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https://www.readbyqxmd.com/read/28549328/enhanced-photocatalytic-hydrogen-production-from-aqueous-sulfide-sulfite-solution-by-zno0-6s0-4-with-simultaneous-dye-degradation-under-visible-light-irradiation
#1
Ka Him Chu, Liqun Ye, Wei Wang, Dan Wu, Donald Ka Long Chan, Cuiping Zeng, Ho Yin Yip, Jimmy C Yu, Po Keung Wong
Photocatalytic hydrogen (H2) production was performed by visible-light-driven (VLD) ternary photocatalyst, zinc oxysulfide (ZnO0.6S0.4) in the presence of sulfide/sulfite (S2(2-)/SO3(2-)) sacrificing system, with simultaneous azo-dye Reactive Violet 5 (RV5) degradation. Enhancement in both RV5 degradation and H2 production was achieved, with the promotion of H2 production after decolorization of RV5. The effect of initial concentration of RV5 was found to be influential on the enhancement of H2 during the simultaneous processes, with a maximum of 110% increase of H2 produced...
May 20, 2017: Chemosphere
https://www.readbyqxmd.com/read/28548158/visible-light-assisted-hydrogen-generation-from-complete-decomposition-of-hydrous-hydrazine-using-rhodium-modified-tio2-photocatalysts
#2
Pawan Kumar, Anurag Kumar, Clémence Queffélec, Dietrich Gudat, Qi Wang, Suman L Jain, Rabah Boukherroub, Sabine Szunerits
Hydrogen is considered to be an ideal energy carrier, which produces only water when combined with oxygen and thus has no detrimental effect on the environment. While the catalytic decomposition of hydrous hydrazine for the production of hydrogen is well explored, little is known about its photocatalytic decomposition. The present paper describes a highly efficient photochemical methodology for the production of hydrogen through the decomposition of aqueous hydrazine using titanium dioxide nanoparticles modified with a Rh(i) coordinated catechol phosphane ligand (TiO2-Rh) as a photocatalyst under visible light irradiation...
May 26, 2017: Photochemical & Photobiological Sciences
https://www.readbyqxmd.com/read/28546886/high-photocatalytic-activity-of-fe2o3-tio2-nanocomposites-prepared-by-photodeposition-for-degradation-of-2-4-dichlorophenoxyacetic-acid
#3
Shu Chin Lee, Hendrik O Lintang, Leny Yuliati
Two series of Fe2O3/TiO2 samples were prepared via impregnation and photodeposition methods. The effect of preparation method on the properties and performance of Fe2O3/TiO2 for photocatalytic degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) under UV light irradiation was examined. The Fe2O3/TiO2 nanocomposites prepared by impregnation showed lower activity than the unmodified TiO2, mainly due to lower specific surface area caused by heat treatment. On the other hand, the Fe2O3/TiO2 nanocomposites prepared by photodeposition showed higher photocatalytic activity than the unmodified TiO2...
2017: Beilstein Journal of Nanotechnology
https://www.readbyqxmd.com/read/28544453/black-tungsten-nitride-as-metallic-photocatalyst-for-overall-water-splitting-operable-at-up-to-765-nm
#4
Yu Lei Wang, Ting Nie, Yu Hang Li, Xue Lu Wang, Li Rong Zheng, Ai Ping Chen, Xue Qing Gong, Huagui Yang
Semiconductor photocatalysts are hardly to be employed for overall water splitting beyond 700 nm, owing to both thermodynamic aspects and activation barriers. Metallic materials as photocatalysts are known to overcome this limitation through interband transitions for creating electron-hole pairs, however, the application of metallic photocatalysts for overall water splitting has never been fulfilled. Here we report, for the first time, that the black tungsten nitride can be employed as metallic photocatalyst for overall water splitting at wavelengths of up to 765 nm...
May 19, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28544022/covalently-modified-graphenes-in-catalysis-electrocatalysis-and-photoresponsive-materials
#5
Sergio Navalon, Jose Raul Herance, Mercedes Alvaro, Hermenegildo García
Ideal graphene is a one-atom thick single layer of carbon atoms having sp2 hybridation in hexagonal arrangement. Due to their large surface area and good dispersability in common solvents, graphenes are suitable platforms to anchor covalently units. The appended unit can introduce additional functionality to graphene. Although the field of covalently modified graphene is still starting compared to the development of other carbon nanoforms, there is alrady many examples describing the use of modified graphenes as recoverable photo-, electro- and catalysts as well as in non-linear optics and to improve mechanical resistance and solubility of graphenes...
May 25, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28541049/synthesis-and-photophysical-and-photocatalytic-properties-of-a-highly-fluorinated-and-durable-phthalocyanine-peptide-bioconjugate-for-potential-theranostic-applications
#6
Erik N Carrión, Jenyffer Santiago, David Sabatino, Sergiu M Gorun
The functionalized, asymmetric fluoro-fluoroalkyl scaffold F48H7COOHPcZn (3) was used to prepare F48H7COOPcZn-6-amino-hexanoate-CTVALPGGYVRVC (5), a Pep42 peptide bioconjugate envisioned for photodynamic therapy, which can specifically target the GRP78 chaperone protein overexpressed and exclusively localized on some cancer cell surfaces. The analogous F48H7COOHPcCu (4) has also been prepared, and its single-crystal X-ray structure was elucidated. Despite reduced steric hindrance relative to the nonfunctionalized, single-site complexes of the F64Pc scaffold, no aggregation was detected in solution via UV-vis spectroscopy, for either 3, 4, or 5, consistent with the lack of π stacking observed for the crystalline 4...
May 25, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28540718/oriented-built-in-electric-field-introduced-by-surface-gradient-diffusion-doping-for-enhanced-photocatalytic-h2-evolution-in-cds-nanorods
#7
Hengming Huang, Baoying Dai, Wei Wang, Chunhua Lu, Jiahui Kou, Yaru Ni, Lianzhou Wang, Zhongzi Xu
Element doping has been extensively attempted to develop visible-light-driven photocatalysts, which introduces impurity levels and enhances light absorption. However, the dopants can also become recombination centers for photogenerated electrons and holes. To address the recombination challenge, we report a gradient phosphorus-doped CdS (CdS-P) homojunction nanostructure, creating an oriented built-in electric-field for efficient extraction of carriers from inside to surface of the photocatalyst. The apparent quantum efficiency (AQY) based on the cocatalyst-free photocatalyst is up to 8...
May 25, 2017: Nano Letters
https://www.readbyqxmd.com/read/28539988/adsorption-study-of-a-water-molecule-on-vacancy-defected-nonpolar-cds-surfaces
#8
S S Gupta, M A van Huis
A detailed understanding of the water-semiconductor interface is of major importance for elucidating the molecular interactions at the photocatalyst's surface. Here, we studied the effect of vacancy defects on the adsorption of a water molecule on the (101̅0) and (112̅0) CdS surfaces, using spin-polarized density functional theory. We observed that the local spin polarization did not persist for most of the cationic vacancies on the surfaces, unlike in bulk, owing to surface reconstructions caused by displaced S atoms...
May 11, 2017: Journal of Physical Chemistry. C, Nanomaterials and Interfaces
https://www.readbyqxmd.com/read/28537609/nanoparticle-induced-oxidation-of-corona-proteins-initiates-an-oxidative-stress-response-in-cells
#9
Dhanya T Jayaram, Sabiha Runa, Melissa L Kemp, Christine K Payne
Titanium dioxide nanoparticles (TiO2 NPs), used as pigments and photocatalysts, are ubiquitous in our daily lives. Previous work has observed cellular oxidative stress in response to the UV-excitation of photocatalytic TiO2 NPs. In comparison, most human exposure to TiO2 NPs takes place in the dark, in the lung following inhalation or in the gut following consumption of TiO2 NP food pigment. Our spectroscopic characterization shows that both photocatalytic and food grade TiO2 NPs, in the dark, generate low levels of reactive oxygen species (ROS), specifically hydroxyl radicals and superoxides...
May 24, 2017: Nanoscale
https://www.readbyqxmd.com/read/28535670/ultrafast-spectroscopy-reveals-electron-transfer-cascade-that-improves-hydrogen-evolution-with-carbon-nitride-photocatalysts
#10
Kathryn L Corp, Cody W Schlenker
Solar hydrogen generation from water represents a compelling component of a future sustainable energy portfolio. Recently, chemically-robust heptazine-based polymers known as graphitic carbon nitrides (g-C3N4) have emerged as promising photocatalysts for hydrogen evolution using visible light while withstanding harsh chemical environments. However, since g-C3N4 electron transfer dynamics are poorly understood, rational design rules for improving activity remain unclear. Here, we use visible and near-infrared femtosecond transient absorption (TA) spectroscopy to reveal an electron transfer cascade that correlates with a near-doubling in photocatalytic activity from 2050 µmol h(-1)g(-1) to 3810 µmol h(-1)g(-1) when we infuse a suspension of bulk g-C3N4 with 10% mass loading of chemically exfoliated carbon nitride...
May 23, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28534917/charge-stabilizing-tris-triphenylamine-zinc-porphyrin-carbon-nanotube-hybrids-synthesis-characterization-and-excited-state-charge-transfer-studies
#11
Luis M Arellano, Myriam Barrejón, Habtom B Gobeze, María J Gómez-Escalonilla, José Luis G Fierro, Francis D'Souza, Fernando Langa
Functionalization of single-walled (SWCNTs) and double-walled carbon nanotubes (DWCNTs) with a charge stabilizing zinc porphyrin functionalized with triphenylamine entities has been accomplished. The synthetic approach involved the reaction of tris-(triphenylamine)porphyrinato zinc(ii) with iodobenzene functionalized nanotubes through a Sonogashira C-C cross coupling reaction under microwave irradiation conditions. Evidence of covalent functionalization and the extent of functionalization was obtained from systematic studies carried out by AFM, TGA, XPS and Raman spectroscopy techniques...
May 23, 2017: Nanoscale
https://www.readbyqxmd.com/read/28534585/development-of-ir-and-la-codoped-bata2o6-photocatalysts-using-visible-light-up-to-640-nm-as-an-h2-evolving-photocatalyst-for-z-schematic-water-splitting
#12
Akihide Iwase, Akihiko Kudo
Ir and La-codoped BaTa2O6 was developed as a novel photocatalyst for H2 evolution utilizing visible light up to 640 nm. The Ir and La-codoped BaTa2O6 with a Ru cocatalyst functioned as an H2-evolving photocatalyst for Z-schematic water splitting under visible light irradiation upon combination with a BiVO4 O2-evolving photocatalyst and a [Co(bpy)3](3+/2+) electron mediator.
May 23, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28533554/facile-synthesis-and-characterization-of-zno-nanoparticles-grown-on-halloysite-nanotubes-for-enhanced-photocatalytic-properties
#13
Hongxia Peng, Xiaohe Liu, Wei Tang, Renzhi Ma
We demonstrated herein that ZnO nanoparticle with sizes in the range of 3-5 nm grown on the surface of halloysite nanotubes (HNTs) could be facile prepared in large quantities through the seed-mediated growth process using ZnAc2·2H2O as the zinc source. Compared with the individually dispersed ZnO nanoparticles, the as-prepared HNTs@ZnO nanocomposites showed a smaller band gap energy and relatively strong light absorption. Therefore, HNTs@ZnO nanocomposites possessed higher photocatalytic activity than individually dispersed ZnO nanoparticles, exhibiting the HNTs@ZnO nanocomposites could be used as highly efficient photocatalysts...
May 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28531961/challenges-in-photocatalytic-reduction-of-nitrate-as-a-water-treatment-technology
#14
Heather O'Neal Tugaoen, Sergi Garcia-Segura, Kiril Hristovski, Paul Westerhoff
Management of ubiquitous nitrate contamination in drinking water sources is a major engineering challenge due to its negative impacts from eutrophication to immediate risk to human health. Several water treatment technologies exist to manage nitrate pollution in water sources. However, the most widely used technologies are phase separation treatments. In this context, nanoscale photocatalysis emerges as a highly promising transformative technology capable of reducing nitrate to innocuous nitrogen with noticeable selectivity...
May 17, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28531657/efficient-water-disinfection-with-ag2wo4-doped-mesoporous-g-c3n4-under-visible-light
#15
Yi Li, Yanan Li, Shuanglong Ma, Pengfei Wang, Qianlei Hou, Jingjing Han, Sihui Zhan
Ag2WO4/g-C3N4 composite photocatalyst was synthesized by polymerization of thiourea and ammonia chloride combined with the deposition-precipitation method, which was applied as an efficient visible-light driven photocatalyst for inactivating Escherichia coli (E. coli). The physicochemical properties of these photocatalysts were systematically characterized by various techniques such as SEM, TEM, XRD, FT-IR, BET, UV-vis DRS and PL. The synthesized photocatalysts exhibited outstandingly enhanced photocatalytic disinfection efficiency compared with that of pure g-C3N4 and Ag2WO4 under visible light...
May 11, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28531162/ctab-assisted-fabrication-of-bi%C3%A2-wo%C3%A2-thin-nanoplates-with-high-adsorption-and-enhanced-visible-light-driven-photocatalytic-performance
#16
Yuxue Zhou, Pengfei Lv, Xiangdong Meng, Yanping Tang, Pingping Huang, Xiaobing Chen, Xiaoshuang Shen, Xianghua Zeng
Two-dimensional thin Bi₂WO₆ nanoplates have been fabricated using a cetyltrimethylammonium bromide (CTAB)-assisted hydrothermal method. We investigated the proposed formation mechanism based on the crystalline structures of the thin Bi₂WO₆ nanoplates. The high adsorption ability and excellent visible-light driven photocatalytic activities of the Bi₂WO₆ nanoplates were illustrated, in view of exposed (001) facets of nanoplates possessing faster separation of photo-generated charge carriers and increased catalytically active sites...
May 22, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28530763/surface-oxygen-vacancy-induced-solar-light-activity-enhancement-of-a-cdwo4-bi2o2co3-core-shell-heterostructure-photocatalyst
#17
Chunming Yang, Guimei Gao, Junjun Zhang, Ruiping Liu, Ruicheng Fan, Ming Zhao, Yongwang Wang, Shucai Gan
A CdWO4/Bi2O2CO3 core-shell heterostructure photocatalyst was fabricated via a facile two-step hydrothermal process. Flower-like Bi2O2CO3 was synthesized and functioned as the cores on which CdWO4 nanorods were coated as the shells. Photoluminescence (PL) spectra and electron paramagnetic resonance (EPR) demonstrate that the CdWO4/Bi2O2CO3 core-shell heterostructure photocatalyst possesses a large amount of oxygen vacancies, which induce defect levels in the band gap and help to broaden light absorption. The photocatalyst exhibits enhanced photocatalytic activity for Rhodamine B (RhB), methylene blue (MB), methyl orange (MO), and colorless contaminant phenol degradation under solar light irradiation...
May 22, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28530722/the-origin-of-enhanced-photocatalytic-activities-of-hydrogenated-tio2-nanoparticles
#18
Yani Liu, Haifeng Feng, Xiaobing Yan, Jiaou Wang, Huagui Yang, Yi Du, Weichang Hao
The photocatalytic activity of semiconductors is largely governed by their light absorption, separation of photoinduced charge carriers and surface catalytically active sites, which are primarily controlled by the morphology, crystalline size, structure, and especially the electronic structure of photocatalysts. Black TiO2 is recognized as one of the most promising visible-light photocatalysts, due to its significantly enhanced visible-light photocatalytic performance in comparison to intrinsic TiO2. In this work, black TiO2 is synthesized through the hydrogenation process...
May 22, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28530182/green-synthesis-of-highly-stable-carbon-nanodots-and-their-photocatalytic-performance
#19
Rashmi Mahajan, Akhshay Singh Bhadwal, Nishant Kumar, Mukil Madhusudanan, Ramesh Namdeo Pudake, Ravi Mani Tripathi
The present study reports a novel, facile, biosynthesis route for the synthesis of carbon nanodots (CDs) with an approximate quantum yield of 38.5%, using Musk melon extract as a naturally derived-precursor material. The synthesis of CDs was established by using ultraviolet-visible (UV-vis) spectroscopy, Dynamic light scattering, photoluminescence spectroscopy, X-ray diffraction, transmission electron microscopy and Fourier transform infrared (FTIR) spectroscopy. The as-prepared CDs possess an eminent fluorescence under UV-light (λex = 365 nm)...
June 2017: IET Nanobiotechnology
https://www.readbyqxmd.com/read/28529675/role-of-dissociatively-adsorbed-water-on-the-formation-of-shallow-trapped-electrons-in-tio2-photocatalysts
#20
Anton Litke, Emiel J M Hensen, Jan P Hofmann
The mismatch between short lifetimes of free charge carriers and slow kinetics of surface redox reactions substantially limits the efficiency of most photocatalytic systems. Hence, the knowledge of trapping and recombination of photogenerated electrons and holes at different time scales is key for a rational optimization of photocatalytic materials. In this study, we used subsecond time-resolved diffuse-reflectance FTIR spectroscopy to investigate how energy and intensity of the incident irradiation affect the dynamics of photogenerated charge carriers in TiO2 P25 photocatalysts subjected to different pretreatments and how shallow trapped electrons (STE) are formed under these conditions...
May 11, 2017: Journal of Physical Chemistry. C, Nanomaterials and Interfaces
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