scholarly journals Preparation and Properties of Floral CaO/ZnO Nanocomposite From Achatina Fulica Snail Shell

Author(s):  
Qiushi Jiang ◽  
Zhaolian Han ◽  
Yafeng Yuan ◽  
Zhiqiang Cheng

Abstract In this study, CaO prepared by calcination treatment from abandoned Achatina fulica shell was used as a raw material, and the nano-flower-like CaO/ZnO photocatalytic composite material was prepared through co-precipitation method. SEM study showed ZnO with spindle-like petals in the range of 500-1000 nm grown on the surface of CaO carrier. The mapping image shows that the base component of the nanometer flower is mainly CaO, which is because CaO is not only in the reaction as a carrier, but also creates an alkaline environment in the methanol system, which is advantageous for co-precipitation. UV-vis spectroscopy shows that the visible light absorption of composites has red shifts, besides, PL, EIS and photocurrent test showed that the composites have stronger electronic hole separation capabilities. The visible light degradation test of rhodamine B showed that CaO/ZnO photocatalytic composite could degrade 90% of the pollutants in 25 min, superior to CaO and ZnO, exhibiting recyclability properties, which is a potential candidate with cost-effective and sustainable photocatalysts.

2021 ◽  
pp. 1-16
Author(s):  
R. Kumari ◽  
H. Jaiswal ◽  
T. Chowdhury ◽  
A.K. Ghosh

Aflatoxin B1 (AFB1) is a most potent carcinogenic secondary metabolite produced by Aspergillus flavus. As a food safety concern, development of a rapid, cost effective, sensitive and easy to use method for the detection of aflatoxin is of prime requirement. In this study, AFB1 was conjugated with bovine serum albumin (BSA), and AFB1-BSA conjugate was purified by HPLC. Purification was confirmed by UV-Vis spectroscopy, FTIR and MALDI-TOF mass spectrometry. The polyclonal antibody was raised against AFB1-BSA conjugate in rabbit and purified by protein A sepharose and BSA sepharose affinity columns. Iron oxide nanoparticles (MNPs) were synthesised by co-precipitation method and their surface was functionalised with (3-aminopropyl) triethoxysilane (APTES). Size of APTES conjugated MNPs was determined by electron microscopy, and characterised by several biophysical techniques. The purified anti-AFB1 antibody was conjugated with surface functionalised MNPs and the conjugation was confirmed by determining the sizes of free and antibody conjugated MNPs by field emission scanning electron microscope where increase of particle sizes from 10-20 to 40-50 nm was observed due to antibody conjugation. Anti-AFB1 antibody conjugated MNPs were used for capturing AFB1 from the aflatoxin spiked wheat grains with a recovery percentage of more than 80% and used effectively five times. The captured AFB1 was then quantified by a sensitive colorimetric assay where colourless AFB1 was first converted into coumaric acid by NaOH. Subsequently, coumaric acid reacted with 2,6-dibromoquinone-4-chloroimide (DBQC) to a green-coloured indophenol product which was quantified spectrophotometrically. AFB1 contamination as low as 2 μg/kg in wheat grains was detected by the developed technique suggesting its potential application for both qualitative and quantitative analysis of aflatoxins present in feed and food materials.


Author(s):  
Jagath Retchahan Sivalingam ◽  
Fai Kait Chong ◽  
Cecilia Devi Wilfred

CeO2-TiO2 photocatalyst with Ce:Ti molar ratio of 1:9 was synthesized via co-precipitation method in the presence of 1-ethyl-3-methyl imidazolium octylsulfate, [EMIM][OctSO4] (CeO2-TiO2-IL). The ionic liquid acts as a templating agent for particle growth. The CeO2-TiO2 and TiO2 photocatalysts were also synthesized without any ionic liquid for comparison. Calcination was conducted on the as-synthesized materials at 400˚C for 2 h. The photocatalysts were characterized using diffuse reflectance UV-Vis spectroscopy (DR-UV-Vis), field emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), and surface area and pore size analyzer (SAP). The presence of CeO2 has changed the optical property of TiO2. It has extended the absorption edge of TiO2 from UV to visible region. The calculated band gap energy decreased from 2.82 eV (TiO2) to 2.30 eV (CeO2-TiO2-IL). The FESEM morphology showed that samples forms aggregates and the surface smoothens when ionic liquid was added. The average crystallite size of TiO2, CeO2-TiO2, and CeO2-TiO2-IL were 20.8 nm, 5.5 nm, and 4 nm. In terms of performance, photodegradation of 1000 ppm of diisopropanolamine (DIPA) was conducted in the presence of hydrogen peroxide (H2O2) and visible light irradiation which was provided by a 500 W halogen lamp. The best performance was displayed by CeO2-TiO2-IL calcined at 400˚C. It was able to remove 82.0% DIPA and 54.8% COD after 6 h reaction.  Copyright © 2018 BCREC Group. All rights reservedReceived: 26th July 2017; Revised: 22nd October 2017; Accepted: 29th October 2017; Available online: 22nd January 2018; Published regularly: 2nd April 2018How to Cite: Sivalingam, J.R., Kait, C.F., Wilfred, C.D. (2018). CeO2-TiO2 Photocatalyst: Ionic Liquid-Mediated Synthesis, Characterization, and Performance for Diisopropanolamine Visible Light Degradation. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1): 170-178 (doi:10.9767/bcrec.13.1.1396.170-178) 


2015 ◽  
Vol 3 (29) ◽  
pp. 15248-15258 ◽  
Author(s):  
N. Sabari Arul ◽  
D. Mangalaraj ◽  
R. Ramachandran ◽  
A. Nirmala Grace ◽  
Jeong In Han

Hybrid CeO2/Fe2O3 composite nanospindles (CNSs) are synthesized by a simple and cost effective co-precipitation method, utilized for wastewater treatment and energy storage applications.


2021 ◽  
Vol 21 (11) ◽  
pp. 5707-5713
Author(s):  
M. Ramachandran ◽  
R. Subadevi ◽  
P. Rajkumar ◽  
R. Muthupradeepa ◽  
R. Yuvakkumar ◽  
...  

In the present work, pure nanocrystalline monoclinic Zirconia (ZrO2) has been successfully synthesized and optimized by the modified co-precipitation method. The concentration of raw material has been optimized with the fixed amount of precipitation agent (Potassium hydroxide KOH). The thermal history of the precursor has been examined through TG/DTA analysis. All the samples are subjected to study the structure, fingerprints of the molecular vibrations, and morphology analyses. The representative sample has been analyzed through Transmission Electron Microscope (TEM) and X-ray Photo Electron Spectroscopy (XPS) analyses. The as-prepared sample exhibits the better crystallinity and surface morphology with lesser particle size (190 nm) when the raw material concentration is 0.2 M. The as-prepared ZrO2 filler (0, 3, 6, 9, and 12 wt.%) is spread through the enhanced polymer electrolyte P(S-MMA) (27 Wt.%)-LiClO4 (8 wt.%)-EC + PC (1;1 of 65 wt.%) complex system via solution casting method. The as-synthesized electrolyte films are examined via complex impedance analysis. P(S-MMA) (27 wt.%)-LiCIO4 (8 wt.%)-EC + PC (1 ;1 of 65 wt.%)-6 wt.% of ZrO2 shows the high ionic conductivity 2.35 × 10–3 Scm–1. Temperature-dependent ionic conductivity studies obey the non-linear behavior. The enhanced ZrO2 has been expected to enhance the other electrochemical properties of the lithium secondary battery.


2021 ◽  
Vol 1 (1) ◽  
pp. 1-14
Author(s):  
Muhammad Nur Iman Amir ◽  
Nurhidayatullaili Muhd Julkaplia ◽  
Saba Afzal

Titanium dioxide (TiO2) nanoparticles are used enormously for treating wastewater pollutants due to their unique optoelectronic and physiochemical properties. Though, wide bandgap, fast recombination of e- - h+ pair, and low adsorption toward organic pollutants limit their applications. However, immobilization of TiO2 on Chitosan (Cs) is believed to overcome these limitations. Cs with plenty of NH2 and OH groups in their structure are expected to enhance their adsorption and consequently photocatalytic performance. A series of TiO2/Cs photocatalysts have been prepared using a chemical co-precipitation method. Amount of TiO2 is varied from 0.25, 0.50, and 0.75 to 1.0 g. The photocatalysts are characterized by using FESEM-EDS, CHNS Elemental Analyser TGA, FTIR, and UV-Vis spectroscopy. These characterization results revealed the formation of a good interface between TiO2 and Cs matrix. Increasing TiO2 content significantly increased the thermal stability of the photocatalyst up to 600ᵒC. The photocatalytic activity of Cs/TiO2 is observed under UV light which is found to be more significant with 1:1(TiO2: Cs) composition for the degradation of methylene blue dye at 85 % and be maintained up to 4 numbers of cycles. This demonstrated open new insight into the application of Cs as a support materials and adsorption agent in TiO2 based photocatalyst system


2019 ◽  
Vol 967 ◽  
pp. 259-266 ◽  
Author(s):  
Muhammad Rizal Fahlepy ◽  
Yuyu Wahyuni ◽  
Muhamma Andhika ◽  
Arini Tiwow Vistarani ◽  
Subaer

This research is about nanoparticles hematite (NPH) synthesized and characterized from natural iron sands using co-precipitation method and its potential applications as extrinsic semiconductor materials type-N. The aims of this study is to determine the process parameters to obtain hematite of high purity degree and to observe its physical characteristics as an extrinsic semiconductor materials type-N. The iron sand was first separated by magnetic technique and then dissolved into HCl solution before conducting the precipitation process. Precipitation was done by dripping ammonium hydroxide (NH4OH). Precipitated powder was dried at 80°C for 2 hours, and then calcined at 500°C, 600°C 700°C for 2 hours respectively. The composition of iron sands, purity degree, hematite mineral grain size, and space group were analyzed by XRF, XRD, FTIR and SEM. The XRF analysis result of raw material, showed that dominant element and composition in the sample is Fe with purity degree is 90.51%. The XRD result before and after precipitation showed Fe3O4 and α-Fe2O3. Fe3O4 purity degree was obtained 85%, and α-Fe2O3 in NPH500, NPH600, NPH700 were 63%, 83%, and 76%, respectively. FTIR spectral showed crystalline hematite characteristics stong band of 472.07 to 559.62 cm-1. SEM image showed the morphology of agglomeration particulates, when the calcinaton temperature increases, the agglomeration will be seperated due to thermal energy. Based on the charaterization results it was found that the natural iron sand synthesized has the potential to be applied as an N-type extrinsic semiconductor material.


2011 ◽  
Vol 287-290 ◽  
pp. 1735-1743 ◽  
Author(s):  
Yi Dong Shi ◽  
Qiong Guo ◽  
Yuan Song Xie

The C, N, S tri-doped TiO2 with high visible-light photo-catalysis effect was successfully prepared by mixing thiourea with the self-prepared TiO2 powder through calcining for 2h at 450°C. The TiO2 powder was obtained by homogeneous precipitation method using the metatitanic acid instead of expensive chemical reagents contained Ti as raw material. The effect of doping materials and methods on the photo-degradation rate of methylene blue and dyes was studied. The characterizations of the doped TiO2 were analyzed using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-visible absorption spectra (UV-vis). The results showed that this sample was the anatase TiO2 and contained elements C, N, S. The sample exhibited a significant response to ultraviolet and visible light. In the photo-degradation experiment, the C, N, S, tridoped-TiO2 could decolorize methylene blue and textile dyes quickly, and the photo-degradation rate of methylene blue could reach upward 98% after 3 hours under the different light sources.


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