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Synthesis and Characterization of Photocatalyst Nanocomposite for the Degradation of Organic Pollutants in Wastewater

Ratnawulan, Rahmadhani Detty, Fauzi Ahmad, Jonuarti Riri, Supian Faridah Lisa, Jhora Fadhila Ulfa

Journal of Ecological Engineering

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2023

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Vol. 24, nr 12

388--396

EN

Various efforts can be made to obtain clean water in the environment by utilizing semiconductor technology. This study aims to inform the synthesis and characterization of MnO2/CuO/Fe2O3 photocatalyst for crystal violet degradation in wastewater. Nanocomposite was synthesized through a sol-gel process with three semiconductor materials doped. X-ray diffraction (XRD) was employed to analyze the nanocomposite structure and determine crystal size. Fourier transform infrared (FTIR) was used to provide functional groups in the nanocomposite. A scanning electron microscope (SEM) can characterize surface morphology and particle size. The results of the SEM show that an increase in sintering temperature causes the smallest particle sizes to be 54.79 nm. The result of characterization using the ultraviolet-visible (Uv-Vis) spectrophotometry analysis the most effective band gap value in photocatalyst activity was 1.36 eV. The optimum percent of degradation MnO2/CuO/Fe2O3 catalyst was 50.40% for the sample at a temperature of 400 °C under irradiation with sunlight for six hours. Test results show that increased sintering temperature increased the photocatalytic activity.

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Pressure dependence of the band gap energy for dilute nitride and antimony GaNxSbyAs1−x−y

Zhao Chuan-Zhen, Ren He-Yu, Sun Xiao-Dong, Wang Sha-Sha, Lu Ke-Qing

Materials Science Poland

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2020

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Vol. 38, No. 2

248--252

EN

Dilute nitride and antimony GaNAsSb alloy can be considered as an alloy formed by adding N and Sb atoms into the host material GaAs. Under this condition, its band gap energy depending on pressure can be divided into two regions. In the low pressure range, the band gap energy is due to two factors. One is the coupling interaction between the N level and the Γ conduction band minimum (CBM) of GaAs. The other one is the coupling interaction between the Sb level and the Γ valence band maximum (VBM) of GaAs. In the high pressure range, the band gap energy depends also on two factors. One is the coupling interaction between the N level and the X CBM of GaAs. The other one is the coupling interaction between the Sb level and the Γ VBM of GaAs. In addition, it has been found that the energy difference between the Γ CBM and the X CBM in GaNAsSb is larger than that in GaAs. It is due to two factors. One is the coupling interaction between the N level and the Γ CBM of GaAs. The other is the coupling interaction between the N level and the X CBM of GaAs.

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Pressure dependence of the band gap energy for the dilute nitride GaNxAs1−x

Zhao C.-Z., Wei T., Sun X.-D., Wang S.-S., Lu K.-Q.

Materials Science Poland

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2016

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Vol. 34, No. 4

881--885

EN

A model is developed to describe the pressure dependence of the band gap energy for the dilute nitride GaNxAs1-x. It is found that the sublinear pressure dependence of E- is due to the coupling interaction between E+ and E-. We have also found that GaNxAs1-xneeds much larger pressure than GaAs to realize the transition from direct to indirect band gap. It is due to two factors. One is the coupling interaction between the E+ and E-. The other is that the energy difference between the X conduction band minimum (CBM) and the G CBM in GaNxAs1-x is larger than that in GaAs. In addition, we explain the phenomenon that the energy difference between the X CBM and the G CBM in GaNxAs1-xis larger than that in GaAs. It is due to the impurity-host interaction.

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Optical characterization of the CdZn(S1-x Sex )2 thin films deposited by spray pyrolysis method

Ilican S., Zor M., Caglar Y., Caglar M.

Optica Applicata

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2006

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Vol. 36, nr 1

29-37

EN

CdZn(S1-xSex )2 thin films have been deposited onto glass substrates by the spray pyrolysis method at a 275°C substrate temperature. The average optical transmittance of all the films was over 65% in the wavelength range 450-800 nm. The optical absorption studies reveal that the transition is direct with band gap energy values between 2.47-3.04 eV. The optical constants such as refractive index, extinction coefficient and dielectric constants have been calculated for these films. The dispersion parameters such as Eo (single-oscillator energy) and Ed (dispersive energy) have been discussed in terms of the Wemple-DiDomenico single-oscillator model. The values obtained by this method are suitable for many scientific studies and technological applications, such as gas sensors, heat mirrors, transparent electrodes, solar cells and piezoelectric devices.