Production of pyridinecarboxy aldehydes, nicotinic and isonicotinic and picolinic acids by TiO2-sacrificial photocatalysis at ambient conditions and in aqueous solution through artificial solar radiation

2015 ◽  
Vol 163 ◽  
pp. 248-257 ◽  
Author(s):  
Danilo Spasiano ◽  
Raffaele Marotta ◽  
Ilaria Di Somma ◽  
Giuseppe Mancini
Keyword(s):  
Aqueous Solution ◽  
Solar Radiation ◽  
Ambient Conditions ◽  
Picolinic Acids ◽  
Sacrificial Photocatalysis

Study of aerobic oxidation of phenyl PtII complexes (dpms)PtIIPh(L) (dpms = di(2-pyridyl)methanesulfonate; L = water, methanol, or aniline)

2009 ◽  
Vol 87 (1) ◽  
pp. 110-120 ◽  
Author(s):  
Julia R Khusnutdinova ◽  
Peter Y Zavalij ◽  
Andrei N Vedernikov
Keyword(s):  
Aqueous Solution ◽  
Aerobic Oxidation ◽  
Reductive Elimination ◽  
High Yield ◽  
Ambient Conditions ◽  
Activation Barriers ◽  
Methanol Solutions ◽  
Anionic Species ◽  
Mechanism Of Oxidation ◽  
Solution Mechanism

Oxidation of phenyl PtII complexes K[(dpms)PtIIPh2], 1, (dpms)PtIIPh(MeOH), 2, (dpms)PtIIPh(OH2), 3, and methyl PtII complex (dpms)PtIIMe(NH2Ph), 6, with O2 in aqueous or methanol solutions under ambient conditions leads to corresponding (dpms)PtIVR(X)OH complexes (R = X = Ph, 7; R = Ph, X = OH, 8; R = Ph, X = OMe, 9; R = Me, X = NHPh; 11; dpms = di(2-pyridyl)methanesulfonate). Complexes 7–9 could be isolated in high yield. Complex 11 as well as its phenyl analogue (dpms)PtIVPh(NHPh)OH, 10 can be prepared in high yield by oxidation of corresponding (dpms)PtIIR(NH2Ph) with H2O2 in methanol. Phenyl PtII complexes (dpms)PtIIPh(HX) derived from HX = aniline and DMSO, 4 and 5, respectively, are inert toward O2. The rate of oxidation of 1–5 with O2 decreases in the order 1 > 3 ~ 2 » 4, and 5 is unreactive. Methyl analogues are significantly more reactive compared with their phenyl counterparts. Proposed mechanism of oxidation with O2 includes formation of anionic species (dpms)PtIIR(X)– responsible for reaction with dioxygen. Attempts at C–O and C–N reductive elimination from phenyl PtIV complexes 7–10 do not lead to phenyl derivatives PhX at 80–100 °C, consistent with the results of the DFT estimates of corresponding activation barriers, ΔG0 exceeding 28 kcal/mol.Key words: platinum phenyl complexes, oxidation, dioxygen, aqueous solution, mechanism.

Preparation of CuO Nanopowder in Aqueous Solution by Applying Ultrasonic and its CO Gas Sensitivity

2007 ◽  
Vol 544-545 ◽  
pp. 901-904 ◽  
Author(s):  
Ji Bum Yang ◽  
Tae Gyung Ko ◽  
Sang Jin Jung ◽  
Jae Hee Oh
Keyword(s):  
Aqueous Solution ◽  
Gas Sensing ◽  
Spherical Shape ◽  
Particle Morphology ◽  
High Yield ◽  
Ambient Conditions ◽  
Gas Sensitivity ◽  
Molar Ratios ◽  
Naoh Solution ◽  
Co Gas

We report on a process in which CuO nanopowder was produced in a high yield by adopting ultrasonic in aqueous solution. In our experiment, CuCl2 solution was reacted with NaOH solution and NaNO2, at ambient conditions applying ultrasonic for 5 min. Precipitation was performed by varying the molar ratios of NaOH/CuCl2 and NaNO2/CuCl2. CuO nanoparticles of ~ 5 nm and spherical shape were obtained at the NaOH/CuCl2 of 2.0 and the NaNO2/CuCl2 of 0.097. Without ultrasonication, an amorphous phase was formed at these conditions. This indicates that sonochemical reaction facilitates direct formation of the nanosized CuO particles. In addition, the particle morphology varied from sphere through ellipsoid to needle forms depending on pH. In thick films prepared with the CuO powder for gas sensing, the maximum CO gas sensitivity reached 93 % at the temperature of 250 °C and depended linearly on CO concentration in log scale over the range of 10 ~ 104 ppm.

Rational Design of Fe–N/C Hybrid for Enhanced Nitrogen Reduction Electrocatalysis under Ambient Conditions in Aqueous Solution

ACS Catalysis ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 336-344 ◽  
Author(s):  
Ying Wang ◽  
Xiaoqiang Cui ◽  
Jingxiang Zhao ◽  
Guangri Jia ◽  
Lin Gu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Rational Design ◽  
Ambient Conditions ◽  
Nitrogen Reduction

Ultrasonic Formation of Copper/Iron Graphene Oxide for Ketorolac Delivery

2019 ◽  
Vol 18 (03n04) ◽  
pp. 1940072
Author(s):  
D. Radziuk ◽  
L. Mikhnavets ◽  
L. Tabulina ◽  
V. Labunov ◽  
M. Vorokhta ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Graphene Oxide ◽  
Decay Constant ◽  
Decay Curve ◽  
Ambient Conditions ◽  
Iron Compounds ◽  
Ph Values ◽  
Curve Fit ◽  
Modified Graphene Oxide ◽  
Modified Graphene

New accessible sonochemical methods were developed for the functionalization of synthesized graphene oxide (GO) with copper/iron compounds and drug intercalation into their structure in aqueous solution at ambient conditions by using ultrasound (20[Formula: see text]kHz) treatment. The sonochemical formation mechanism of a new nanomaterial was revealed through the structural analysis of three types of nanocomposites: (i) copper@graphene oxide, (ii) copper/iron@graphene oxide and (iii) iron@graphene oxide. Unique copper/iron-modified graphene oxide nanocomposites can be used as nanocarriers for the anti-inflammatory drug (ketorolac) delivery in aqueous solution due to the reduced submicron size and enlarged surface area. Disintegration of the ultrasonically intercalated ketorolac followed the exponential decay curve fit at higher pH values of the aqueous solution with a higher decay constant observed in copper/iron-modified graphene oxide nanocomposites.

Electrochemical nitrogen reduction to ammonia at ambient conditions on nitrogen and phosphorus co-doped porous carbon

2019 ◽  
Vol 55 (5) ◽  
pp. 687-690 ◽  
Author(s):  
Pengfei Song ◽  
Hao Wang ◽  
Li Kang ◽  
Baocheng Ran ◽  
Honghong Song ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Porous Carbon ◽  
Ambient Conditions ◽  
Nitrogen And Phosphorus ◽  
Nitrogen Reduction ◽  
Highly Efficient ◽  
Co Doped

N,P co-doped porous carbon as a highly efficient electrocatalyst for N2 fixation in aqueous solution under ambient conditions.

Solar radiation exposure of dihydrobiopterin and biopterin in aqueous solution

Solar Energy ◽  
2014 ◽  
Vol 109 ◽  
pp. 45-53 ◽  
Author(s):  
Adriana Ipiña ◽  
Carolina Castaño ◽  
M. Laura Dántola ◽  
Andrés H. Thomas
Keyword(s):  
Aqueous Solution ◽  
Solar Radiation ◽  
Radiation Exposure ◽  
Solar Radiation Exposure

High-Magnesium Calcite Mesocrystals: Formation in Aqueous Solution under Ambient Conditions

2017 ◽  
Vol 56 (51) ◽  
pp. 16202-16206 ◽  
Author(s):  
Pao-Tao Yu ◽  
Chieh Tsao ◽  
Chun-Chieh Wang ◽  
Chun-Yu Chang ◽  
Chia-Hsin Wang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Ambient Conditions ◽  
Magnesium Calcite ◽  
High Magnesium Calcite

Preparation of Visible Light Response K6SiW11O39SnII for Photocatalytic Degradation of Acid Brilliant Scarlet

2012 ◽  
Vol 476-478 ◽  
pp. 2005-2008
Author(s):  
Xiu Hua Zhu ◽  
Jia Huan Liu ◽  
Li Li Zhao ◽  
Peng Yuan Wang
Keyword(s):  
Aqueous Solution ◽  
Solar Radiation ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Light Response ◽  
Photocatalytic Decomposition ◽  
Initial Concentration ◽  
Environmental Friendly ◽  
Visible Light Response ◽  
Initial Ph

Environmental friendly materials, K6SiW11O39SnⅡ(abbreviated as SiWSn), was synthesized, which is visible light response photocatalyst. The photocatalytic decomposition of Acid Brilliant Scarlet (abbreviated as ABS) aqueous solution with SiWSn was investigated using a broad spectrum of solar radiation. The results showed that the photocatalytic degradation efficiency of ABS with SiWSn was affected by the initial pH of ABS solution, the amount of SiWSn and the photolysis time. When the initial pH of ABS solution was 5, the initial concentration of that (20mL) was 3mg L-1, the concentration of SiWSn was 1.25g L-1, and it was irradiated 4h under the sunlight, the discoloration rate of which was 71.4%.

scholarly journals An isolated water droplet in the aqueous solution of a supramolecular tetrahedral cage

2020 ◽  
Vol 117 (52) ◽  
pp. 32954-32961
Author(s):  
Federico Sebastiani ◽  
Trandon A. Bender ◽  
Simone Pezzotti ◽  
Wan-Lu Li ◽  
Gerhard Schwaab ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Water Droplet ◽  
Solid Phase ◽  
Low Frequency ◽  
Ab Initio Molecular Dynamics ◽  
Water Molecules ◽  
Ambient Conditions ◽  
Structure And Dynamics ◽  
Thz Absorption ◽  
Low Dimensional

Water under nanoconfinement at ambient conditions has exhibited low-dimensional ice formation and liquid–solid phase transitions, but with structural and dynamical signatures that map onto known regions of water’s phase diagram. Using terahertz (THz) absorption spectroscopy and ab initio molecular dynamics, we have investigated the ambient water confined in a supramolecular tetrahedral assembly, and determined that a dynamically distinct network of 9 ± 1 water molecules is present within the nanocavity of the host. The low-frequency absorption spectrum and theoretical analysis of the water in the Ga4L612− host demonstrate that the structure and dynamics of the encapsulated droplet is distinct from any known phase of water. A further inference is that the release of the highly unusual encapsulated water droplet creates a strong thermodynamic driver for the high-affinity binding of guests in aqueous solution for the Ga4L612− supramolecular construct.

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