Bismuth Oxyhalides for NOx Degradation under Visible Light: The Role of the Chloride Precursor

Photocatalysis is a green technology for tackling water and air contamination. A valid alternative to the most exploited photocatalytic material, TiO2, is bismuth oxyhalides, which feature a wider bandgap energy range and use visible radiation to attain photoexcitation. Moreover, their layered structure favors the separation of photogenerated electron–hole pairs, with an enhancement in photocatalytic activity. Controlled doping of bismuth oxyhalides with metallic bismuth nanoparticles allows for further boosting of the performance of the material. In the present work, we synthesized Y%Bi-doped BiO(Cl0.875Br0.125) (Y = 0.85, 1, 2, 10) photocatalysts, using cetyltrimethylammonium bromide as the bromide source and varying the chloride source to assess the impact that both length and branching of the hydrocarbon chain might have on the framing and layering of the material. A change in the amount of the reducing agent NaBH4 allowed tuning of the percentage of metallic bismuth. After a thorough characterization (XRPD, SEM, TEM, UV-DRS, XPS), the photocatalytic activity of the catalysts was tested in the degradation of NOx under visible light, reaching a remarkable 53% conversion after 3 h of illumination for the material prepared using cetylpyridinium chloride.

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

Journal of Inorganic and Organometallic Polymers and Materials ◽

10.1007/s10904-021-01914-5 ◽

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.

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Fabrication of Novel Cyanuric Acid Modified g-C3N4/Kaolinite Composite with Enhanced Visible Light-Driven Photocatalytic Activity

Minerals ◽

10.3390/min8100437 ◽

2018 ◽

Vol 8 (10) ◽

pp. 437 ◽

Cited By ~ 7

Author(s):

Zhiming Sun ◽

Fang Yuan ◽

Xue Li ◽

Chunquan Li ◽

Jie Xu ◽

...

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Photocatalytic Performance ◽

Cyanuric Acid ◽

Degradation Mechanism ◽

Organic Pollutant ◽

Photogenerated Electron ◽

Light Illumination ◽

Acid Modification ◽

Visible Light Driven

A novel kind of cyanuric-acid-modified graphitic carbon nitride (g-C3N4)/kaolinite (m-CN/KA) composite with enhanced visible light-driven photocatalytic performance was fabricated through a facile two-step process. Rhodamine B (RhB) was taken as the target pollutant to study the photocatalytic performance of the synthesized catalysts. It is indicated that the cyanuric acid modification significantly enhanced photocatalytic activity under visible light illumination in comparison with the other reference samples. The apparent rate constant of m-CN/KA is almost 1.9 times and 4.0 times those of g-C3N4/kaolinite and bare g-C3N4, respectively. The superior photocatalytic performance of m-CN/KA could be ascribed, not only to the generation of abundant pore structure and reactive sites, but also to the efficient separation of the photogenerated electron-hole pairs. Furthermore, the possible photocatalytic degradation mechanism of m-CN/KA was also presented in this paper. It could be anticipated that this novel and efficient, metal-free, mineral-based photocatalytic composite has great application prospects in organic pollutant degradation.

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Photocatalytic Degradation of Methylene Blue and Methyl Orange by Y-PTC Metal-Organic Framework

Jurnal Kimia VALENSI ◽

10.15408/jkv.v7i2.22267 ◽

2021 ◽

Vol 7 (2) ◽

pp. 129-141

Author(s):

Adawiah Adawiah ◽

Muhammad Derry Luthfi Yudhi ◽

Agustino Zulys

Keyword(s):

Methylene Blue ◽

Photocatalytic Activity ◽

Methyl Orange ◽

Visible Light ◽

Visible Light Irradiation ◽

Metal Organic Framework ◽

Light Irradiation ◽

Bandgap Energy ◽

Metal Organic ◽

Organic Framework

The yttrium based metal-organic framework (MOF) Y-PTC was synthesized by the solvothermal method using perylene as the linker and yttrium as metal ion. This study aims to assess the photocatalytic activity of yttrium-perylenetetracarboxylate (Y-PTC) metal-organic framework (MOF) toward methylene blue and methyl orange under visible light irradiation. The results of the FTIR analysis showed that Y-PTC MOF had a different structure and composition from its precursor (Na4PTC). The Y-PTC MOF has a bandgap energy value of 2.20 eV with a surface area of 47.7487 m2/g. The SEM-EDS analysis showed an elemental composition of yttrium, carbon, and oxygen, were 6.9%, 72.1% and 20.7%, respectively. Furthermore, Y-PTC MOF was able to adsorb dyes at the optimum by 78.10% and 35.57% toward methylene blue (MB) and methyl orange (MO) at the dispersion period of 60 mins. Y-PTC MOF exhibited photocatalytic activity towards the degradation of methylene blue and methyl orange under visible light irradiation. The addition of H2O2 inhibited Y-PTC photocatalytic activity towards MO degradation from 50.89% to 26.38%. In contrast to MO, the addition of H2O2 had a positive effect on MB, which increased the degradation from 87.56% to 91.65%. Therefore, Y-PTC MOF possessed the potential of a photocatalyst material in dyes degradation under visible light irradiation.

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Cr Doped TiO2 Supported on TUD-1 Photocatalyst for Dye Photodegradation

Jurnal Teknologi ◽

10.11113/jt.v69.3209 ◽

2014 ◽

Vol 69 (5) ◽

Cited By ~ 3

Author(s):

Ooi Yee Khai ◽

Leny Yuliati ◽

Siew Ling Lee

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

High Surface ◽

Sol Gel ◽

High Surface Area ◽

Xrd Analysis ◽

Bandgap Energy ◽

Doped Tio2 ◽

Visible Light Driven ◽

Synthesized Materials

New visible light driven photocatalysts of 1 mol% Cr doped TiO2 supported on TUD-1 have been successfully synthesized. The Cr-TiO2/xTUD-1 (x = 10, 20, 30, 40 and 50) photocatalysts were prepared via surfactant-free sol-gel method followed by wet impregnation procedures. XRD analysis revealed that both TiO2 and Cr were incorporated in the highly porous siliceous matrix. FTIR analysis showed the existence of Si-O-Ti in all the materials. As observed, tetrahedral-coordinated Ti species were dominant in Cr-TiO2/10TUD-1, Cr-TiO2/20TUD-1 and Cr-TiO2/30TUD-1. Meanwhile, octahedral- coordinated Ti species were the dominant species in Cr-TiO2/40TUD-1 and Cr-TiO2/50TUD-1. It has been demonstrated that the amount of TUD-1 as photocatalyst support affected the wavelength response and the bandgap energy of the resulting materials. All the materials have bandgap energy of ~2.9 eV. The photocatalytic performance of the synthesized materials was tested out in dye photodegradation under visible light irradiation at 298 K for 5 hours. Results showed that all Cr-TiO2/TUD-1 materials had higher photocatalytic activity than that of Cr-TiO2. This could be explained by the high surface area and porosity provided by TUD-1 in enhancing the adsorption and diffusivities of the dye molecules, hence leading to the promising photocatalytic activity. Among the materials prepared, Cr-TiO2/30TUD-1 appeared as the most superior photocatalyst which gave the highest dye photodegradation.

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Synthesis of Er-doped Bi2WO6 and enhancement in photocatalytic activity induced by visible light

RSC Advances ◽

10.1039/c5ra19164e ◽

2015 ◽

Vol 5 (115) ◽

pp. 94887-94894 ◽

Cited By ~ 25

Author(s):

Meng Wang ◽

Ziyu Qiao ◽

Minghao Fang ◽

Zhaohui Huang ◽

Yan'gai Liu ◽

...

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Separation Efficiency ◽

Photogenerated Electron ◽

Electron Hole ◽

Er Doped

1.5% Bi2WO6:Er3+ exhibited highest photocatalytic activity as the separation efficiency of the photogenerated electron–hole pairs is enhanced.

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SORPTION AND PHOTOCATALYTIC ACTIVITY ZNCUO (X=0,05 AND 0,15) TO AS (III) IN AN ALKALINE MEDIUM

Physical and Chemical Aspects of the Study of Clusters Nanostructures and Nanomaterials ◽

10.26456/pcascnn/2020.12.792 ◽

2020 ◽

pp. 792-804

Author(s):

Ольга Ивановна Гырдасова ◽

Лилия Александровна Пасечник ◽

Владимир Николаевич Красильников ◽

Владимир Трофимович Суриков ◽

Михаил Владимирович Кузнецов

Keyword(s):

Solid Solution ◽

Photocatalytic Activity ◽

Visible Light ◽

Solid Solutions ◽

Photoelectron Spectroscopy ◽

Spectroscopy Data ◽

Visible Radiation ◽

X Ray ◽

Visible Light Range ◽

Doping Impurity

С использованием формиатогликолятных комплексов ZnCu(HCOO)(OCHCHO) (0 ≤ х ≤ 0,15) получены твердые растворы ZnCuO с 1D и композиты ZnCuO / CuO со сферической морфологией агрегатов соответственно. Материалы апробированы в реакции фотоокисления As(III) при воздействии ультрафиолетового и видимого излучения. Установлено, что медь является эффективной допирующей примесью в составе твердого раствора ZnCuO (0 ≤ х ≤ 0,1). Присутствие ее в оболочке композита ZnCuO / CuO негативно влияет на фотоактивность материала вплоть до подавления фотокатализа в видимом световом диапазоне. Показана также сорбционная эффективность материалов к мышьяку независимо от состава и морфологии материала. Согласно данным рентгеновской фотоэлектронной спектроскопии на поверхности образцов после сорбции мышьяк находится преимущественно в виде As(III) . 1D solid solutions ZnCuO and composites ZnCuO / CuO with spherical morphology of aggregates from formate glycolate complexes ZnCuO (HCOO)(OCHCHO) (0 ≤ x ≤ 0,15) were obtained. All materials have been tested in the reaction of As(III) photooxidation upon exposure to ultraviolet and visible radiation. It was found that copper is an effective doping impurity in the composition of the solid solution ZnCuO (0 ≤ x ≤ 0,1). Its presence in the shell of the ZnCuO / CuO composite negatively affects the photoactivity of the material up to suppression of photocatalysis in the visible light range. The sorption efficiency of materials for arsenic is also shown, regardless of the composition and morphology of the material. According to x-ray photoelectron spectroscopy data, the surface of the samples after sorption contains arsenic mainly in the form of As(III).

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Preparation of g-C3N4/MoS2 Composite Material and Its Visible Light Catalytic Performance

10.21203/rs.3.rs-627855/v1 ◽

2021 ◽

Author(s):

Yu Fan ◽

Yan-ning Yang ◽

Chen Ding

Keyword(s):

Electron Microscopy ◽

Photocatalytic Activity ◽

Visible Light ◽

Photoelectron Spectroscopy ◽

Photogenerated Electron ◽

Catalytic Performance ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Calcination Method

Abstract The g-C3N4 nanosheet was prepared by calcination method, the MoS2 nanosheet was prepared by hydrothermal method. The g-C3N4/MoS2 composites were prepared by ultrasonic composite in anhydrous ethanol. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectroscopy (UV-Vis), and photoluminescence (PL) techniques were used to characterize the materials. The photocatalytic degradation of Rhodamine B (Rh B) by g-C3N4/MoS2 composites with different mass ratios was investigated under visible light. The results show that a small amount of MoS2 combined with g-C3N4 can significantly improve photocatalytic activity. The g-C3N4/MoS2 composite with a mass ratio of 1:8 has the highest photocatalytic activity, and the degradation rate of Rh B increases from 50% to 99.6%. The main reason is that MoS2 and g-C3N4 have a matching band structure. The separation rate of photogenerated electron-hole pairs is enhanced. So the g-C3N4/MoS2 composite can improve the photocatalytic activity. The photocatalytic mechanism was proposed through the active matter capture experiment.

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In-Situ Synthesis of Nb2O5/g-C3N4 Heterostructures as Highly Efficient Photocatalysts for Molecular H2 Evolution under Solar Illumination

Catalysts ◽

10.3390/catal9020169 ◽

2019 ◽

Vol 9 (2) ◽

pp. 169 ◽

Cited By ~ 15

Author(s):

Faryal Idrees ◽

Ralf Dillert ◽

Detlef Bahnemann ◽

Faheem Butt ◽

Muhammad Tahir

Keyword(s):

Photocatalytic Activity ◽

Charge Carrier ◽

Surface Area ◽

High Surface ◽

High Surface Area ◽

Photogenerated Electron ◽

Band Alignment ◽

Solar Irradiation ◽

Electron Hole ◽

The Impact

This work focuses on the synthesis of heterostructures with compatible band positions and a favourable surface area for the efficient photocatalytic production of molecular hydrogen (H2). In particular, 3-dimensional Nb2O5/g-C3N4 heterostructures with suitable band positions and high surface area have been synthesized employing a hydrothermal method. The combination of a Nb2O5 with a low charge carrier recombination rate and a g-C3N4 exhibiting high visible light absorption resulted in remarkable photocatalytic activity under simulated solar irradiation in the presence of various hole scavengers (triethanolamine (TEOA) and methanol). The following aspects of the novel material have been studied systematically: the influence of different molar ratios of Nb2O5 to g-C3N4 on the heterostructure properties, the role of the employed hole scavengers, and the impact of the co-catalyst and the charge carrier densities affecting the band alignment. The separation/transfer efficiency of the photogenerated electron-hole pairs is found to increase significantly as compared to that of pure Nb2O5 and g-C3N4, respectively, with the highest molecular H2 production of 110 mmol/g·h being obtained for 10 wt % of g-C3N4 over Nb2O5 as compared with that of g-C3N4 (33.46 mmol/g·h) and Nb2O5 (41.20 mmol/g·h). This enhanced photocatalytic activity is attributed to a sufficient interfacial interaction thus favouring the fast photogeneration of electron-hole pairs at the Nb2O5/g-C3N4 interface through a direct Z-scheme.

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Efficient photocatalytic activity of bismuth oxyhalides with preferentially oriented (210) facets under visible light

10.1063/5.0002715 ◽

2020 ◽

Author(s):

Ratna Sarkar ◽

Dimitra Das ◽

Brahami Das ◽

Subrata Sarkar ◽

Kalyan K. Chattopadhyay

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Bismuth Oxyhalides

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Enhanced Photocatalytic CO2 Reduction over TiO2 Using Metalloporphyrin as the Cocatalyst

Catalysts ◽

10.3390/catal10060654 ◽

2020 ◽

Vol 10 (6) ◽

pp. 654

Author(s):

Ziyi Wang ◽

Wei Zhou ◽

Xin Wang ◽

Xueliang Zhang ◽

Huayu Chen ◽

...

Keyword(s):

Photocatalytic Activity ◽

High Efficiency ◽

Separation Efficiency ◽

Co2 Reduction ◽

Photogenerated Electron ◽

Green Technology ◽

Co2 Photoreduction ◽

Metal Centers ◽

Carbon Dioxide Co2 ◽

Photoinduced Charge

The photocatalytic reduction of carbon dioxide (CO2) into CO and hydrocarbon fuels has been considered as an ideal green technology for solar-to-chemical energy conversion. The separation/transport of photoinduced charge carriers and adsorption/activation of CO2 molecules play crucial roles in photocatalytic activity. Herein, tetrakis (4-carboxyphenyl) porphyrin (H2TCPP) was incorporated with different metal atoms in the center of a conjugate macrocycle, forming the metalloporphyrins TCPP-M (M = Co, Ni, Cu). The as-obtained metalloporphyrin was loaded as a cocatalyst on commercial titania (P25) to form TCPP-M@P25 (M = Co, Ni, Cu) for enhanced CO2 photoreduction. Among all of the TCPP-M@P25 (M = Co, Ni, Cu), TCPP-Cu@P25 exhibited the highest evolution rates of CO (13.6 μmol⋅g−1⋅h−1) and CH4 (1.0 μmol⋅g−1⋅h−1), which were 35.8 times and 97.0 times those of bare P25, respectively. The enhanced photocatalytic activity could be attributed to the improved photogenerated electron-hole separation efficiency, as well as the increased adsorption/activation sites provided by the metal centers in TCPP-M (M = Co, Ni, Cu). Our study indicates that metalloporphyrin could be used as a high-efficiency cocatalyst to enhance CO2 photoreduction activity.

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