Solar-Photocatalytic Degradation of Waste from CO2 Removal System Using Metal Doped TiO2 Photocatalysts: Effect of TiO2 Support

2016 ◽  
Vol 1133 ◽  
pp. 532-536 ◽  
Author(s):  
Nadia Riaz ◽  
Mohamad Azmi Bustam ◽  
Sami Ullah ◽  
Ali E.I. Elkhalifah ◽  
Girma Gonfa ◽  
...  

The wastewater containing the spent alkanolamines and its derivatives emerging from the natural gas industries into water has become a critical concern. In the present study, Titanium dioxides was used as photocatalysts to investigate for their efficiency for the photodegradation of Diisopropanolamine (DIPA) containing wastewater under the visible light irradiation. DIPA was used as a model alkanolamine while different commercially available TiO2 were tested for photodegradation of DIPA under the visible light source. The physico-chemical properties of the prepared photocatalysts were analyzed using different characterization techniques including X-ray diffraction (XRD), Raman spectroscopy and N2-physisorption (BET).

Author(s):  
Snehamol Mathew ◽  
Priyanka Ganguly ◽  
Stephen Rhatigan ◽  
Vignesh Kumaravel ◽  
Ciara Byrne ◽  
...  

Indoor surface contamination by microbes is a major public health concern. A damp environment is one potential sources for microbe proliferation. Smart photocatalytic coatings on building surfaces using semiconductors like titania (TiO<sub>2</sub>) can effectively curb this growing threat.<b> </b>Metal-doped titania in anatase phase has been proved as a promising candidate for energy and environmental applications. In this present work, the antimicrobial efficacy of copper (Cu) doped TiO<sub>2 </sub>(Cu-TiO<sub>2</sub>) was evaluated against <i>Escherichia coli</i> (Gram-negative) and <i>Staphylococcus aureus</i> (Gram-positive) under visible light irradiation. Doping of a minute fraction of Cu (0.5 mol %) in TiO<sub>2 </sub>was carried out <i>via</i> sol-gel technique. Cu-TiO<sub>2</sub> further calcined at various temperatures (in the range of 500 °C – 700 °C) to evaluate the thermal stability of TiO<sub>2</sub> anatase phase. The physico-chemical properties of the samples were characterised through X-ray diffraction (XRD), Raman spectroscopy, X-ray photo-electron spectroscopy (XPS) and UV-visible spectroscopy techniques. XRD results revealed that the anatase phase of TiO<sub>2</sub> was maintained well, up to 650 °C, by the Cu dopant. UV-DRS results suggested that the visible light absorption property of Cu-TiO<sub>2 </sub>was enhanced and the band gap is reduced to 2.8 eV. Density functional theory (DFT) studies emphasises the introduction of Cu<sup>+</sup> and Cu<sup>2+</sup> ions by replacing Ti<sup>4+</sup> ions in the TiO<sub>2</sub> lattice, creating oxygen vacancies. These further promoted the photocatalytic efficiency. A significantly high bacterial inactivation (99.9%) was attained in 30 mins of visible light irradiation by Cu-TiO<sub>2</sub>.


2013 ◽  
Vol 832 ◽  
pp. 589-595 ◽  
Author(s):  
N.A. Edama ◽  
A. Sulaiman ◽  
K.H. Ku Hamid ◽  
M.N. Muhd Rodhi ◽  
Mohibah Musa ◽  
...  

This study analyzed the effects of sulphuric acid (H2SO4) treatment on pysico-chemical properties and morphological changes of clay obtained from Sg. Sayong, Perak. The clay was ground and sieved to <150μm and treated with different concentrations of H2SO4. The treatment was completed by refluxing the clay with different concentration of H2SO4 (1M, 5M and 10M ) at 100 °C for 4 hours and followed by calcination at 500 °C for 1 hour. The physic-chemical properties and morphological changes of the untreated and treated clay were compared using Surface Area Analyser, X-Ray Diffraction (XRD), Field Emission Scanning Electron Micrograph (FESEM), X-Ray Diffraction (XRD) and Fourier Transformed Infrared Spectroscopy (FTIR). The results showed that acid treatment of 5M increased the surface area from 25 m2/g to 75 m2/g and the pore volume increased from 0.1518 cc/g to 0.3546 cc/g. The nanopore size of the clay decreased from 24.8 nm to 19.4 nm after treated with acid. This can be explained due to the elimination of the exchangeable cations and generation of microporosity. The results of XRF showed SiO2 increased from 58.34% to 74.52% and Al2O3 reduced from 34.6% to 18.31%. The mineral oxides such as Fe2O3, MgO, CaO, K2O and TiO2 also reduced. This concluded that H2SO4 treatment has led to significant removal of octahedral Al3+, Fe3+ cations and other impurities. In conclusion, this study showed the physico-chemical properties and morphology of Sayong clay were improved once treated with H2SO4 and therefore suggests better supporting material for enzyme immobilization.


2014 ◽  
Vol 787 ◽  
pp. 35-40 ◽  
Author(s):  
Xiao Yan Zhou ◽  
Peng Wei Zhou ◽  
Hao Guo ◽  
Bo Yang ◽  
Ru Fei Ren

The p-n junction photocatalysts, p-CuO (at. 0-25%)/n-ZnO nanocomposite were prepared through hydrothermal method without using any organic solvent or surfactant. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-Ray spectroscopy, and UV-vis spectroscopy. The results demonstrated that the CuO/ZnO nanocomposite presented a two-dimensional morphology composed of sheet-like ZnO nanostructures adorned with CuO nanoparticles. The photocatalytic activity of CuO/ZnO with different Cu/Zn molar rations and pure ZnO synthesized by the identical synthetic route were evaluated by degrading methylene blue (MB) dye under UV-visible light irradiation. The CuO/ZnO with Cu/Zn molar ratio of 4% exhibits the highest photocatalytic activity compared that of the other photocatalysts under the identical conditions. It is mainly attributed to the increased charge separation rate in the nanocomposite and the extended photo-responding range.


2010 ◽  
Vol 75 (11) ◽  
pp. 1139-1148 ◽  
Author(s):  
Dmitry S. Perekalin ◽  
Evgeniya A. Trifonova ◽  
Ivan V. Glukhov ◽  
Josef Holub ◽  
Alexander R. Kudinov

Reaction of the tricarbollide anion [7,8,9-C3B8H11]– (1a) with the naphthalene complex [CpRu(C10H8)]+ under visible light irradiation in CH2Cl2 gives the 12-vertex closo-ruthenacarborane 1-Cp-1,2,3,5-RuC3B8H11 (2; 87% yield). This complex was also obtained by reaction of 1a with CpRu(cod)Cl (97%). Upon heating at 80 °C in toluene 2 rearranges into isomer 1-Cp-1,2,4,10-RuC3B8H11 (3; 63%). Irradiation of 1a with [CpRu(C10H8)]+ in acetone gives the 11-vertex closo-1-Cp-1,2,3,4-RuC3B7H10 (4; 32%). The latter was also prepared by reaction of 1a with [CpRu(MeCN)3]+ (59%). Compound 2 slowly undergoes cage contraction in acetone giving 4. Irradiation of 1a with [Cp*Ru(C10H8)]+ affords the isomeric 12-vertex closo-ruthenacarboranes 1-Cp*-1,2,3,5-RuC3B8H11 and 1-Cp*-1,2,4,10-RuC3B8H11 (2.2:1 ratio; 56%). Reaction of the amino-substituted tricarbollide anion [7-tBuNH-7,8,9-C3B8H10]– with [(C5R5)Ru(C10H8)]+ (R = H, Me) selectively gives 12-vertex closo-ruthenacarboranes 1-(C5R5)-12-tBuNH-1,2,4,12-RuC3B8H10 (ca. 50%). The structures of 2 and 4 were confirmed by X-ray diffraction.


2021 ◽  
Vol 1035 ◽  
pp. 1043-1049
Author(s):  
Di Xiang ◽  
Chang Long Shao

A simple route has been developed for the synthesis of Ag2O/ZnO heterostructures and the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and photoluminescence (PL) spectroscopy analysis. Considering the porous structure of Ag2O/ZnO, the photocatalytic degradation for the organic dyes, such as eosin red (ER), methyl orange (MO), methylene blue (MB) and rhodamine B (RhB), under visible light irradiation was investigated in detail. Noticeably, Ag2O/ZnO just took 40 min to degrade 96 % MB. The rate of degradation using the Ag2O/ZnO heterostructures was 2.3 times faster than that of the bare porous ZnO nanospheres under visible light irradiation due to that the recombination of the photogenerated charge was inhibited greatly in the p-type Ag2O and n-type ZnO semiconductor. So the Ag2O/ZnO heterostuctures showed the potential application on environmental remediation.


2011 ◽  
Vol 364 ◽  
pp. 238-242 ◽  
Author(s):  
Kimi Melody ◽  
Yuliati Leny ◽  
Mustaffa Shamsuddin

A series of In0.1SnxZn0.85-2xS solid solutions was synthesized by hydrothermal method and employed as photocatalyst for photocatalytic hydrogen evolution under visible light irradiation. The structures, optical properties and morphologies of the solid solutions were studied by X-ray diffraction, diffuse reflectance UV–visible spectroscopy and field emission scanning electron microscopy. From the characterizations, it was confirmed that In0.1SnxZn0.85-2xS solid solution can be obtained and they have nanosized particles. The highest photocatalytic activity was observed on In0.1Sn0.03Zn0.79S photocatalyst, with average rate of hydrogen production 3.05 mmol/h, which was 1.2 times higher than the In0.1Zn0.85S photocatalyst.


2019 ◽  
Vol 12 (06) ◽  
pp. 1950085 ◽  
Author(s):  
Di Zhao ◽  
Xuezheng An ◽  
Yaxian Sun ◽  
Guihua Li ◽  
Hongyan Liu ◽  
...  

p-n heterojunction Ag2CO3/Ag3PO4/Ni thin films were prepared by electrochemical co-deposition. The surface morphology and structural properties of the thin films were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). The photocatalytic (PC) properties of the Ag2CO3/Ag3PO4/Ni composite thin films were investigated by their ability to degrade rhodamine B (RhB) and Congo red (CR) under visible light irradiation. The results showed that the photodegradation efficiency of RhB by an Ag2CO3/Ag3PO4/Ni thin film under visible-light irradiation for 30[Formula: see text]min (98.84%) was 2.64 times higher than that of an Ag3PO4/Ni thin film and 3.44 times higher than of an Ag2CO3/Ni thin film. The presence of a [Formula: see text]-[Formula: see text] heterojunction greatly increased the charge conductivity of the film and its ability to photocatalytically reduce dissolved oxygen, which are the main reasons for the improved PC performance of the Ag2CO3/Ag3PO4/Ni films.


2019 ◽  
Vol 9 (13) ◽  
pp. 2598 ◽  
Author(s):  
M. J. Hernández-Rodríguez ◽  
R. Santana Rodríguez ◽  
R. Darias ◽  
O. González Díaz ◽  
J. M. Pérez Luzardo ◽  
...  

In this study, mortar specimens were prepared with a cement:sand:water ratio of 1:3:0.5, in accordance with standard EN196-1. Portland CEM I 52.5 R grey (G) and white (W) cements were used, together with normalised sand and distilled water. Different amounts of TiO2 photocatalyst were incorporated in the preparation of the mortar samples. The effect of the addition of TiO2 was studied on mechanical properties of the mortar and cement including compressive and flexural strength, consistency (the flow table test), setting time and carbonation. Characterization techniques, including thermogravimetry, mercury porosimetry and X-ray diffraction spectroscopy (XRD), were applied to study the physico-chemical properties of the mortars. It was shown that adding the photocatalyst to the mortar had no negative effect on its properties and could be used to accelerate the setting process. Specimen photoactivity with the incorporated photocatalyst was tested for NOx oxidation in different conditions of humidity (0% RH and 65% RH) and illumination (Vis or Vis/UV), with the results showing an important activity even under Vis radiation.


TAPPI Journal ◽  
2019 ◽  
Vol 18 (01) ◽  
pp. 21-27 ◽  
Author(s):  
Xueqing Qiu ◽  
Yingzhi Ma ◽  
Dafeng Zheng

A magnetic lignin-based nanomaterial (MLN) was prepared from alkaline lignin through an amination and precipitation strategy and characterized with Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TG), Brunauer-Emmett-Teller (BET) method, scanning electron microscope (SEM), dynamic light scattering (DLS), and vibrating sample magnetometer (VSM). The results illustrated that MLN was thermostable and had an extensive degree of aminated lignin coating. The specific surface area of MLN was 65.43 m2/g, with the total pore volume of 0.311 cm3/g. The zeta potential of MLN was positive when pH was less than 2.9, and the saturation magnetization was 50.8 emu/g. The characterization data discovered that the physico-chemical properties of MLN were helpful for the adsorption application.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Shaukat Ali Shahid ◽  
Ayman Nafady ◽  
Inam Ullah ◽  
Yun H. Taufiq-Yap ◽  
Imran Shakir ◽  
...  

High functional ZrFe2O5nanoparticles were synthesized using coprecipitation technique. The chemical composition of nanomaterials was studied by energy-dispersive X-ray (EDX). To observe the morphology, field emission scanning electron microscopy (FE-SEM) was used. X-ray diffraction (XRD) technique was utilized to appraise the structure of the synthesized material. The photocatalytic behavior of ZrFe2O5nano-particles was investigated by measuring the degradation rate of toluidine blue O (TBO) dye in aqueous solution in the presence of ZrFe2O5nano-particles under visible light irradiation. A steady decrease in absorption peak under visible light irradiation was observed by increasing exposure time. The degradation efficiency was observed as 92% after 140 min of exposure to visible light. Besides, ZrFe2O5nanophotocatalyst could be recovered and recycled easily. The rate of TBO and total organic carbon (TOC) removal under visible light irradiation decreased by only 5% and 10%, respectively, after seven cycles of use, demonstrating the high photostability of the synthesized nano-photocatalyst material.


Sign in / Sign up

Export Citation Format

Share Document