Visible-Light Driven LaNiO3 Nanosized Photocatalysts Prepared by a Sol-Gel Process

2011 ◽  
Vol 279 ◽  
pp. 83-87 ◽  
Author(s):  
Pei Song Tang ◽  
He Sun ◽  
Feng Cao ◽  
Jin Tian Yang ◽  
Sheng Liang Ni ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Visible Light ◽  
Light Absorption ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
High Photocatalytic Activity ◽  
Visible Light Absorption ◽  
Average Grain Size ◽  
Sol Gel Process

The LaNiO3 nanoparticles were prepared by a sol-gel process. The LaNiO3 nanoparticles were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Vis diffuse reflectance spectroscopy (DRS). XRD and SEM demonstrate the successful synthesis of single phase perovskite LaNiO3 and an average grain size of 80 nm in diameter. It was found that the as-prepared LaNiO3 shows strong visible-light absorption with absorption onset of 545 nm, indicating a narrow optical band gap of 2.28 eV. Consequently, LaNiO3 nanoparticles show high visible-light photocatalytic activity for decomposition of methyl orange in comparison with the commercial Degussa P25. The photocatalytic experiment shows the high photocatalytic activity for the decomposition of methyl orange under visible-light irradiation, which is attributed to the strong visible-light absorption.

scholarly journals Nickel and sulfur codoped TiO2 nanoparticles for efficient visible light photocatalytic activity

2021 ◽  
Author(s):  
Mehala Kunnamareddy ◽  
Ranjith Rajendran ◽  
Megala Sivagnanam ◽  
Ramesh Rajendran ◽  
Barathi Diravidamani
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Light Absorption ◽  
Fourier Transforms ◽  
Phase Particle ◽  
Energy Dispersive Spectrometer ◽  
Sol Gel ◽  
Bandgap Energy ◽  
Visible Light Absorption

AbstractIn this work, Nickel (Ni) and sulfur (S) codoped TiO2 nanoparticles were prepared by a sol-gel technique. The as-prepared catalyst was characterized using X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), FT-Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectra (DRS) for investigating crystal structure, crystal phase, particle size and bandgap energy of these samples. The photocatalytic performances of all the prepared catalysts have been investigated for the degradation of methylene blue (MB) under visible light irradiation. It was noticed that Ni-S codoped TiO2(Ni-S/TiO2) nanoparticles exhibited much higher photocatalytic activity compared with pure, Ni and S doped TiO2 due to higher visible light absorption and probable decrease in the recombination of photo-generated charges. It was decided that the great visible light absorption was created for codoped TiO2 by the formation of impurity energy states near both the edges of the collection, which works as trapping sites for both the photogenerated charges to decrease the recombination process.

Visible Light Absorption Characteristics of M-Nitrogen (M= Mn, Fe, Co, Ni, Cu) Co-Doped Monodisperse TiO2 Microparticles

2015 ◽  
Vol 1806 ◽  
pp. 19-24 ◽  
Author(s):  
John E. Mathis
Keyword(s):  
Photocatalytic Activity ◽  
Transition Metals ◽  
Visible Light ◽  
Light Absorption ◽  
Sol Gel ◽  
Percent Level ◽  
Wide Distribution ◽  
Electromagnetic Spectrum ◽  
Visible Light Absorption ◽  
Co Doping

ABSTRACTThere is great interest in improving TiO2’s photocatalytic activity in the visible portion of electromagnetic spectrum. Recent work has shown that co-doping mesoporous TiO2 microparticles with a transition metal and nitrogen, hereby designated as (M,N) TiO2, significantly increases its visible light absorption. However, the hydrothermal method used to produce the microparticles creates a wide distribution in the size of the microparticles, which could affect the absorption properties. Recently, it has become possible to produce monodisperse, mesoporous TiO2 microparticles with engineered sizes using a hybrid sol-gel/hydrothermal technique. Further, it has also been shown that the size of monodisperse TiO2 microparticles affects the the photocatalytic activity.This study investigated whether using mondodisperse (M,N) TiO2 microparticles would further increase visible-light absorption for (M,N)TiO2. The first-row transition metals chosen for this study - Mn, Fe, Co, Ni, and Cu – have been characterized in the earlier (M,N) TiO2 UV-vis study, which was used as a baseline. The doping levels of the transition metals samples were set at the 2.5 percent level previously shown to be optimum for photocatalytic activity.

Synthesis of Nanocrystalline InVO4 by Hydrothermal Process and its Visible-Light Photocatalytic Activity

2011 ◽  
Vol 284-286 ◽  
pp. 734-737 ◽  
Author(s):  
Pei Song Tang ◽  
Hai Feng Chen ◽  
Feng Cao ◽  
Guo Xiang Pan ◽  
Kun Yan Wang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Light Absorption ◽  
Diffuse Reflectance Spectroscopy ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
Visible Light Absorption ◽  
Visible Light Photocatalytic Activity ◽  
Hydrothermal Approach ◽  
Visible Light Photocatalytic

Monophasic orthorhombic InVO4 was synthesized using InCl3 and NH4VO3 as starting materials by a hydrothermal approach. The as-prepared InVO4 product was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). It was found that the as-prepared InVO4 shows strong visible-light absorption with absorption onset of 515 nm, indicating a narrow optical band gap of 2.4 eV. Furthermore, the as-prepared InVO4 shows high visible-light photocatalytic activity for decomposition of methyl orange, which is ascribed to the strong visible-light absorption.

Preparation YbFeO3 by Microwave Assisted Method and its Visible-Light Photocatalytic Activity

2013 ◽  
Vol 699 ◽  
pp. 708-711 ◽  
Author(s):  
Ling Xiang Jia ◽  
Jun Yue Zhu ◽  
Ting Ting Lin ◽  
Zhen Jiang ◽  
Chao Wan Tang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
High Photocatalytic Activity ◽  
Raw Material ◽  
X Ray Diffraction ◽  
Microwave Assisted ◽  
Average Grain Size ◽  
Uv Visible ◽  
Microwave Assisted Method

Using Yb(NO3)3•6H2O and Fe(NO3)3•9H2O as raw material, the YbFeO3 nanoparticles were synthesized by microwave assisted method. The YbFeO3 nanoparticles were characterized by thermogravimetry and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). It was found that the prepared YbFeO3 show an average grain size of 80 nm in diameter, and strong visible-light absorption with absorption onset of 608 nm, indicating a narrow optical band gap of 2.04eV. Consequently, the YbFeO3 nanoparticles show high photocatalytic activity for decomposition of methylene blue under visible-light irradiation.

Enhanced visible light absorption and photocatalytic activity of [KNbO3]1−x[BaNi0.5Nb0.5O3−δ]x synthesized by sol–gel based Pechini method

RSC Advances ◽  
2016 ◽  
Vol 6 (85) ◽  
pp. 82409-82416 ◽  
Author(s):  
Ping Wu ◽  
Guoming Wang ◽  
Ruizhi Chen ◽  
Yixin Guo ◽  
Xueming Ma ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Low Temperature ◽  
Visible Light ◽  
Light Absorption ◽  
Photocatalytic Performance ◽  
Pechini Method ◽  
Sol Gel ◽  
Visible Light Absorption ◽  
Gel Method ◽  
Visible Light Photocatalytic

[KNbO3]1−x[BaNi0.5Nb0.5O3−δ]x were synthesized by Pechini sol–gel method at low temperature. Visible light photocatalytic performance of this material was evaluated.

Effect of Chromium Doping on Visible Light Absorption of Nanosized Titania Sol-Gel

2009 ◽  
Vol 5 ◽  
pp. 95-104 ◽  
Author(s):  
J.A. Pedraza-Avella ◽  
R. López ◽  
F. Martínez-Ortega ◽  
E.A. Páez-Mozo ◽  
Ricardo Gómez
Keyword(s):  
Visible Light ◽  
Light Absorption ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Anatase Phase ◽  
Sol Gel ◽  
Visible Light Absorption ◽  
X Ray ◽  
Chromium Doping ◽  
Doped Titania

Visible light absorption of TiO2 can be induced by the addition of transition metal impurities. However, many dissimilar results have been reported about this subject and there are various interpretations about the origin of these absorption features. In this work, samples of chromium-doped titania (TiO2-Cr) with different dopant contents (0.1, 0.5, 1.0 and 5.0 wt. %) were prepared by a sol-gel method. Their particle size was determined by dynamic light scattering and it was on the nanometer scale (18 nm). X-ray powder diffraction and Raman spectroscopy showed only the presence of anatase phase in all samples. X-ray photoelectron spectroscopy reveals that the oxidation state of chromium in the prepared materials is different than in the dopant precursor. This change can be associated to the oxidative gelling conditions used in the materials preparation. UV VIS diffuse reflectance spectroscopy showed that the chromium doping, until 1.0 wt. %, did not effectively narrow the TiO2 band-gap but it induces the visible light absorption probably through the formation of color centers.

Preparation of Nanosized Ni2+-Doped ErFeO3 by Microwave Assisted Process and its Visible-Light Photocatalytic Activity

2017 ◽  
Vol 748 ◽  
pp. 418-422 ◽  
Author(s):  
Li Fang ◽  
Qian Yang ◽  
Meng Ying Xu ◽  
Jun Wei Cao ◽  
Pei Song Tang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
Raw Materials ◽  
Doping Amount ◽  
Illumination Time ◽  
Visible Light Photocatalyst ◽  
Microwave Assisted ◽  
Average Grain Size

Using Er (NO3)3·6H2O, Fe (NO3)3·9H2O, Ni (NO3)3·6H2O as main raw materials, the nanosized Ni2+-doped ErFeO3 was prepared by microwave assisted method. The Ni2+-doped ErFeO3 samples were characterized by thermogravimetry and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). The different doping amount was studied for photocatalytic properties of samples. The results show that the Ni2+-doped ErFeO3 is perovskite structure (ABO3), and its average grain size is nearly 80nm. Under the visible-light, using the methyl-orange as simulate sewages, the Ni2+-doped ErFeO3 has higher photocatalytic activity than pure ErFeO3 powder, and the doping amount of 0.02 to ErFeO3 is the best. When the illumination time of the visible light is 120 min, the degradation rate of the best ratio of the samples can rise to nearly 100% for the decomposition of methyl orange. Therefore, the nanosized Ni2+-doped ErFeO3 is an excellent visible-light photocatalyst.

Characterization and Photocatalytic Activity of SmMnO3 Prepared by Sol-Gel Process

2017 ◽  
Vol 748 ◽  
pp. 403-407
Author(s):  
Jia Yuan Min ◽  
Long Long Yu ◽  
Pei Song Tang ◽  
Hai Feng Chen
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Uv Light ◽  
Raw Materials ◽  
Sol Gel ◽  
Average Particle Size ◽  
High Photocatalytic Activity ◽  
Average Particle ◽  
Nitrate Hexahydrate ◽  
Sol Gel Process

Using samarium (III) nitrate hexahydrate, manganese nitrate and citric acid as main raw materials, the SmMnO3 gel was prepared by sol-gel process. The gel was kept at 100 °C for 24 h to get the xerogel. Then, the xerogel was respectively calcined in muffle furnace at 600 °C, 700 °C, 800 °C and 900 °C. The structure and morphology of samples were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier Transform Infrared (FT-IR) spectroscopy. The UV photocatalytic activities of SmMnO3 were investigated by methyl orange which was used as simulated sewage. The results show that the pure SmMnO3 can be obtained through calcination between 700 °C and 800 °C, and the SmMnO3 have an average particle size of 80 nm. The SmMnO3 samples calcined at 700 °C and 800 °C show high photocatalytic activity for decomposition of methyl orange under UV-light irradiation. The SmMnO3 samples are consistent with first-order kinetics for the degradation of methyl orange. And the apparent rate constants are respectively k700 =0.01206 min-1and k800=0.01088 min-1.

Impact of Rutile Fraction on TiO2 Visible-Light Absorption and Visible-Light-Induced Photocatalytic Activity

2018 ◽  
Author(s):  
David Maria Tobaldi ◽  
Luc Lajaunie ◽  
ana caetano ◽  
nejc rozman ◽  
Maria Paula Seabra ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Light Absorption ◽  
Solid Phase ◽  
Diffraction Method ◽  
Band Alignment ◽  
Quantitative Phase Analysis ◽  
Transmission Microscopy ◽  
Visible Light Absorption ◽  
X Ray

<div>Titanium dioxide is by far the most utilised semiconductor material for photocatalytic applications. Still, it is transparent to visible-light. Recently, it has been proved that a type-II band alignment for the rutile−anatase mixture would improve its visible-light absorption.</div><div>In this research paper we thoroughly characterised the real crystalline and amorphous phases of synthesised titanias – thermally treated at different temperatures to get distinct ratios of anatase-rutile-amorphous fraction – as well as that of three commercially available photocatalytic nano-TiO2. </div><div>The structural characterisation was done via advanced X-ray diffraction method, namely the Rietveld-RIR method, to attain a full quantitative phase analysis of the specimens. The microstructure was also investigated via an advanced X-ray method, the whole powder pattern modelling. These methods were validated combining advanced aberration-corrected scanning transmission microscopy and high-resolution electron energy-loss spectroscopy. The photocatalytic activity was assessed in the liquid- and gas-solid phase (employing rhodamine B and 4-chlorophenol, and isopropanol, respectively, as the organic substances to degrade) using a light source irradiating exclusively in the visible-range.</div><div>Optical spectroscopy showed that even a small fraction of rutile (2 wt%) is able to shift to lower energies the apparent optical band gap of an anatase-rutile mixed phase. But is this enough to attain a real photocatalytic activity promoted by merely visible-light?</div><div>We tried to give a reply to that question.</div><div>Photocatalytic activity results in the liquid-solid phase showed that a high surface hydroxylation led to specimen with superior visible light-induced catalytic activity (i.e. dye and ligand-to-metal charge transfer complexes sensitisation effects). That is: not photocatalysis <i>sensu-strictu</i>.</div><div>On the other hand, the gas-solid phase results showed that a higher amount of the rutile fraction (around 10 wt%), together with less recombination of the charge carriers, were more effective for an actual photocatalytic oxidation of isopropanol.</div>

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