UV Light Activated Multi-Cycle Photoelectric Properties of TiO2 and CdS/TiO 2 Films in Formaldehyde

2021 ◽  
Vol 21 (11) ◽  
pp. 5642-5647
Author(s):  
Zhijun Zou ◽  
Zhongli Qu ◽  
Longtao Tang ◽  
Yang Qiu ◽  
Gaohua Liao ◽  
...  
Keyword(s):  
Bias Voltage ◽  
Cycle Time ◽  
Screen Printing ◽  
Uv Light ◽  
Photogenerated Electron ◽  
The Other ◽  
Electron Hole ◽  
Silar Method ◽  
Cycle Number ◽  
Photoelectric Properties

In this work, UV light activated multi-cycle photoelectric properties of TiO2 and CdS/TiO2 films in formaldehyde were researched. TiO2 film was prepared by screen printing, CdS/TiO2 compounded film was synthesized by SILAR method. XRD and FE-SEM was used to characterize the TiO2 and CdS/TiO2 samples. Multi-cycle photoelectric properties of TiO2 and CdS/TiO2 with uv light on and off were evaluated by testing the photocurrent. On one hand, under the same bias voltage, CdS/TiO 2showed a higher photocurrent than that by TiO2. The reason for this result should be ascribed to the compounded structure in CdS/TiO2, with which the separation and transfer of photogenerated electron-hole pairs could be improved. On the other hand, with the testing cycle number increased, the photocurrent amplitudes of TiO2 and CdS/TiO2 increased. These results suggested that the time to reach a stable photocurrent value for TiO2 and CdS/TiO2 is much longer than one cycle time (300 S). To illustrate the increased photocurrent amplitude value cycle by cycle, the photocurrent of CdS/TiO2 to a much longer time (more than 4000 seconds) was also tested. To explain these results, corresponding possible illustrations were presented.

UV Light Driven Photoelectric Properties of ZnO Film to Humidity

2020 ◽  
Vol 20 (12) ◽  
pp. 7516-7521
Author(s):  
Zhijun Zou ◽  
Tan Tan ◽  
Gaohua Liao ◽  
Chang Li ◽  
Xiaoxiang Sun ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Bias Voltage ◽  
Screen Printing ◽  
Photoelectric Property ◽  
Uv Light ◽  
The Other ◽  
Time Dependent ◽  
Zno Film ◽  
Photoelectric Properties ◽  
Other Hand

UV light driven photoelectric properties of ZnO film to humidity were researched. ZnO film was prepared through the method of screen printing sustained on Al2O3 substrate. ZnO was characterized by XRD, FE-SEM and EDX. The time-dependent UV light driven photoelectric properties of ZnO were investigated by exposing it to different bias voltages and different relative humidity (20% RH, 40% RH, 60% RH and 80% RH). On one hand, the photoelectric properties of ZnO increased with the augmenting of bias voltage, which shows that a higher bias causes more separation of carriers. On the other hand, the photocurrent decreased with the increase in relative humidity, which shows that bigger humidity results in smaller photoelectric property. To discuss these results, corresponding possible illustrations for the photoelectric properties under different conditions were proposed.

scholarly journals A Review on Metal Ions Modified TiO2 for Photocatalytic Degradation of Organic Pollutants

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1039
Author(s):  
Dafu Jiang ◽  
Tunmise Ayode Otitoju ◽  
Yuanyuan Ouyang ◽  
Noor Fazliani Shoparwe ◽  
Song Wang ◽  
...  
Keyword(s):  
Metal Ions ◽  
Active Sites ◽  
Crystal Surface ◽  
Uv Light ◽  
Photogenerated Electron ◽  
Tio2 Photocatalyst ◽  
Electron Hole ◽  
Visible Light Range ◽  
Low Toxicity ◽  
High Chemical Stability

TiO2 is a semiconductor material with high chemical stability and low toxicity. It is widely used in the fields of catalysis, sensing, hydrogen production, optics and optoelectronics. However, TiO2 photocatalyst is sensitive to ultraviolet (UV) light; this is why its photocatalytic activity and quantum efficiency are reduced. To enhance the photocatalytic efficiency in the visible light range as well as to increase the number of the active sites on the crystal surface or inhibit the recombination rate of photogenerated electron–hole pairs electrons, various metal ions were used to modify TiO2. This review paper comprehensively summarizes the latest progress on the modification of TiO2 photocatalyst by a variety of metal ions. Lastly, the future prospects of the modification of TiO2 as a photocatalyst are proposed.

scholarly journals Photocatalytic Adsorption Synergistic Degradation of Tetracycline by Z-scheme Bi2WO6/ZIF-8

2021 ◽  
Author(s):  
Xiaojun Dai ◽  
sheng feng ◽  
Wei Wu ◽  
Yun Zhou ◽  
Zhiwei Ye ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Uv Light ◽  
Photogenerated Electron ◽  
Utilization Efficiency ◽  
Electron Hole ◽  
Effects Of Ph ◽  
Growth Method ◽  
Synergistic Degradation ◽  
First Time

Abstract In this paper, in order to improved the photocatalytic activity of Bi2WO6, Bi2WO6 and ZIF-8 were successfully combined by in-situ growth method for the first time. The addition of ZIF-8 effectively inhibited the recombination of photogenerated electron hole pairs and further improved the electron utilization efficiency, and superoxide anion was introduced to greatly improve the photocatalytic activity. The performance of Bi2WO6/ZIF-8 in the photodegradation of tetracycline (TC) was studied under different conditions of proportions of ZIF-8, dosage of catalyst and concentration of TC. The results indicated that B/Z/5/1 (10mg) had the best photocatalytic activity, and 97.8% of TC (20mg/L) could be degraded in 80 minutes under UV light, the rate constant (k) for TC degradation was almost 3 times that of Bi2WO6. The effects of pH, HA and inorganic anions on the degradation of TC were studied in simulated real water. Further, B/Z/5/1 could be reutilized up to five cycles without reduction of efficiency and catalysis performance. Therefore, Bi2WO6/ZIF-8 heterojunction composite material can be utilized as an efficient photocatalyst for remediation of environmental pollution.

The Tradition of Religious Books (Kitabs) Printing: Case Study of the Production and Reproduction of Religious Books (Kitabs) in Cianjur and Sukabumi, West Java, Indonesia

2020 ◽  
Vol 17 (2) ◽  
pp. 291-320
Author(s):  
Asep Saefullah
Keyword(s):  
Data Collection ◽  
Screen Printing ◽  
The Other ◽  
West Java ◽  
Simple Method ◽  
Original Essays ◽  
Printed Books ◽  
Religious Books ◽  
Living Tradition

Tulisan ini membahas fenomena penyebaran kitab-kitab cetak keaga­maan di Jawa Barat, khususnya di Sukabumi dan Cianjur. Jenis kitab ini biasanya menggunakan tulisan Arab dengan bahasa Sunda dan menggu­nakan aksara Pegon. Kitab-kitab cetak dari jenis-jenis itu diproduksi dan direproduksi, dan masih digunakan sampai hari ini. Oleh karena itu, fenomena ini dapat disebut sebagai “living tradition”. Pengumpulan data dilakukan dengan melacak dan merekam kitab-kitab yang diproduksi (disalin atau dikarang) dan direproduksi (dicetak atau digandakan) dengan metode seder­hana, yakni fotocopi dan pencetakan tradisional seperti stensil, sablon, dan "cetak toko". Tulisan ini bertujuan untuk memetakan dan merevisi kategorisasi kitab-kitab tersebut dari kajian terdahulu berdasarkan jenis karya, seperti karangan asli, tuqilan, terjemahan, syarḥ (penjelasan), khulasah (ringkasan) yang lain, dan juga berdasarkan bahasa dan aksara yang digunakan. Selain itu, tulisan ini juga mengamati lembaga-lembaga atau individu-individu yang masih mereproduksi buku-buku (kitab-kitab) keagamaan sederhana seperti perusahaan percetakan atau pesantren yang menerbitkan kitab-kitab tersebut. Pada akhir artikel ini, ada beberapa saran dalam upaya untuk melestarikan kitab-kitab cetak dan karya-karya tersebut.Kata kunci: kitab, jenis karya, pencetakan tradisional, Sunda, Pegon, Jawa Barat This paper discusses the phenomenon of the spreading of religious printed books (kitabs) in West Java, especially in Sukabumi and Cianjur, which are characterized by the use of Arabic writing in Sundanese (or known as Pegon script). The printed books (Kitabs) of those types are produced and reproduced, and are still used to this day. Therefore, this phenomenon can be called as a “living tradition”. Data collection was conducted by tracing and recording religious books (kitabs) that are pro-duced (rewritten or compossed) and reproduced (printed or duplicated) with a simple method, known as photocopying and traditional printing such as stencils, screen printing, and “shop printing”. This paper aims to map and revise the categorization of these Kitabs from previous studies based on the types of works including original essays, tuqilan (quotations), translation, sharh (explanation), khulaṣah (summary), or the other, and also based on the language and the script used. In addition, this paper also observes the institutions or individuals that are still reproducing these printed religious books such as the printing company or pesantren that publish such kitabs. At the end of this article, there are some suggestions in attempts to preserve those printed kitabs and the works.Keywords: Kitabs, type of work, traditional printing, Sunda, Pegon, West Java

scholarly journals Construction of Ag3PO4/SnO2 Heterojunction on Carbon Cloth with Enhanced Visible Light Photocatalytic Degradation

2020 ◽  
Vol 10 (9) ◽  
pp. 3238
Author(s):  
Min Liu ◽  
Guangxin Wang ◽  
Panpan Xu ◽  
Yanfeng Zhu ◽  
Wuhui Li
Keyword(s):  
Visible Light ◽  
Photocatalytic Performance ◽  
Separation Efficiency ◽  
Photogenerated Electron ◽  
Carbon Cloth ◽  
Electron Hole ◽  
Step Process ◽  
Photogenerated Electrons ◽  
Rapid Transfer ◽  
Visible Light Photocatalytic

In this study, the Ag3PO4/SnO2 heterojunction on carbon cloth (Ag3PO4/SnO2/CC) was successfully fabricated via a facile two-step process. The results showed that the Ag3PO4/SnO2/CC heterojunction exhibited a remarkable photocatalytic performance for the degradation of Rhodamine B (RhB) and methylene blue (MB), under visible light irradiation. The calculated k values for the degradation of RhB and MB over Ag3PO4/SnO2/CC are 0.04716 min−1 and 0.04916 min−1, which are higher than those calculated for the reactions over Ag3PO4/SnO2, Ag3PO4/CC and SnO2/CC, respectively. The enhanced photocatalytic activity could mainly be attributed to the improved separation efficiency of photogenerated electron-hole pairs, after the formation of the Ag3PO4/SnO2/CC heterojunction. Moreover, carbon cloth with a large specific surface area and excellent conductivity was used as the substrate, which helped to increase the contact area of dye solution with photocatalysts and the rapid transfer of photogenerated electrons. Notably, when compared with the powder catalyst, the catalysts supported on carbon cloth are easier to quickly recycle from the pollutant solution, thereby reducing the probability of recontamination.

UV Irradiation of Shell Eggs: Effect on Populations of Aerobes, Molds, and Inoculated Salmonella typhimurium

1997 ◽  
Vol 60 (6) ◽  
pp. 639-643 ◽  
Author(s):  
FUENG-LIN KUO ◽  
JOHN B. CAREY ◽  
STEVEN C. RICKE
Keyword(s):  
Salmonella Typhimurium ◽  
Uv Radiation ◽  
Uv Light ◽  
The Other ◽  
Uv Exposure ◽  
Microbial Populations ◽  
Aerobic Bacteria ◽  
Fluorescent Light ◽  
Uv Treatment ◽  
Shell Eggs

The effects were investigated of 254-nm UV radiation on populations of Salmonella typhimurium, aerobes, and molds on the shells of eggs. In the first experiment, the CFU of attached S. typhimurium cells on unwashed clean shell eggs were determined after 0, 1, 3, 5, and 7 min of UV treatment (620 μW/cm2) on both ends of the egg. All UV treatments significantly reduced S. typhimurium CFU (P < .01). UVtreatment (620 μW/cm2) in 1-min alternating light and dark cycles for 5 min (three light and two dark) was compared to 0, 3, and 5 min of UV treatment. No significant differences in microbial populations were observed among light and dark cycles and the other UV treatments. In a subsequent experiment, the same UV treatments were utilized to evaluate photoreactivation. After UV exposure, eggs were exposed to 1 h of fluorescent light or I h of darkness or cultured immediately. S. typhimurium CFU were significantly (P < .01) reduced by the UV treatments. However, no significant differences between microbial populations exposed to UV treatment and UV radiation plus photoreactivation were detected. For studies of aerobic bacteria and molds, different UV treatment times (0, 15, and 30 min) at the intensity of 620 μW/cm2 and different intensities (620, 1350, and 1720 μW/cm2) for 15 min were evaluated. Mold CFU per egg were either 0 or 1 for all UV treatments and a 99% reduction of CFU of aerobic bacteria per egg were observed for all UV treatments. It appears from these studies that UV light can significantly reduce populations of S. typhimurium, aerobes, and molds on shell eggs.

scholarly journals Preparation and Photocatalytic Performance for Degradation of Rhodamine B of AgPt/Bi4Ti3O12 Composites

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2206
Author(s):  
Gaoqian Yuan ◽  
Gen Zhang ◽  
Kezhuo Li ◽  
Faliang Li ◽  
Yunbo Cao ◽  
...  
Keyword(s):  
Visible Light ◽  
Noble Metal ◽  
Rhodamine B ◽  
Photocatalytic Performance ◽  
Bimetallic Nanoparticles ◽  
Resonance Effect ◽  
Visible Region ◽  
Photogenerated Electron ◽  
Pt Nanoparticles ◽  
Electron Hole

Loading a noble metal on Bi4Ti3O12 could enable the formation of the Schottky barrier at the interface between the former and the latter, which causes electrons to be trapped and inhibits the recombination of photoelectrons and photoholes. In this paper, AgPt/Bi4Ti3O12 composite photocatalysts were prepared using the photoreduction method, and the effects of the type and content of noble metal on the photocatalytic performance of the catalysts were investigated. The photocatalytic degradation of rhodamine B (RhB) showed that the loading of AgPt bimetallic nanoparticles significantly improved the catalytic performance of Bi4Ti3O12. When 0.10 wt% noble metal was loaded, the degradation rate for RhB of Ag0.7Pt0.3/Bi4Ti3O12 was 0.027 min−1, which was respectively about 2, 1.7 and 3.7 times as that of Ag/Bi4Ti3O12, Pt/Bi3Ti4O12 and Bi4Ti3O12. The reasons may be attributed as follows: (i) the utilization of visible light was enhanced due to the surface plasmon resonance effect of Ag and Pt in the visible region; (ii) Ag nanoparticles mainly acted as electron acceptors to restrain the recombination of photogenerated electron-hole pairs under visible light irradiation; and (iii) Pt nanoparticles acted as electron cocatalysts to further suppress the recombination of photogenerated electron-hole pairs. The photocatalytic performance of Ag0.7Pt0.3/Bi4Ti3O12 was superior to that of Ag/Bi4Ti3O12 and Pt/Bi3Ti4O12 owing to the synergistic effect between Ag and Pt nanoparticles.

scholarly journals Tunable electronic and optical properties of a BAs/As heterostructure by vertical strain and external electric field

RSC Advances ◽  
2021 ◽  
Vol 11 (35) ◽  
pp. 21824-21831
Author(s):  
X. Q. Deng ◽  
R. Q. Sheng ◽  
Q. Jing
Keyword(s):  
Optical Properties ◽  
Electric Field ◽  
External Electric Field ◽  
Photogenerated Electron ◽  
Electron Hole ◽  
Electronic And Optical Properties ◽  
Vertical Strain

The CBM (VBM) of the heterostructure is mainly contributed by the BAs (arsenene), which will favor the separation of photogenerated electron–hole pairs.

One-Step Hydrothermal Synthesis of Bi2S3-TiO2-RGO Composites with Enhanced Visible Light Photocatalytic Activities

NANO ◽  
2018 ◽  
Vol 13 (05) ◽  
pp. 1850051 ◽  
Author(s):  
Yanan Li ◽  
Zhongmin Liu ◽  
Yaru Li ◽  
Yongchuan Wu ◽  
Jitao Chen ◽  
...  
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Photogenerated Electron ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Photocatalytic Ability ◽  
Transmission Electron ◽  
Light Region ◽  
Infrared Spectrometer ◽  
One Step

The Bi2S3-TiO2-RGO composites were synthesized by a facile one-step hydrothermal method and applied for the photocatalytic degradation of Rhodamine B (Rh B) under the visible light. The Bi2S3-TiO2-RGO composites were characterized by transmission electron microscopy, X-ray diffraction, Raman and Fourier transform infrared spectrometer. The results indicated that the Bi2S3-TiO2-RGO composites were successfully prepared, and Ti-O-C and S-C bonds were existing among Bi2S3, TiO2 as well as RGO. Furthermore, the photocatalytic ability of Bi2S3-TiO2-RGO composites was excellent under visible light due to its responding to the whole visible light region, low recombination rate of photogenerated electron–hole pairs and relatively negative conduction band. Rh B photocatalytic degradation rate was 99.5% after 50[Formula: see text]min and still could reach 98.4% after five cycles. Finally, a formation mechanism as well as a photocatalytic mechanism of Bi2S3-TiO2-RGO composites were proposed based on the experimental results.

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