Enhancing the Photocatalytic Activity of SnO2-TiO2 and ZnO-TiO2 Tandem Structures Toward Indoor Air Decontamination

Film Density ◽

Doctor Blade ◽

Constant Rate ◽

Tandem Structure

ZnO-TiO2 and SnO2-TiO2 tandem structures were developed using the doctor blade technique. It was found that by employing organic hydrophilic and hydrophobic as additives into the precursor it is possible to tailor the film density and morphology with direct consequences on the photocatalytic activity of the tandem structures. The highest photocatalytic efficiency corresponds to ZnO-TiO2 and can reach 74.04% photocatalytic efficiency toward acetaldehyde when a hydrophilic additive is used and 70.93% when a hydrophobic additive is employed. The snO2-TiO2 tandem structure presents lower photocatalytic properties (61.35 % when the hydrophilic additive is used) with a constant rate reaction of 0.07771 min−1.

β-FeSe nanorods composited g-C 3 N 4 with enhanced photocatalytic efficiency

Royal Society Open Science ◽

10.1098/rsos.181886 ◽

2019 ◽

Vol 6 (3) ◽

pp. 181886 ◽

Cited By ~ 2

Author(s):

Shijie Shen ◽

Wenwu Zhong ◽

Zongpeng Wang ◽

Zhiping Lin ◽

Shangshen Feng

Keyword(s):

Organic Matter ◽

Photocatalytic Activity ◽

Electrochemical Impedance ◽

Chemical State ◽

Co Catalyst ◽

Photogenerated Electrons ◽

Structure Morphology

A series of β-FeSe nanorods composited g-C 3 N 4 were prepared. The structure, morphology, chemical state, photocatalytic activity, electrochemical impedance and photoluminescence of β-FeSe/g-C 3 N 4 composites were well characterized. It is found that the decolourization rate of 3 wt% β-FeSe/g-C 3 N 4 composites reaches 4.4 times than that of g-C 3 N 4 . The improved photocatalytic properties could be ascribed to the reduced recombination of photogenerated electrons and holes, which is derived from the excellent ability of β-FeSe to capture and transfer electrons. This work provides an alternative co-catalyst for decolourizing organic matter.

Tandem Structures Semiconductors Based on TiO2_SnO2 and ZnO_SnO2 for Photocatalytic Organic Pollutant Removal

Nanomaterials ◽

10.3390/nano11010200 ◽

2021 ◽

Vol 11 (1) ◽

pp. 200

Author(s):

Alexandru Enesca ◽

Luminita Isac

Keyword(s):

Photocatalytic Activity ◽

Uv Radiation ◽

Organic Pollutant ◽

Pollutant Removal ◽

Mass Ratio ◽

Experimental Conditions ◽

Kinetic Evaluation ◽

Tandem Structure ◽

Main Component

The photocatalyst materials correlation with the radiation scenario and pollutant molecules can have a significant influence on the overall photocatalytic efficiency. This work aims to outline the significance of optimizing the components mass ratio into a tandem structure in order to increase the photocatalytic activity toward pollutant removal. ZnO_SnO2 and TiO2_SnO2 tandem structures were obtained by the doctor blade technique using different mass ratios between the components. The samples contain metal oxides with crystalline structures and the morphology is influenced by the main component. The photocatalytic activity was tested using three radiation scenarios (UV, UV-Vis, and Vis) and two pollutant molecules (tartrazine and acetamiprid). The results indicate that the photocatalytic activity of the tandem structures is influenced by the radiation wavelength and pollutant molecule. The TiO2_SnO2 exhibit 90% photocatalytic efficiency under UV radiation in the presence of tartrazine, while ZnO_SnO2 exhibit 73% photocatalytic efficiency in the same experimental conditions. The kinetic evaluation indicate that ZnO_SnO2 (2:1) have a higher reaction rate comparing with TiO2_SnO2 (1:2) under UV radiation in the presence of acetamiprid.

Photocatalytic Activity of Cu2S/WO3 and Cu2S/SnO2 Heterostructures for Indoor Air Treatment

Materials ◽

10.3390/ma14133656 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3656

Author(s):

Alexandru Enesca ◽

Luminita Isac

Keyword(s):

Photocatalytic Activity ◽

Indoor Air ◽

Building Materials ◽

Removal Rate ◽

International Agency ◽

Carcinogenic Potential ◽

Constant Rate ◽

Carcinogenic Effects ◽

Oxide Substrate ◽

Oxidative Processes

Volatile organic compounds (VOCs) are commonly found in indoor spaces (e.g., homes or offices) and are often related to various illnesses, some of them with carcinogenic potential. The origins of VOC release in the indoor environment are in office products, building materials, electronics, cleaning products, furniture, and maintenance products. VOC removal can be done based on two types of technologies: adsorption in specific materials and decomposition via oxidative processes. The present article reports the development and photocatalytic activity of two heterostructures (Cu2S/WO3 and Cu2S/SnO2) used for indoor air decontamination. The acetaldehyde removal rate is discussed in correlation with the S-scheme mechanisms established between the heterostructure components but also comparatively with the bare catalysts’ activity. Acetaldehyde was considered as a VOC reference because it was found by the International Agency for Research on Cancer to be one of the most frequent air toxins with potential carcinogenic effects. The samples contained monoclinic WO3, tetragonal SnO2, and orthorhombic Cu2S crystalline structures. The Cu2S crystallite size in the heterostructure varied from 75.9 to 82.4 Å, depending on the metal oxide substrate. The highest photocatalytic efficiency (75.7%) corresponded to Cu2S/SnO2, with a constant rate of 0.106 s−1 (which was three times faster than WO3 or SnO2 and seven and a half times faster than Cu2S).

Photocatalytic activity of Pr-modified TiO2 for the degradation of bisphenol A

SN Applied Sciences ◽

10.1007/s42452-021-04284-2 ◽

2021 ◽

Vol 3 (2) ◽

Author(s):

Denise S. Cordeiro ◽

Fernando L. Cassio ◽

Larissa Ciccotti ◽

Thiago L. R. Hewer ◽

Paola Corio ◽

...

Keyword(s):

Photocatalytic Activity ◽

Bisphenol A ◽

Pore Diameter ◽

Sol Gel ◽

Bandgap Energy ◽

Average Pore ◽

X Ray ◽

Vis Spectroscopy ◽

Adsorption Desorption

AbstractPraseodymium doped TiO2 nanoparticles were successfully prepared by the sol–gel method and characterized by X-ray powder diffraction, N2 adsorption–desorption isotherm, and UV–vis spectroscopy. The effects of the dopant on the crystallite size, specific surface area, average pore diameter, pore volume, and bandgap energy were investigated. The photocatalytic activity of the catalysts was evaluated by bisphenol A degradation and mineralization, which is a representative endocrine disruptor. Furthermore, under visible light irradiation the Pr-modified TiO2 photocatalysts exhibited higher photocatalytic efficiency than unmodified TiO2. When praseodymium was loaded (1.0–5.0%) onto the surface of TiO2, the rates of degradation and mineralization were increased 3–5 times.

Cuprous Oxide Films Deposition by Mid-Frequency Magnetron Sputtering and Their Photocatalytic Activity under Visible Light

NANO ◽

10.1142/s1793292021501290 ◽

2021 ◽

Author(s):

Z. X. Mu ◽

H. Li ◽

X. N. Deng

Keyword(s):

Photocatalytic Activity ◽

Magnetron Sputtering ◽

Visible Light ◽

Cuprous Oxide ◽

Deposition Time ◽

Visible Region ◽

Mixed Phase ◽

Oxygen Flow ◽

Photocatalytic Films

Cuprous oxide (Cu2O) has attracted much attention as a photocatalytic material. In this paper, the mid-frequency reactive magnetron sputtering method was used to prepare Cu2O films on glass slides, and the effects of oxygen flow and deposition time on the structures, morphologies and photocatalytic properties of the films were studied. The results show that the films prepared by this method have smooth surfaces and good absorptivity in the visible region. As the oxygen flow increases, the films transit from the mixed-phase of Cu and Cu2O to the single-phase of Cu2O. When the oxygen flow continues to increase, the films change to a mixed-phase of Cu4O3 and Cu2O. The photocatalytic decolorization of methyl orange under visible light irradiation conditions was used to assess the photocatalytic properties of the prepared films. When the oxygen flow is 6[Formula: see text]sccm and the deposition time is 15[Formula: see text]min, the film exhibits the best photocatalytic activity. Finally, the Mulliken electronegativity theory was used to explain the photocatalytic mechanism of Cu2O. This study confirmed the feasibility of preparing Cu2O photocatalytic films by magnetron sputtering, and provided the experimental basis for the subsequent study of Cu2O photocatalytic films.

Structure, morphology features and photocatalytic properties of α-Ag2WO4 nanocrystals-modified Palygorskite clay

Journal of Photocatalysis ◽

10.2174/2665976x02666210210163001 ◽

2021 ◽

Vol 02 ◽

Author(s):

Amanda Carolina Soares Jucá ◽

Francisco Henrique Pereira Lopes ◽

Herbert Vieira Silva-Júnior ◽

Lara Kelly Ribeiro Silva ◽

Elson Longo ◽

...

Keyword(s):

Photocatalytic Activity ◽

Rhodamine B ◽

Dye Degradation ◽

Degradation Kinetics ◽

Low Cost ◽

Catalytic Efficiency ◽

Impregnation Method ◽

Heat Treated ◽

Modified Palygorskite

Aims: In the present study, we investigate the photocatalytic properties of α-Ag2WO4 nanocrystals-modified Palygorskite (PAL) clay synthesized by the impregnation method. The PAL clay was chemically purified and heat-treated (500 ºC for 2 h), which served as an excellent supporting matrix for loading α-Ag2WO4(α-AWO) nanocrystals. Background: Water contamination is one of the most serious problems affecting human health, ecosystem survival, and the economic growth of societies. Industrial effluents, such as textile dyes, when not treated and improperly discharged into water resources are considered the main cause of water pollution. Thus the scientific community has been developing effective remediation technologies based on advanced oxidative processes to reduce the harmful effects of these organic pollutants. Objective: Improve the photocatalytic activity of PAL clay with α-AWO nanocrystals to degradation of Rhodamine B (RhB) dye. Methods: We purify and heat-treated the PAL clay, synthesize nanocrystals ofα-AWO nanocrystals and modify PAL clay with 30% α-AWO nanocrystals by the impregnation method. The modified PAL clay was able to improve RhB dye degradation. The materials were characterized by XRD, RAMAN,FE-SEM, FT-IR, XRF, etc. The samples were used as photocatalysts under UV-C lamps for the degradation of RhB dye in order to analyze its catalytic performances. Results: ThePAL clay modified with 30% α-AWO nanocrystals showed a catalytic efficiency of 79%, and degradation kinetics about 16 times higher when compared to PAL-500 only purified and heat-treated at 500 ºC. In this way, this PAL-modified is an alternative as a low-cost photocatalyst for the degradation of RhB dye. Conclusion: Ultraviolet-Visiblespectra revealed that our materials have opticalband gap energies controlled by indirect and direct electronic transitions and suitable to be activated under ultraviolet illumination. The adequate amount (30 wt.%) of α-Ag2WO4 nanocrystals added to PAL brought significant improvement of photocatalytic activity for the degradation of rhodamine B. Finally, a photocatalytic mechanism was proposed in detail.

Controlling the morphology and composition of Ag/AgBr hybrid nanostructures and enhancing their visible light induced photocatalytic properties

RSC Advances ◽

10.1039/c6ra08682a ◽

2016 ◽

Vol 6 (60) ◽

pp. 54709-54717 ◽

Cited By ~ 13

Author(s):

Aasim Shahzad ◽

Taekyung Yu ◽

Woo-Sik Kim

Keyword(s):

Methylene Blue ◽

Photocatalytic Activity ◽

Visible Light ◽

Hybrid Nanostructures ◽

Photocatalytic Properties

Ag/AgBr hybrid nanostructures were prepared by reducing AgBr nanoparticles synthesized by reaction of Ag+ with Br−. The Ag/AgBr hybrid nanostructures exhibited enhanced photocatalytic activity and recyclability for decomposing methylene blue (MB).

Electrochemical Synthesis and Photocatalytic Activity of Differently Shaped CuOx Particles

Nano Hybrids and Composites ◽

10.4028/www.scientific.net/nhc.13.330 ◽

2017 ◽

Vol 13 ◽

pp. 330-333

Author(s):

Anna Ulyankina ◽

Igor Leontyev ◽

Nina Smirnova

Keyword(s):

Electron Microscopy ◽

Photocatalytic Activity ◽

Electrochemical Method ◽

Spherical Particles ◽

X Ray Diffraction ◽

X Ray ◽

Polyhedral Particles ◽

Copper Electrodes ◽

Scanning Electron

CuOx powders with diff erently shaped particles were firstly prepared via an electrochemical method by oxidation and dispersion of copper electrodes in an electrolyte solution under pulse alternating current (PAC). By means of X-ray diffraction (XRD) and scanning electron microscopy (SEM) the current density is found to have an influence on the morphology and composition of CuOx particles. Photocatalytic efficiency of CuOx towards methyl orange (MO) degradation under visible light was investigated. The prepared polyhedral particles show the best photocatalytic activity of 81 % towards MO comparing to octahedral and spherical particles with 70 and 61 %, respectively.

Synthesis, Structure, Optic and Photocatalytic Properties of Anatase/Brookite Nanocomposites

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.64.39 ◽

2020 ◽

Vol 64 ◽

pp. 39-48

Author(s):

Volodymyr Moklyak ◽

Volodymyr Chelyadyn ◽

Andrii Hrubiak ◽

Bogdan Ostafiychuk ◽

Volodymyr Kotsyubynsky ◽

...

Keyword(s):

Titanium Dioxide ◽

Photocatalytic Activity ◽

Hydrothermal Treatment ◽

Classical Method ◽

Hydrolysis Product ◽

Average Particle ◽

Oxide Material ◽

Buffer Solution ◽

Vis Spectroscopy

Anatase/brookite nanocomposites were fabricated by the classical method of hydrolysis, additionally using hydrothermal treatment of preformed titanium dioxide sol with tetrabutyl orthotitanate. The influence of hydrothermal processing the buffer solution of TiO2 synthesis on the average particle sizes, specific surface area, pore sizes distributions, optical and photocatalytic properties investigated by X-ray diffraction, low-temperature nitrogen adsorption and UV-Vis spectroscopy. It has been determined that the hydrothermal treatment of pre-prepared titania sol as hydrolysis product leads to rutile formation after annealing at 400°C. Respective model of forming anatase/brookite/rutile nanocomposites was proposed. The changes of bang gap energy of TiO2 were observed and explained by effect of change phase composition and particles size of nanocomposite particles. Methylene blue (MB) photo-oxidation reactions using titanium dioxide nanocomposite were analyzed. Maximal photocatalytic activity of MB oxidation was detected for material with the ratio of the titania phases (anatase : brookite : rutile – 2 : 2 : 1). Synergistic effect between crystallinity, phase ratio, morphology of oxide material, band gap and photocatalytic activity in the anatase/brookite nanocomposites was established.

The effect of Ag, Au, Pt, and Pd on the surface properties, photocatalytic activity and toxicity of multicomponent TiO2-based nanomaterials

Environmental Science Nano ◽

10.1039/d0en00580k ◽

2020 ◽

Vol 7 (11) ◽

pp. 3557-3574

Author(s):

Anna Malankowska ◽

Alicja Mikołajczyk ◽

Joanna Mędrzycka ◽

Izabela Wysocka ◽

Grzegorz Nowaczyk ◽

...

Keyword(s):

Photocatalytic Activity ◽

Surface Properties ◽

Rational Design ◽

Air Purification ◽

Component Concentration

A better understanding how to the component concentration, photocatalytic properties and toxicity of multicomponent TiO2-based nanomaterials (NMs) may lead to rational design of new and safe NMs with wide application in air purification.