State ◽  
Visible Light ◽  
Photocatalytic Performance ◽  
Light Emitting Diode ◽  
Scanning Calorimetry ◽  
Light Emitting ◽  
Low Concentrations ◽  
Vis Spectroscopy ◽  
Visible Light Active ◽  
Cu2o Nanoparticles

In this paper, we report the preparation of visible-light active direct Z-scheme Cu2O/WO3 nanocomposite photocatalyst by a solid-state reaction avoiding the otherwise inevitable formation of CuWO4 phase in wet syntheses. Structure, morphology, and thermal and optical properties of prepared WO3 nanoplatelets decorated by Cu2O were investigated by XRD, Raman spectroscopy, SEM/TEM, combined thermogravimetric (TG)/differential scanning calorimetry (DSC) analysis, and UV–VIS spectroscopy. The photocatalytic performance of the prepared samples under UV and visible light was studied through monitoring discoloration of methylene blue under illumination by selected wavelengths, allowing for the distinguishing between the contributions of the two semiconductive components. Experimental results showed that the decoration of WO3 nanoplates by Cu2O nanoparticles led to an improvement in photocatalytic performance, regardless of used LED (Light-Emitting Diode) wavelength, even at low concentrations. By using scavengers selectively blocking reactive species involved in the discoloration reaction, we determined that the Cu2O/WO3 nanocomposite exhibited the characteristics of direct Z-scheme-type photocatalyst.

scholarly journals Nano-MnO2 Decoration of TiO2 Microparticles to Promote Gaseous Ethanol Visible Photoremoval

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 686 ◽  
Author(s):  
Marta Stucchi ◽  
Daria Boffito ◽  
Eleonora Pargoletti ◽  
Giuseppina Cerrato ◽  
Claudia Bianchi ◽  
...  
Keyword(s):  
Visible Light ◽  
High Performance ◽  
Noble Metals ◽  
Large Scale ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Light Emitting ◽  
Physico Chemical ◽  
Visible Light Active ◽  
Activity Screening

TiO2-based photocatalysis under visible light is an attractive way to abate air pollutants. Moreover, developing photocatalytic materials on a large-scale requires safe and low-cost precursors. Both high-performance TiO2 nanopowders and visible-light active noble metals do not match these requirements. Here, we report the design of novel Mn-decorated micrometric TiO2 particles. Pigmentary TiO2 replaced unsafe nano-TiO2 and firmly supported MnOx particles. Mn replaced noble metals such as Au or Ag, opening the way for the development of lower cost catalysts. Varying Mn loading or pH during the impregnation affected the final activity, thus giving important information to optimize the synthesis. Photocatalytic activity screening occurred on the gas-phase degradation of ethanol as a reference molecule, both under ultraviolet (UV) (6 h) and Light Emitting Diode (LED) (24 h) irradiation. Mn-doped TiO2 reached a maximum ethanol degradation of 35% under visible light after 24 h for the sample containing 20% of Mn. Also, we found that an acidic pH increased both ethanol degradation and mineralization to CO2, while an alkaline pH drastically slowed down the reaction. A strict correlation between photocatalytic results and physico-chemical characterizations of the synthesized powders were drawn.

scholarly journals In vitro rapid inactivation of SARS-CoV-2 by visible light photocatalysis using boron-doped bismuth oxybromide

2021 ◽  
Author(s):  
Li Ling ◽  
Tea Carletti ◽  
Zihang Cheng ◽  
Ruixuan Wang ◽  
Yanxiao Ren ◽  
...  
Keyword(s):  
Visible Light ◽  
Culture Media ◽  
Light Emitting Diode ◽  
Emerging Pathogens ◽  
Light Emitting ◽  
Healthy Environment ◽  
Boron Doped ◽  
Visible Light Active ◽  
Led Irradiation

AbstractInactivation of SARS-CoV-2 in wastewater and on surfaces is critical to prevent the fecal-oral and fomite transmission, respectively. We hypothesized that visible light active photocatalysts could dramatically enhance the rate or extent of virus inactivation and enable the use of visible light rather than shorter wavelength ultraviolet light. A novel visible light active photocatalyst, boron-doped bismuth oxybromide (B-BiOBr), was synthesized and tested for its SARS-CoV-2 inactivation towards Vero E6 cell lines in dark and under irradiation at 426 nm by a light emitting diode (LED) in water. SARS-CoV-2 inactivation in the presence of B-BiOBr (0.8 g/L) under LED irradiation reached 5.32-log in 5 min, which was 400 to 10,000 times higher than those achieved with conventional photocatalysts of tungsten or titanium oxide nanomaterials, respectively. Even without LED irradiation, B-BiOBr inactivated 3.32-log of SARS-CoV-2 in the dark due to the ability of bismuth ions interfering with the SARS-CoV-2 helicase function. LED irradiation at 426 nm alone, without the photocatalyst, contributed to 10% of the observed inactivation and was attributed to production of reactive oxygen species due to blue-light photoexcitation of molecules in the culture media, which opens further modes of action to engineer disinfection strategies. The visible light active B-BiOBr photocatalyst, with its rapid SARS-CoV-2 inactivation in the presence and absence of light, holds tremendous opportunities to build a healthy environment by preventing the fecal-oral and fomite transmission of emerging pathogens.

Broadband near-infrared BaMSi3O9:Cr3+ (M = Zr, Sn, Hf) phosphors for light-emitting diode applications

2021 ◽  
Author(s):  
Yan Zhang ◽  
Yanjie Liang ◽  
Shihai Miao ◽  
Dongxun Chen ◽  
Shao Yan ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Near Infrared ◽  
Light Emitting Diode ◽  
Solid State Reaction Method ◽  
Luminescence Properties ◽  
Light Emitting ◽  
Reaction Method ◽  
Simple Solid State Reaction

A series of Cr3+-doped BaMSi3O9 (M = Zr, Sn, Hf) near-infrared emitting phosphors with tunable luminescence properties have been successfully synthesized by using a simple solid-state reaction method. The developed...

The Intellectual Lighting And Data Transmission System based On RGBW Light Emitting Diodes

2021 ◽  
pp. 63-68
Author(s):  
Daniil S. Shiryaev ◽  
Olga A. Kozyreva ◽  
Ivan S. Polukhin ◽  
Sergey A. Shcheglov ◽  
Svetlana A. Degtiareva ◽  
...  
Keyword(s):  
Visible Light ◽  
Data Transmission ◽  
Light Transmission ◽  
Transmission Rate ◽  
Light Emitting Diode ◽  
Spectral Characteristics ◽  
System Component ◽  
Transmission Channel ◽  
Error Vector Magnitude ◽  
Light Emitting

The system of intellectual lighting data transmission via visible light is developed and manufactured. Spectral characteristics of a downlink which uses the red crystal of a RGBW light emitting diode for data transfer were studied. The DALI protocol-based radiation chromaticity control system which allows us to set different lighting scenarios with constant data transmission rate was developed. The radiation chromaticity range covers almost the entire colour gamut in the colour space. The system of high-frequency matching of system component impedances was developed and frequency characteristics of the suggested scheme were studied for development of the system. Optimal parameters of the signal for visual light communication such as carrier frequency, modulation type and band were determined. Observation of the constellation diagram which represents different values of the complex amplitude of the keyed signal in the form of a complex number on a quadrature plane (cosine and sine components of the carrying signal) and of fixation of the amplitude of the error vector magnitude (EVM) was selected as a method of study of the transmission channel quality. The value of EVM in the visible light transmission channel was significantly lower for signals with amplitude modulation than for phase-manipulated signals. When implementing different lighting change scenarios, radiation of other crystals of the light emitting diode crystals not used for transmission did not lead to increase of EVM by more than one percent.

Quantum dots in photocatalytic applications: efficiently enhancing visible light photocatalytic activity by integrating CdO quantum dots as sensitizers

2017 ◽  
Vol 19 (36) ◽  
pp. 24915-24927 ◽  
Author(s):  
A. H. Reshak
Keyword(s):  
Quantum Dots ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Band Gap ◽  
Visible Light Irradiation ◽  
Photocatalytic Performance ◽  
Optical Band Gap ◽  
Visible Light Active ◽  
Photocatalytic Applications ◽  
Visible Light Photocatalytic

The amalgamation of a wide optical band gap photocatalyst with visible-light-active CdO quantum dots (QDs) as sensitizers is one of the most efficient ways to improve photocatalytic performance under visible light irradiation.

Sign in / Sign up

Export Citation Format

Share Document