scholarly journals Heterogeneous Photocatalysis

2021 ◽  
Vol 5 (2) ◽  
pp. 26
Author(s):  
Mario J. Muñoz-Batista ◽  
Rafael Luque
Keyword(s):  
Heterogeneous Photocatalysis ◽  
Chemical Processes

Heterogeneous photocatalysis is a subtype of catalysis that refers to chemical processes catalysed by a semiconductor solid under proper illumination conditions [...]

scholarly journals Performance Evaluation of the SrZrxSn1-xO3 Photocatalytic System for Remazol Yellow Dye Degradation Employing Box-Behnken Design

2021 ◽  
Vol 10 (2) ◽  
pp. e48610212328
Author(s):  
Yohanna Ribeiro Klafke ◽  
Mayara Macedo da Mata ◽  
Ieda Maria Garcia dos Satos ◽  
Mary Cristina Ferreira Alves ◽  
Simone da Silva Simoes
Keyword(s):  
Dye Degradation ◽  
Large Family ◽  
Heterogeneous Photocatalysis ◽  
Textile Dyes ◽  
Chemical Processes ◽  
Box Behnken Design ◽  
Structural Modifications ◽  
Photocatalytic System ◽  
Golden Yellow ◽  
By Products

Contamination of effluents often occurs due to improper disposal of textile dyes or their by-products. These can often be carcinogenic and/or mutagenic to the biome. Given the above, the need for effective methods for treating effluents is clear. This treatment occurs by biological, physical, and/or chemical processes. Regarding chemical processes, heterogeneous photocatalysis stands out, mainly because it guarantees an effective degradation of contaminants. In this sense, mixed metal oxides, act as photocatalysts and constitute structures capable of producing a large family of solids with physical properties suitable for the degradation of many pollutants. Modified ABO3 perovskites, as in the case of the SrZrxSn1-xO3 semiconductor system, are effective in the degradation of textile dyes in effluents. The present work aimed to use the Box-Behnken model to evaluate the performance of the oxides resulting from the structural modifications of the perovskite SrZrxSn1-xO3 system, concerning the discoloration of the golden yellow dye remazol. The synthesized oxides were characterized by instrumental techniques and a Box-Behnken 34 project was developed. From this, the influence of some factors such as structural modification, oxide mass, exposure time, and the number of UVC lamps was evaluated. The discoloration of the dye was monitored from the attenuation of the absorbance at the wavelength 411 nm. According to the results obtained, the highest percentage of discoloration was obtained using the modified oxide SrZr0,25Sn0,75O3 for an approximate time of 6 hours in contact with 1 UVC lamp.

Studies on degradation of glyphosate by several oxidative chemical processes: Ozonation, photolysis and heterogeneous photocatalysis

2009 ◽  
Vol 45 (1) ◽  
pp. 89-94 ◽  
Author(s):  
Marcia R. Assalin ◽  
Sandra G. De Moraes ◽  
Sonia C. N. Queiroz ◽  
Vera L. Ferracini ◽  
Nelson Duran
Keyword(s):  
Heterogeneous Photocatalysis ◽  
Chemical Processes

Polycaprolactone based membranes for the degradation of diclofenac present in water samples using ZnO nanoparticles as the active agent

MRS Advances ◽  
2020 ◽  
Vol 5 (61) ◽  
pp. 3153-3161
Author(s):  
Marco Antonio Juárez Sánchez ◽  
Miguel Ángel Meléndez Lira ◽  
Celestino Odín Rodríguez Nava
Keyword(s):  
Zno Nanoparticles ◽  
Wastewater Treatment Plants ◽  
Active Agent ◽  
Heterogeneous Photocatalysis ◽  
Nano Particles ◽  
Electrical Characteristics ◽  
Unit Operation ◽  
Fields Of Study ◽  
Drug Contamination ◽  
Positive Results

AbstractDrug contamination in water is one of the current fields of study. Since 1990, the presence of drugs in drinking water has been a concern to scientists and public. In Mexico, these organic compounds are not efficiently removed in wastewater treatment plants; therefore, alternative methodologies have been studied that allow these compounds to have a high percentage of degradation or be completely degraded. One example of these techniques is heterogeneous photocatalysis which has obtained positive results in the degradation of drugs using ZnO nanoparticles. These are commonly selected for their electrical characteristics, even though they disperse in water and an additional unit operation is required to separate them from the liquid medium. To eliminate drugs with nano particles in a single stage, polycaprolactone-based membranes with adhered ZnO nanoparticles, by means of electrospinning, were prepared to degrade drugs such as diclofenac. The technique used has shown to efficiently break down diclofenac in 4 hours according to the capillary electrophoresis readings.

Electrical Damage Due to Low Energy Plasma Processing of GaAs Structures

1991 ◽  
Vol 223 ◽  
Author(s):  
Hans P. Zappe ◽  
Gudrun Kaufel
Keyword(s):  
Chemical Processes ◽  
Low Energy ◽  
Electrical Behavior ◽  
Rapid Thermal Anneal ◽  
High Temperature Anneal ◽  
Significant Damage ◽  
Low Energies ◽  
Long Time ◽  
Physical Plasma

ABSTRACTThe effect of numerous plasma reative ion etch and physical milling processes on the electrical behavior of GaAs bulk substrates has been investigated by means of electric microwave absorption. It was seen that plasma treatments at quite low energies may significantly affect the electrical quality of the etched semiconductor. Predominantly physical plasma etchants (Ar) were seen to create significant damage at very low energies. Chemical processes (involving Cl or F), while somewhat less pernicious, also gave rise to electrical substrate damage, the effect greater for hydrogenic ambients. Whereas rapid thermal anneal treatments tend to worsen the electrical integrity, some substrates respond positively to long-time high temperature anneal steps.

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