Tunable band gap of Bi3+-doped anatase TiO2 for enhanced photocatalytic removal of acetaminophen under UV-visible light irradiation

Abstract A series of Bi3+-doped TiO2 photocatalysts has been prepared via the propylene oxide (PO) assisted sol-gel method. The effect of Bi3+ doping on structural surface morphology and optical properties of the as-prepared photocatalysts was characterized using UV-Visible (UV-Vis) diffuse reflectance spectroscopy, X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Brunauer-Emmett-Teller for determination of the specific surface area and porosity, and X-ray photoelectron spectroscopy. Increasing the Bi3+ doping percentage up to 10 mole percent, resulted in all as-prepared photocatalysts exhibiting pure anatase phase upon calcination at 400 °C for 3 hours. A red shift in optical band gap measurements was observed with increasing Bi3+ ion percent doping, which led to extension of the photocatalysts' activity to the visible region. The enhanced photocatalytic activity for removal of the pharmaceutical compound acetaminophen under UV-Vis light irradiation was demonstrated by comparing bismuth doped as-prepared photocatalysts with pure TiO2 photocatalysts prepared under the same conditions. Based on experimental conditions, the highest activity was achieved using 10 mole percent Bi3+-doped photocatalyst, where over a period of 4 hours more than 98% acetaminophen removal was achieved.

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Curcumin Doped SiO2/TiO2 Nanocomposites for Enhanced Photocatalytic Reduction of Cr (VI) under Visible Light

Catalysts ◽

10.3390/catal10080942 ◽

2020 ◽

Vol 10 (8) ◽

pp. 942

Author(s):

Zhiying Yan ◽

Zijuan He ◽

Mi Li ◽

Lin Zhang ◽

Yao Luo ◽

...

Keyword(s):

Visible Light ◽

Visible Light Irradiation ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance Spectroscopy ◽

Anatase Phase ◽

Mesoporous Structure ◽

Band Gap Energy ◽

Photocatalytic Reduction ◽

Light Irradiation ◽

X Ray

In order to further improve the photocatalytic performance of the SiO2/TiO2 composite under visible light irradiation, curcumin-doped SiO2/TiO2 nanocomposites were synthesized via directly incorporating it into the structure of SiO2/TiO2 during the synthesis using an inexpensive and readily available natural pigment (curcumin) as doping agent. The physicochemical properties of SiO2/TiO2 nanocomposites were characterized in detail by X-ray diffraction, transmission electron microscopy, Fourier transform-infrared spectroscopy, N2 adsorption–desorption isotherms, X-ray photoelectron spectroscopy, and UV-vis diffuse reflectance spectroscopy. The results indicate that all SiO2/TiO2 nanocomposites exhibited an anatase phase with a typical mesoporous structure. It was found that the dope of curcumin in the SiO2/TiO2 composite could decrease the crystal size, slightly improve the specific surface areas, significantly enhance the visible light absorption, and effectively narrow the band gap energy from 3.04 to 10(eV). Compared with bare SiO2/TiO2, the curcumin-doped SiO2/TiO2 resulted in enhanced photocatalytic reduction activity for Cr(VI) under visible light irradiation, and the CTS (12) sample with the appropriate content of curcumin of 12 wt % shows the photocatalytic yield reaching 100% within 2.5 hours, which is larger than CT (12) without silica. This could be attributed to the curcumin doping and the synergetic effects of SiO2 and TiO2 in SiO2/TiO2 nanocomposites.

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Synthesis, Characterization, and Photocatalytic Evaluation of Manganese (III) Phthalocyanine Sensitized ZnWO4 (ZnWO4MnPc) for Bisphenol A Degradation under UV Irradiation

Nanomaterials ◽

10.3390/nano10112139 ◽

2020 ◽

Vol 10 (11) ◽

pp. 2139 ◽

Cited By ~ 1

Author(s):

Chukwuka Bethel Anucha ◽

Ilknur Altin ◽

Zekeriya Biyiklioglu ◽

Emin Bacaksiz ◽

Ismail Polat ◽

...

Keyword(s):

Bisphenol A ◽

Uv Irradiation ◽

Photoelectron Spectroscopy ◽

Photocatalytic Performance ◽

Diffuse Reflectance Spectroscopy ◽

Degradation Process ◽

X Ray Diffraction ◽

X Ray ◽

Uv Visible ◽

Adsorption Desorption

ZnWO4MnPc was synthesized via a hydrothermal autoclave method with 1 wt.% manganese (iii) phthalocyanine content. The material was characterized for its structural and morphological features via X-ray diffraction (XRD) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, transmission emission microscopy (TEM), scanning electron microscopy-Energy dispersive X-ray spectroscopy (SEM-EDX), N2 adsorption–desorption at 77K, X-ray photoelectron spectroscopy (XPS), and UV-visible/diffuse reflectance spectroscopy(UV-vis/DRS). ZnWO4MnPc photocatalytic performance was tested on the degradation of bisphenol A (BPA). The ZnWO4MnPc material removed 60% of BPA after 4 h of 365 nm UV irradiation. Degradation process improved significantly to about 80% removal in the presence of added 5 mM H2O2 after 4 h irradiation. Almost 100% removal was achieved after 30 min under 450 nm visible light irradiation in the presence of same concentration of H2O2. The effect of ions and humic acid (HA) towards BPA removal was also investigated.

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Preparation of Ni Doped ZnO-TiO2Composites and Their Enhanced Photocatalytic Activity

International Journal of Photoenergy ◽

10.1155/2014/893158 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Xiaowen Zou ◽

Xiaoli Dong ◽

Limei Wang ◽

Hongchao Ma ◽

Xinxin Zhang ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Diffuse Reflectance Spectroscopy ◽

Sol Gel ◽

Visible Region ◽

Hydroxyl Groups ◽

X Ray ◽

Surface Hydroxyl ◽

Simulated Solar Light ◽

Transmission Electron ◽

Doped Zno

Herein, Ni doped ZnO-TiO2composites were prepared by facile sol-gel approach and were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), X-ray photoelectron spectroscopy (XPS), and photoluminescence spectroscopy (PL). The results indicated that the Ni ions can be incorporated into the lattice of TiO2structure and replace Ti. The introduction of Ni expanded light absorption of TiO2to visible region, increased amount of surface hydroxyl groups and physically adsorbed oxygen (as the electronic scavenges), and then enhanced separation rate of photogenerated carriers. The photodegradation test of reactive brilliant blue (KN-R) under simulated solar light indicated that Ni doped ZnO-TiO2composites have better photocatalytic activities, as compared to those of TiO2and ZnO-TiO2.

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Fabrication of ZnS-Bi-TiO2Composites and Investigation of Their Sunlight Photocatalytic Performance

The Scientific World JOURNAL ◽

10.1155/2014/503895 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Xuewei Dong ◽

Fan Zhang ◽

Chuan Rong ◽

Hongchao Ma

Keyword(s):

Photoelectron Spectroscopy ◽

Diffuse Reflectance Spectroscopy ◽

Kinetic Constant ◽

Sol Gel ◽

Visible Region ◽

Xenon Lamp ◽

X Ray ◽

Photodegradation Efficiency ◽

Photogenerated Electrons ◽

Transmission Electron

The ZnS-Bi-TiO2composites were prepared by the sol-gel method and were characterized by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV-visible diffuse reflectance spectroscopy (UV-Vis DRS). It is found that the doped Bi as Bi4+/Bi3+species existed in composites, and the introducing of ZnS enhanced further the light absorption ability of TiO2in visible region and reduced the recombination of photogenerated electrons and holes. As compared to pure TiO2, the ZnS-Bi-TiO2exhibited enhanced photodegradation efficiency under xenon lamp irradiation, and the kinetic constant of methyl orange removal with ZnS-Bi-Ti-0.005 (0.0141 min−1) was 3.9 times greater than that of pure TiO2(0.0029 min−1), which could be attributed to the existence of Bi4+/Bi3+species, the ZnS/TiO2heterostructure.

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Noble metal-modified titania with visible-light activity for the decomposition of microorganisms

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.9.77 ◽

2018 ◽

Vol 9 ◽

pp. 829-841 ◽

Cited By ~ 11

Author(s):

Maya Endo ◽

Zhishun Wei ◽

Kunlei Wang ◽

Baris Karabiyik ◽

Kenta Yoshiiri ◽

...

Keyword(s):

Antibacterial Activity ◽

Visible Light ◽

Noble Metal ◽

Visible Light Irradiation ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance Spectroscopy ◽

Light Irradiation ◽

Localized Surface Plasmon ◽

Mycelium Growth ◽

X Ray

Commercial titania photocatalysts were modified with silver and gold by photodeposition, and characterized by diffuse reflectance spectroscopy (DRS), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy (STEM). It was found that silver co-existed in zero valent (core) and oxidized (shell) forms, whereas gold was mainly zero valent. The obtained noble metal-modified samples were examined with regard to antibacterial (Escherichia coli(E. coli)) and antifungal (Aspergillus niger(A. niger),Aspergillus melleus(A. melleus),Penicillium chrysogenum(P. chrysogenum),Candida albicans(C. albicans)) activity under visible-light irradiation and in the dark using disk diffusion, suspension, colony growth (“poisoned food”) and sporulation methods. It was found that silver-modified titania, besides remarkably high antibacterial activity (inhibition of bacterial proliferation), could also decompose bacterial cells under visible-light irradiation, possibly due to an enhanced generation of reactive oxygen species and the intrinsic properties of silver. Gold-modified samples were almost inactive against bacteria in the dark, whereas significant bactericidal effect under visible-light irradiation suggested that the mechanism of bacteria inactivation was initiated by plasmonic excitation of titania by localized surface plasmon resonance of gold. The antifungal activity tests showed efficient suppression of mycelium growth by bare titania, and suppression of mycotoxin generation and sporulation by gold-modified titania. Although, the growth of fungi was hardly inhibited through disc diffusion (inhibition zones around discs), it indicates that gold does not penetrate into the media, and thus, a good stability of plasmonic photocatalysts has been confirmed. In summary, it was found that silver-modified titania showed superior antibacterial activity, whereas gold-modified samples were very active against fungi, suggesting that bimetallic photocatalysts containing both gold and silver should exhibit excellent antimicrobial properties.

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Enhanced Visible Light Photocatalytic Activity of Mesoporous AnataseTiO2Codoped with Nitrogen and Chlorine

International Journal of Photoenergy ◽

10.1155/2012/593245 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 9

Author(s):

Xiuwen Cheng ◽

Xiujuan Yu ◽

Zipeng Xing ◽

Lisha Yang

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Band Gap ◽

Light Absorption ◽

Photoelectron Spectroscopy ◽

Sol Gel ◽

Visible Region ◽

X Ray ◽

Visible Light Photocatalytic Activity ◽

Visible Light Photocatalytic

Anatase mesoporous titanium dioxide codoped with nitrogen and chlorine (N-Cl-TiO2) photocatalysts were synthesized through simple one-step sol-gel reactions in the presence of ammonium chloride. The resulting materials were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible diffuse reflection spectrum (UV-vis DRS). XRD results indicated that codoping with nitrogen and chlorine could effectively retard the phase transformation of TiO2from anatase to rutile and the growth of the crystallite sizes. XPS revealed that nitrogen and chlorine elements were incorporated into the lattice of TiO2through substituting the lattice oxygen atoms. DRS exhibited that the light absorption of N-Cl-TiO2in visible region was greatly improved. As a result, the band gap of TiO2was reduced to 2.12 eV. The photocatalytic activity of the as-synthesized TiO2was evaluated for the degradation of RhB and phenol under visible light irradiation. It was found that N-Cl-TiO2catalyst exhibited higher visible light photocatalytic activity than that of P25 TiO2and N-TiO2, which was attributed to the small crystallite size, intense light absorption in visible region, and narrow band gap.

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Facile deposition of carbon-doped TiO2 films by two-electrode electrodeposition setup

Modern Physics Letters B ◽

10.1142/s021798492150175x ◽

2021 ◽

pp. 2150175

Author(s):

Necati Basman ◽

Mehmet Gokcen

Keyword(s):

Photoelectron Spectroscopy ◽

Diffuse Reflectance Spectroscopy ◽

Carbon Doping ◽

Silicon Substrates ◽

X Ray Diffraction ◽

High Carbon ◽

X Ray ◽

Carbon Doped ◽

Surface Areas ◽

Uv Visible

This study presents a simple electrochemical deposition route to obtain carbon-doped TiO2 films. The deposition of the films is carried out on silicon substrates from a mixture of methanol (CH3OH) and Titanium (IV) isopropoxide (Ti[OCH(CH3)2]4) solution using a simple two-electrode electrodeposition setup. The obtained films are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Visible diffuse reflectance spectroscopy (DRS) and conductivity measurements. Depending on the deposition conditions, both amorphous and crystalline TiO2 films could be obtained. It is found that carbon is doped both substitutionally and interstitially. High carbon doping (up to 18.96%) enables to obtain TiO2 film with narrowed bandgap and high conductivity to about 2.3 eV and [Formula: see text] S cm[Formula: see text], respectively. This study suggests that the proposed electrodeposition route offers an easy way of obtaining conductive and narrowed bandgap TiO2 films on large surface areas.

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Au/TiO2Reusable Photocatalysts for Dye Degradation

International Journal of Photoenergy ◽

10.1155/2013/752605 ◽

2013 ◽

Vol 2013 ◽

pp. 1-10 ◽

Cited By ~ 24

Author(s):

Silija Padikkaparambil ◽

Binitha Narayanan ◽

Zahira Yaakob ◽

Suraja Viswanathan ◽

Siti Masrinda Tasirin

Keyword(s):

Photoelectron Spectroscopy ◽

Diffuse Reflectance ◽

Diffuse Reflectance Spectroscopy ◽

Dye Degradation ◽

Analytical Techniques ◽

X Ray Diffraction ◽

X Ray ◽

Dye Pollutants ◽

Transmission Electron ◽

Uv Visible

Nanogold doped TiO2catalysts are synthesized, and their application in the photodegradation of dye pollutants is studied. The materials are characterized using different analytical techniques such as X-ray diffraction, transmission electron microscopy, UV-visible diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. The results revealed the strong interaction between the metallic gold nanoparticles and the anatase TiO2support. Au doped systems showed very good photoactivity in the degradation of dye pollutants under UV irradiation as well as in sunlight. A simple mechanism is proposed for explaining the excellent photoactivity of the systems. The reusability studies of the photocatalysts exhibited more than 98% degradation of the dye even after 10 repeated cycles.

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Preparation of BiXY(2-X)O3 and its Photocatalytic Degradation of Molasses Fermentation Wastewater under Visible-Light Irradiation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.287-290.1640 ◽

2011 ◽

Vol 287-290 ◽

pp. 1640-1645 ◽

Cited By ~ 5

Author(s):

Min Guang Fan ◽

Zu Zeng Qin ◽

Zi Li Liu ◽

Tong Ming Su

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Photocatalytic Degradation ◽

Visible Light Irradiation ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance ◽

Diffuse Reflectance Spectroscopy ◽

Active Oxygen Species ◽

Light Irradiation ◽

X Ray

A series of BixY(2-x)O3photocatalysts were successfully prepared by a solid-state reaction and were subsequently characterized by powder X-ray diffraction, UV-vis diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy (XPS). The UV-vis diffuse reflectance spectra revealed that the BixY(2-x)O3samples absorbed light in the visible-light range (400-800 nm). The XPS results indicated that active oxygen species were generated on the Bi1.8Y0.2O3surface, which displayed a higher photocatalytic activity. When using photocatalytic degradation molasses fermentation wastewater as a model reaction, the Bi1.8Y0.2O3showed higher photocatalytic activity in comparison to Bi0.2Y1.8O3under visible-light irradiation.

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Design and fabrication of Ag3VO4/g-C3N4 heterostructure photocatalyst for enhanced visible light degradation of various organic pollutants

10.21203/rs.3.rs-329610/v1 ◽

2021 ◽

Author(s):

N Sujatha ◽

M Meenachi ◽

S Mohammed Harshulkhanb ◽

H.H Hegazy

Keyword(s):

Electron Microscopy ◽

Visible Light ◽

Visible Light Irradiation ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance Spectroscopy ◽

Light Irradiation ◽

X Rays ◽

Hydrothermal Route ◽

X Ray ◽

Visible Light Degradation

Abstract In later years, numerous viable photocatalysts have been created in order to illuminate the issues of natural toxins. In this work, heterostructured photocatalysts Ag3VO4/g-C3N4 were prepared by effortless hydrothermal route in order to anchor Ag3VO4 on the surface of the g-C3N4 nanosheets. The prepared samples were fairly characterized using X-ray diffraction (XRD), Energy dispersive analysis of X-rays (EDAX), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (UV-DRS), photoluminescence, and X-ray photoelectron spectroscopy (XPS) techniques. The photocatalytic activity of the samples was evaluated by degrading malachite green (MG) and 2,4 dimethyl phenol (DMP) in aqueous solution under visible light irradiation. Compared with Ag3VO4 and g-C3N4, the heterojuncted photocatalyst 50 wt% Ag3VO4/g-C3N4 exhibits the best activity such as high degradation efficiency (99%), high apparent constant (0.0923 min− 1) and long term stability towards DMP under visible light irradiation. The development of a phase scheme heterojunction between Ag3VO4 and g-C3N4 improved the photocatalytic efficiency of Ag3VO4/g-C3N4 composites. Furthermore, the porous structure of g-C3N4 and the effect of Ag surface plasmon resonance (SPR) speed up the isolation and transfer of electron-hole pairs, reducing the likelihood of recombination.

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