Effect of the ratio ZnO: ZrO2 on the photocatalytic ability of phenol degradation in ZnO-ZrO2 nanocompsite materials

2021 ◽  
Vol 10 (3) ◽  
pp. xx-xx
Author(s):  
Thao Pham Thi Minh ◽  
Huong Do Thi ◽  
Hai Le Thi

The ZnO-ZrO2 nanocompsite materials in the molar ratio (1:0; 1:1; 1:2; 2:1; 3:4; 4:3; 0:1) were prepared by a two-stage precipitation method with ultrasonic vibrations. The obtained ZnO-ZrO2 materials were characterized by XRD, SEM, UV-vis. XRD data identified phase of the ZnO and phase of ZrO2 in all obtained samples. The average crystallite size of the samples was between 18 to 30 nm. As UV-Vis spectra, the band gap of ZnO-ZrO2 composite (ZZ34R) is 3,06eV. The photocatalytic reactions confirmed that the nanocomposite sample showed higher photocatalytic activity than the pure oxides samples for the degradation phenol under 100W incandescent lamp. Among the prepared samples, the best sample for photocatalytic degration of phenol is the ZZ34R which the molar ratio ZnO:ZrO2 = 3:4 with 23% remaining phenol content after 300 minutes. The photodegradation phenol of sample with ultrasonic vibrations is higher than the sample without ultrasonic vibrations. This indicates that the materials are capable of treating phenol in wastewater.

2014 ◽  
Vol 2 (46) ◽  
pp. 19589-19593 ◽  
Author(s):  
Yanna Guo ◽  
Hui Li ◽  
Jin Chen ◽  
Xuejing Wu ◽  
Lei Zhou

A totally novel, extremely easy, much greener and low-cost method has been developed to synthesize TiO2 mesocrystals. These materials are built of TiO2 nanocrystals with similar crystallographic orientation and largely exposed {001} facets. Their unique structure optimizes the relationship between specific surface area, crystallite size and active facets, and therefore leads to superior photocatalytic activity.


2020 ◽  
Vol 4 (1) ◽  
pp. 36
Author(s):  
Wahid Sidik Sarifuddin ◽  
Utari Utari ◽  
Budi Purnama

The crystalline structure and magnetic properties of Mn<sub>1-x</sub>Co<sub>x</sub>Fe<sub>2</sub>O<sub>4</sub> (x = 0 &amp; 0.25) was studied in this report. The ferrite materials were synthesized by the chemical co-precipitation method and calcinated at 1000<sup>o</sup>C for 5 hours. The obtained materials were characterized by FTIR, XRD and VSM, and for photocatalytic activity was measured by UV-Vis spectrometer. Vibration bands at tetrahedral and octahedral site were corresponded by <strong> </strong>= 581.56 cm<sup>-1</sup> and  = 465.83 cm<sup>-1</sup> and 474.51 cm<sup>-1</sup> . The obtained ferrite were confirmed by XRD as spinel structure and shown that the addition of number of Mn decreased crystallite size <em>(D)</em> and x-ray density (<em>ρ<sub>x</sub></em>), but lattice constants <em>(a)</em> increased. The crystallite size of samples with x = 0.50 was 34.85 nm, and x = 0.75 was 32.17 nm. The magnetic properties of nanoparticles shown that magnetization saturation <em>(</em><em>Ms)</em>from 42.05 emu/g to 54.16 emu/g increased with the addition of number of Mn. The coercive field (<em>H</em><sub>c</sub>)decreased from 408.27 Oe to 258.37 Oe. Photocatalytic activity was observed by UV-Vis spectrometer, where percentage of MB degradation <em>(E)</em> increase with the addition of number on Mn from 49.08% to 69.06%, either rate constant <em>(k<sub>app</sub>)</em> and half life time<em> (t<sub>1/2</sub>)</em>.  Furthermore, ferrite material base Mn-Co-ferrite has good characteristic to applied for photocatalyst.


Author(s):  
Mukholit, Heri Sutanto ◽  
Ngurah Ayu Ketut Umiati ◽  
Eko Hidayanto

Bi2O3 has successfully been synthesized using precipitation method with sintering temperature variations of 400oC, 450o C, 500o C, 550o C, and 600o C. Crystallinity property of resulting Bi2O3 powder has also been tested with XRD and morphology properties were tested with SEM. Meanwhile, photocatalytic properties were tested by using it to degrade Rhodamine B under sunlight. Results of XRD tests show that differences in sintering temperature affect crystallite size. Increases in sintering temperature between 400o C and 500o C result in greater crystallite size, whereas sintering temperature between 550o C and 600oC result in smaller crystallite size. Results of SEM tests show that resulting Bi2O3 has rod-like structure, While results of degradation tests show that increases in sintering temperature enhances photocatalytic activities of Bi2O3, as evident with Bi2O3 undergoing sintering at 600oC was able to degrade Rhodamine B with 56.74% effectiveness and degradation rate of 0.007 ppm/min.


2019 ◽  
Vol 56 ◽  
pp. 142-151
Author(s):  
Hassan Shokry ◽  
Marwa Elkady ◽  
Hesham Hamad

Nano sized ZrO2 nanopowder was synthesized by precipitation method. Phase transformation was investigated as a function of calcination temperature by XRD, SEM , and FT-IR. It is indicated that the thermal anneling from 400 to 800 °C resulted in increasing the average crystallite size from 12 to 20 nm. As the calcination temperature increased, the crystallite size and the agglomeration were increased. The increase in the monoclinic content and grain growth are caused by the calcination temperatures even calcination at 800 °C.


2021 ◽  
Vol 18 (18) ◽  
Author(s):  
Jemibha PAULDURAI ◽  
Ahila Mudisoodum PERUMAL ◽  
Dhanalakshmi JEYARAJA ◽  
Panimaya Valan Rakkini AMAL

The aim of this work is to synthesis CuO nanoparticles and investigates their eminent properties to identify their diverse application capability in the field of solar cells.  In this work, CuO nanoparticles were synthesized by precipitation method using Copper (II) nitrate and Copper (II) chloride. Surface effects due to defects, structural properties related through lattice parameter, and crystallite sizes of nanoparticles have been identified from XRD. The crystal plane and reflection peak position was calculated using Bragg’s law. It showed that CuO nanoparticles have a monoclinic structure, and that the average crystallite size of CuO nanoparticles was 28.82 nm. n-type semiconductor behavior had a direct band of Eg = 1.465(2) eV, analyzed from optical studies by DRS. The band gap of the sample was determined from the reflectance spectra using Kubelka-Munk (K-M) function. Elements present were found through absorption peak of FTIR. The blue shifts observed in FTIR spectra in CuO nanoparticles were compared with that of bulk CuO, and absorption band agreed with XRD results.  Morphological studies revealed the formation of spherical flake-shaped formation of CuO. It had a higher surface area and was well-suited to solar cell applications. HIGHLIGHTS The CuO nanoparticles were synthesized by precipitation method The average crystallite size of CuO nanoparticles obtained in the range of 28.82 nm Spherical flake-shaped nanostruture with higher surface area formed in this method Optical property of CuO (Eg = 1.465 eV) and good electron mobility make it a suitable solar cell absorber material GRAPHICAL ABSTRACT


2017 ◽  
Vol 728 ◽  
pp. 215-220 ◽  
Author(s):  
Natpasit Chaithanatkun ◽  
Korakot Onlaor ◽  
Benchapol Tunhoo

In the present work, the precipitation method was applied to prepare zinc oxide nanoparticles in the presence of zinc nitrate and potassium hydroxide as precursor solutions. The influence of annealing temperature on the properties such as structural and morphological of zinc oxide nanoparticles were performed by X-ray diffraction technique, field-emission scanning electron microscopy, Fourier-transform infrared spectroscopy, and Raman spectroscopy. The effects of annealing temperature on the crystallite size of zinc oxide nanoparticles have investigated. The XRD results represented that the zinc oxide nanoparticles exhibits high crystallinity of hexagonal wurtzite crystal structure. The average crystallite size of nanoparticles increased from 18 to 31 nm when the annealing temperature had increased. The morphology images show that the nanoparticles in this work were spherical in shape. Raman and FT-IR spectra confirm that the quality of Zn-O vibrational mode is stronger at higher annealing temperature.


2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Yao-Tung Lin ◽  
Chih-Huang Weng ◽  
Hui-Jan Hsu ◽  
Yu-Hao Lin ◽  
Ching-Chang Shiesh

The synergistic effect of nitrogen content and calcinations temperature on the N-doped TiO2catalysts prepared by sol-gel method was investigated. The phase and structure, chemical state, optical properties, and surface area/pore distribution of N-doped TiO2were characterized using X-ray diffraction spectrometer, high-resolution transmission electron microscope, X-ray photoelectron spectroscopy, UV-vis diffusion reflectance spectroscopy, and Brunauer-Emmett-Teller specific surface area. Finding showed that the photocatalytic activity of N-doped TiO2was greatly enhanced compared to pure TiO2under visible irradiation. N dopants could retard the transformation from anatase to rutile phase. Namely, N-doping effect is attributed to the anatase phase stabilization. The results showed nitrogen atoms were incorporated into the interstitial positions of the TiO2lattice. Ethylene was used to evaluate the photocatalytic activity of samples under visible-light illumination. The results suggested good anatase crystallization, smaller particle size, and larger surface are beneficial for photocatalytic activity of N-doped TiO2. The N-doped TiO2catalyst prepared with ammonia to titanium isopropoxide molar ratio of 2.0 and calcinated at 400°C showed the best photocatalytic ability.


2012 ◽  
Vol 585 ◽  
pp. 110-114
Author(s):  
A. Chithambararaj ◽  
Arumugam Chandra Bose

Single phase hexagonal molybdenum oxide (h-MoO3) nanocrystals were successfully synthesized by solution based chemical precipitation method. The effect of mineralizer (KNO3 salt) on hexagonal phase, crystallite size, and surface morphologies of MoO3 was investigated by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) analysis. The XRD result indicates that the diffractograms exhibit characteristic hexagonal phase of MoO3. From the line broadening analysis, the average crystallite size was calculated and estimated. A less crystallite size of 34 nm was obtained in the presence of mineralizing agent KNO3 in comparison to without mineralizer (46 nm). The particle exhibits rod like morphology with perfect hexagonal cross-section and well faceted top and side surfaces. Further, the thermal and optical properties were studied by thermo gravimetric analysis (TGA) and diffuse reflectance spectroscopy (DRS) measurements. The weight loss due to decomposition of intercalated water and ammonia were observed. By TGA analysis, the mineralizer assisted sample shows higher phase stability with the phase transition temperature of 520 °C due to the incorporation of K+ in MoO3 structure. The optical band gap energy was calculated using Kubelka-Muck function and the values were found to be 3.11 eV and 2.97 eV for KNO3 assisted and non-assisted MoO3 samples respectively. The observed increase in optical band gap (Eg) for h-MoO3 synthesized in the presence of KNO3 was attributed to the size dependent optical properties.


2021 ◽  
Author(s):  
Muhamad D. Permana ◽  
◽  
Atiek R. Noviyanti ◽  
Putri R. Lestari ◽  
Nobuhiro Kumada ◽  
...  

Photocatalysis is a process of accelerating reactions that are assisted by energy from light irradiation. Titanium dioxide (TiO2) is one of the most widely developed photocatalysis materials, and is used because of its high catalytic activity, stability and very affordable. The most commonly used precursors of TiO2 are titanium butoxide (TBOT) and titanium tetraisopropoxide (TTIP). These variations in precursor can lead to phase difference in the formation of TiO2 crystals, which further improves its nature in the activity of photocatalysis. In this study, the sol-gel method was used to synthesize titanium dioxide nanoparticles from variations of TBOT and TTIP. Furthermore, the structure, crystallite size and band gap of TiO2 were determined by X-ray diffraction (XRD) and UV-vis reflectance spectroscopy (DRS). Subsequently, TiO2 photocatalytic activity was evaluated in phenol photodegradation as a contaminant model with UV irradiation. The results showed the structure synthesized from TBOT had a higher amount of anatase, higher crystallinity, smaller crystallite size, larger band gap, and better photocatalytic activity than those from TTIP. Furthermore, it was shown that TiO2 from TBOT had an efficiency of 147% greater than TiO2 P25 Degussa, while TiO2 from TTIP had 66% efficiency compared to TiO2 P25.


2018 ◽  
Vol 4 (5) ◽  
pp. 478-482
Author(s):  
L. Prakash ◽  
C. Tirupathi

Pure and rare-earth metal Gd doped SnO2-CuO nanoparticles were successfully prepared from the starting materials SnCl2, CuCl2 and doping element gadolinium nitrate. Pure and Gd doped SnO2-CuO were synthesized by co-precipitation method. The samples were characterized using X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), UV-Vis, SEM, EDX and dielectric studies. The XRD analysis reveals that the rare-earth metal Gd dopants were substituted into rutile SnO2-CuO nanoparticles. Pure SnO2-CuO nanoparticles have an average crystallite size of 15 nm and rare-earth metal Gd doped SnO2-CuO nanoparticles have 18 nm. The average crystallite size of the sample increases when dopant was used and XRD peak intensity also increases when compared to pure SnO2-CuO nanoparticles. The optical absorption measurements exposed the nanometric size of the materials influences the energy band gap. Optical band gap was found to be 5.08 eV for pure SnO2-CuO nanoparticles and 5.14 eV for Gd doped SnO2-CuO nanoparticles. Surface morphology of pure and Gd doped SnO2-CuO nanoparticles annealed at 400 °C shows that most of the particles are rod shaped and hence it may have better sensitivity. Dielectric constant and dielectric loss decrease with increasing frequency at 100 °C and 200 °C. Doped samples show larger dielectric properties than pure SnO2-CuO nanoparticles.


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