scholarly journals Photoreduction of Carbon Dioxide to Methanol over Copper Based Zeolitic Imidazolate Framework-8: A New Generation Photocatalyst

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 581 ◽  
Author(s):  
Sonam Goyal ◽  
Maizatul Shaharun ◽  
Chong Kait ◽  
Bawadi Abdullah ◽  
Mariam Ameen
Keyword(s):  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Ammonium Hydroxide ◽  
Photocatalytic Reduction ◽  
Zeolitic Imidazolate Framework ◽  
X Ray ◽  
Efficient Reduction ◽  
Vis Spectroscopy ◽  
Metal Organic ◽  
Reduction Of Co2

The efficient reduction of CO2 into valuable products such as methanol, over metal-organic frameworks (MOFs) based catalyst, has received much attention. The photocatalytic reduction is considered the most economical method due to the utilization of solar energy. In this study, Copper (II)/Zeolitic Imidazolate Framework-8 (Cu/ZIF-8) catalysts were synthesized via a hydrothermal method for photocatalytic reduction of CO2 to methanol. The synthesized catalysts were characterized by X-ray Photoelectron Spectroscopy (XPS), Field Emission Scanning Electron Microscopy (FESEM) coupled with Energy Dispersive X-ray (EDX), Ultraviolet-visible (UV-vis) spectroscopy, and X-Ray Diffraction (XRD). The host ZIF-8, treated with 2 mmol copper prepared in 2M ammonium hydroxide solution showed the highest photocatalytic activity. The crystal structures of ZIF-8 and 2Cu/ZIF-8N2 catalysts were observed as cubic and orthorhombic, respectively and the XPS analysis confirmed the deposition of Cu (II) ions over ZIF-8 surface among all the prepared catalysts. The orthorhombic structure, nano-sized crystals, morphology and Cu loading of the 2Cu/ZIF-8N2 catalyst were the core factors to influence the photocatalytic activity. The yield of Methanol was found to be 35.82 µmol/L·g after 6 h of irradiations on 2Cu/ZIF-8N2 catalyst in the wavelength range between 530–580 nm. The copper-based ZIF-8 catalyst has proven as an alternative approach for the economical photocatalytic reduction of CO2 to CH3OH.

Synthesis, Characterization and Photocatalytic Activity of Nb-Doped TiO2 Nanoparticles

2012 ◽  
Vol 455-456 ◽  
pp. 110-114 ◽  
Author(s):  
Xuan Dong Li ◽  
Xi Jiang Han ◽  
Wen Ying Wang ◽  
Xiao Hong Liu ◽  
Yan Wang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Doped Tio2 ◽  
X Ray ◽  
Vis Spectroscopy

Nb-doped TiO2 powders with different concentrations of Nb have been synthesized by a sol-gel method and characterized by a series of technologies including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy. The photocatalytic activity of Nb-doped TiO2 is evaluated by degradation efficiency of methyl orange in aqueous solution. The results indicate that the photocatalytic activity of Nb-doped TiO2 synthesized with a Nb/Ti molar ratio of 5% is higher than that of TiO2 under the visible light.

Hydrothermal Fabrication of BiVO4/ Diatomite Composite Photocatalysts and their Photocatalytic Performance

2021 ◽  
Vol 904 ◽  
pp. 350-357
Author(s):  
Tian Qing Cui ◽  
Jun Feng Ma ◽  
Qun Si Wang ◽  
Qi Zhou ◽  
Dong Bin Tang
Keyword(s):  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Photocatalytic Performance ◽  
Hydrothermal Process ◽  
Precursor Solution ◽  
Chelating Agent ◽  
High Porosity ◽  
X Ray ◽  
Composite Photocatalysts ◽  
Vis Spectroscopy

A hydrothermal process was proposed to prepare BiVO4/ diatomite composite photocatalysts, where BiVO4 was grown from a precursor solution containing diatomite, and EDTA used as a chelating agent to prevent the precipitation of precursor solution compositions on diatomite before hydrothermal treatment. The effect of some processing parameters like diatomite percentage and Ag-loaded amount on their photocatalytic performance were also investigated in detail by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), BET, and UV‐Vis spectroscopy. The results show that BiVO4/ diatomite composite photocatalysts can be successfully prepared at 160 °C for the duration of 3h by the hydrothermal process. The diatomite has two significant impacts on their photocatalytic performance: (1) enhancing the dispersion of BiVO4 crystallites due to its high porosity and specific surface area to favor their photocatalytic performance, and (2) having a light screening effect to incident visible light to decrease their photocatalytic activity. Appropriately incorporating diatomite could improve their photocatalytic performance, but the overuse of diatomite would reduce that. Similarly, depositing Ag could effectively improve their photocatalytic activity because of its good light absorption and photosensitive characteristics, but excessive addition would result in their decrease since the overuse of Ag would also promote the electron-hole recombination.

Synthesis, Characterization and Photocatalytic Activity of Copper (II)-Doped Titanium Dioxide Powders

2011 ◽  
Vol 391-392 ◽  
pp. 728-731 ◽  
Author(s):  
Wen Churng Lin ◽  
Wein Duo Yang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Specific Surface ◽  
Photoelectron Spectroscopy ◽  
Effective Means ◽  
Sol Gel ◽  
Particle Growth ◽  
X Ray ◽  
Surface Areas ◽  
Vis Spectroscopy

Different concentration of copper (II) doped TiO2 photocatalyst powders were synthesized through the sol-gel method and characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET)-specific surface area, transmission electron microscopy (TEM), and Ultraviolet–Visible (UV-Vis) spectroscopy. Cu2+-doping in the TiO2 promotes the particle growth, decreases the specific surface areas of powders, extends the absorption to visible light regions, and exhibits the vis-photocatalytic activity for methylene blue (MB) degradation. Appropriate content of Cu2+-doping is an effective means to improve the photocatalytic activity of TiO2 for MB degradation under visible light irradiation.

scholarly journals Synthesis, Characterization and Photocatalytic Performance of Calcined ZnCr-Layered Double Hydroxides

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3051
Author(s):  
Somia Djelloul Bencherif ◽  
Juan Jesús Gallardo ◽  
Iván Carrillo-Berdugo ◽  
Abdellah Bahmani ◽  
Javier Navas
Keyword(s):  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Textural Properties ◽  
Operational Parameters ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Crystal Violet Dye ◽  
Double Hydroxide ◽  
Double Hydroxides

The development of new materials for performing photocatalytic processes to remove contaminants is an interesting and important research line due to the ever-increasing number of contaminants on our planet. In this sense, we developed a layered double hydroxide material based on Zn and Cr, which was transformed into the corresponding oxide by heat treatment at 500 °C. Both materials were widely characterized for their elemental composition, and structural, morphological, optical and textural properties using several experimental techniques such as x-ray diffraction, x-ray photoelectron spectroscopy, scanning and transmission electron microscopy, Fourier transform infrared spectroscopy, UV-vis spectroscopy and physisorption techniques. In addition, the photocatalytic activity of both materials was analysed. The calcined one showed interesting photocatalytic activity in photodegradation tests using crystal violet dye. The operational parameters for the photocatalytic process using the calcined material were optimised, considering the pH, the initial concentration of the dye, the catalyst load, and the regeneration of the catalyst. The catalyst showed good photocatalytic activity, reaching a degradation of 100% in the optimised conditions and showing good performance after five photodegradation cycles.

Metal–organic frameworks (ZIF-67) as efficient cocatalysts for photocatalytic reduction of CO2: the role of the morphology effect

2018 ◽  
Vol 6 (11) ◽  
pp. 4768-4775 ◽  
Author(s):  
Mang Wang ◽  
Jinxuan Liu ◽  
Chunmei Guo ◽  
Xiaosu Gao ◽  
Chenghuan Gong ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Photocatalytic Activity ◽  
Metal Organic Frameworks ◽  
Photocatalytic Reduction ◽  
Two Dimensional ◽  
Metal Organic ◽  
Morphology Effect ◽  
Reduction Of Co2 ◽  
Adsorption Capability

The two-dimensional ZIF-67 with a leaf-like morphology exhibited the best photocatalytic activity and stability due to the highest CO2 adsorption capability and efficient electron transfer from the excited [Ru(bpy)3]2+ to ZIF-67.

scholarly journals A Novel Bi2MoO6/ZIF-8 Composite for Enhanced Visible Light Photocatalytic Activity

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 545 ◽  
Author(s):  
Yu Xia ◽  
Shao-ke Shang ◽  
Xie-rong Zeng ◽  
Ji Zhou ◽  
Ya-yun Li
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Photocatalytic Performance ◽  
Molar Ratio ◽  
Zeolitic Imidazolate Framework ◽  
X Ray ◽  
Suitable Amount ◽  
Electron Hole Pair

A series of novel Bi2MoO6/zeolitic imidazolate framework-8 (ZIF-8) photocatalysts have been successfully fabricated through a facile self-assembly process. X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis spectrophotometry, and X-ray photoelectron spectroscopy (XPS) characterized pure Bi2MoO6, pure ZIF-8, and a series of Bi2MoO6/ZIF-8 composites. The result indicated that, when compared with pure Bi2MoO6, the composite of Bi2MoO6/ZIF-8 exhibited excellent photocatalytic performance for the degradation of methylene blue (MB) under visible light. Moreover, the Bi2MoO6/ZIF-8-3 composite (the molar ratio of Bi2MoO6 to 2-MI is 3:3) has optimum photocatalytic performance because of the suitable amount of ZIF-8 decorated on the flower-like Bi2MoO6. The enhanced photocatalytic activity is probably due to the introduction of ZIF-8, which will promote the separation of electron–hole pair and the surface morphology. Benefitting from the diversity of the MOF species (ZIF-8 is one of them), this composing strategy of Bi2MoO6/MOF composite would provide new insight into the design of highly efficient visible light photocatalysts.

Preparation and Photocatalytic Activity of N-TiO2/Sepiolite Nanocomposite

2011 ◽  
Vol 694 ◽  
pp. 85-90
Author(s):  
Dai Mei Chen ◽  
Hai Peng Ji ◽  
Jian Xin Wang ◽  
Jian Chen ◽  
Zheng Ming Wu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Methylene Blue Degradation ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Photocatalytic Reactions ◽  
Nitrogen Contents

To utilize visible light and separate of TiO2 nanoparticles more efficiently in photocatalytic reactions, nitrogen doped TiO2/sepiolite composites (N-TiO2/sep) with different nitrogen contents were prepared by a sol-gel method and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy. XRD showed that anatase-TiO2 nanoparticles were loaded on the surface of sepiolite. XPS revealed that N atoms could incorporate into the lattice of anatase TiO2 substituting the sites of oxygen atoms. UV-vis spectroscopy showed that the visible light absorption of N-TiO2/sep samples decreased with the increase of calciantion temperature and increased with the increase of N content. The photocatalytic activities of obtained N-TiO2/sep samples were evaluated by methylene blue degradation under visible light irradiation. It was found that the N-TiO2/sep samples had the higher photocatalytic activity than that of TiO2/sep.

scholarly journals Tm-doped TiO2 and Tm2Ti2O7 pyrochlore nanoparticles: enhancing the photocatalytic activity of rutile with a pyrochlore phase

2015 ◽  
Vol 6 ◽  
pp. 605-616 ◽  
Author(s):  
Desiré M De los Santos ◽  
Javier Navas ◽  
Teresa Aguilar ◽  
Antonio Sánchez-Coronilla ◽  
Concha Fernández-Lorenzo ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Anatase Phase ◽  
Pyrochlore Phase ◽  
Rutile Phase ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Controlled Hydrolysis

Tm-doped TiO2 nanoparticles were synthesized using a water-controlled hydrolysis reaction. Analysis was performed in order to determine the influence of the dopant concentration and annealing temperature on the phase, crystallinity, and electronic and optical properties of the resulting material. Various characterization techniques were utilized such as X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and UV–vis spectroscopy. For the samples annealed at 773 and 973 K, anatase phase TiO2 was obtained, predominantly internally doped with Tm3+. ICP–AES showed that a doping concentration of up to 5.8 atom % was obtained without reducing the crystallinity of the samples. The presence of Tm3+ was confirmed by X-ray photoelectron spectroscopy and UV–vis spectroscopy: the incorporation of Tm3+ was confirmed by the generation of new absorption bands that could be assigned to Tm3+ transitions. Furthermore, when the samples were annealed at 1173 K, a pyrochlore phase (Tm2Ti2O7) mixed with TiO2 was obtained with a predominant rutile phase. The photodegradation of methylene blue showed that this pyrochlore phase enhanced the photocatalytic activity of the rutile phase.

scholarly journals Investigating Visible-Photocatalytic Activity of MoS2/TiO2 Heterostructure Thin Films at Various MoS2 Deposition Times

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Hang Nguyen Thai Phung ◽  
Van Nguyen Khanh Tran ◽  
Lam Thanh Nguyen ◽  
Loan Kieu Thi Phan ◽  
Phuong Ai Duong ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Photoelectron Spectroscopy ◽  
Light Irradiation ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Visible Photocatalytic Activity

MoS2/TiO2 heterostructure thin films were fabricated by sol-gel and chemical bath deposition methods. Crystal structure, surface morphology, chemical states of all elements, and optical property of the obtained thin films were characterized by using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and UV-Vis spectroscopy techniques, respectively. Photocatalytic activity of all thin films was evaluated by measuring decomposition rate of methylene blue solution under visible light irradiation. The results indicate that ultrathin MoS2 film on TiO2-glass substrate improves photocatalytic activity of TiO2 in the visible light due to the efficient absorption of visible photon of MoS2 few layers and the transfer of electrons from MoS2 to TiO2. All MoS2/TiO2 heterostructure thin films exhibit higher visible light photocatalytic activity than that of pure MoS2 and TiO2 counterparts. The best MoS2/TiO2 heterostructure thin film at MoS2 layer deposition time of 45 minutes can decompose about 60% MB solution after 150 minutes under visible light irradiation. The mechanism of the enhancement for visible-photocatalytic activity of MoS2/TiO2 heterostructure thin film was also discussed.

scholarly journals Photocatalytic reduction of graphene oxide with cuprous oxide film under UV-vis irradiation

2020 ◽  
Vol 59 (1) ◽  
pp. 207-214 ◽  
Author(s):  
Yao Wang ◽  
Jianqing Feng ◽  
Lihua Jin ◽  
Chengshan Li
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Low Cost ◽  
Photocatalytic Reduction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Reduced Graphene ◽  
Reduction Efficiency ◽  
Metal Organic ◽  
Reduction Effect

AbstractWe have grown Cu2O films by different routes including self-oxidation and metal-organic deposition (MOD). The reduction efficiency of Cu2O films on graphene oxide (GO) synthesized by modified Hummer’s method has been studied. Surface morphology and chemical state of as-prepared Cu2O film and GO sheets reduced at different conditions have also been investigated using atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS). Results show that self-oxidation Cu2O film is more effective on phtocatalytic reduction of GO than MOD-Cu2O film. Moreover, reduction effect of self-oxidation Cu2O film to GO is comparable to that of environmental-friendly reducing agent of vitamin C. The present results offer a potentially eco-friendly and low-cost approach for the manufacture of reduced graphene oxide (RGO) by photocatalytic reduction.

Sign in / Sign up

Export Citation Format

Share Document