A Room-Temperature Postsynthetic Ligand Exchange Strategy to Construct Mesoporous Fe-Doped CoP Hollow Triangle Plate Arrays for Efficient Electrocatalytic Water Splitting

Small ◽  
2018 ◽  
Vol 14 (14) ◽  
pp. 1704233 ◽  
Author(s):  
Enlai Hu ◽  
Jiqiang Ning ◽  
Dian Zhao ◽  
Chunyang Xu ◽  
Yingying Lin ◽  
...  
Keyword(s):  
Water Splitting ◽  
Ligand Exchange ◽  
Room Temperature

Water-induced hydrogenation of graphene/metal interfaces at room temperature: Insights on water intercalation and identification of sites for water splitting

Nano Research ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 3101-3108 ◽  
Author(s):  
Guangyu He ◽  
Qi Wang ◽  
Hak Ki Yu ◽  
Daniel Farías ◽  
Yingchun Liu ◽  
...  
Keyword(s):  
Water Splitting ◽  
Room Temperature ◽  
Metal Interfaces

scholarly journals Supramolecular Frameworks Based on Rhenium Clusters Using the Synthons Approach

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2662
Author(s):  
Nathalie Audebrand ◽  
Antoine Demont ◽  
Racha El Osta ◽  
Yuri V. Mironov ◽  
Nikolay G. Naumov ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Crystal Structures ◽  
Ligand Exchange ◽  
Alkaline Earth ◽  
Room Temperature ◽  
Hydration Rate ◽  
Rhenium Cluster ◽  
New Compounds ◽  
Cluster Unit

The reaction of the K4[{Re6Si8}(OH)a6]·8H2O rhenium cluster salt with pyrazine (Pz) in aqueous solutions of alkaline or alkaline earth salts at 4 °C or at room temperature leads to apical ligand exchange and to the formation of five new compounds: [trans-{Re6Si8}(Pz)a2(OH)a2(H2O)a2] (1), [cis-{Re6Si8}(Pz)a2(OH)a2(H2O)a2] (2), (NO3)[cis-{Re6Si8}(Pz)a2(OH)a(H2O)a3](Pz)·3H2O (3), [Mg(H2O)6]0.5[cis-{Re6Si8}(Pz)a2(OH)a3(H2O)a]·8.5H2O (4), and K[cis-{Re6Si8}(Pz)a2(OH)a3(H2O)a]·8H2O (5). Their crystal structures are built up from trans- or cis-[{Re6Si8}(Pz)a2(OH)a4−x(H2O)ax]x−2 cluster units. The cohesions of the 3D supramolecular frameworks are based on stacking and H bonding, as well as on H3O2−bridges in the cases of (1), (2), (4), and (5) compounds, while (3) is built from stacking and H bonding only. This evidences that the nature of the synthons governing the cluster unit assembly is dependent on the hydration rate of the unit.

Hexagonal Phase Ni 3 Fe Nanosheets toward High‐Performance Water Splitting by a Room‐Temperature Methane Plasma Method

2021 ◽  
pp. 2109709
Author(s):  
Guijuan Wei ◽  
Yongli Shen ◽  
Xixia Zhao ◽  
Ying Wang ◽  
Weiqing Zhang ◽  
...  
Keyword(s):  
Water Splitting ◽  
High Performance ◽  
Room Temperature ◽  
Hexagonal Phase ◽  
Plasma Method

scholarly journals Correction: One pot ligand exchange method for a highly stable Au–SBA-15 catalyst and its room temperature CO oxidation

2018 ◽  
Vol 54 (91) ◽  
pp. 12892-12892
Author(s):  
Yogita Soni ◽  
I. Kavya ◽  
T. G. Ajithkumar ◽  
C. P. Vinod
Keyword(s):  
Co Oxidation ◽  
Ligand Exchange ◽  
Room Temperature ◽  
One Pot ◽  
Exchange Method

Correction for ‘One pot ligand exchange method for a highly stable Au–SBA-15 catalyst and its room temperature CO oxidation’ by Yogita Soni et al., Chem. Commun., 2018, DOI: 10.1039/c8cc06887a.

Ligand Redistribution Equilibria in Aqueous Fluoroberyllate Solutions

1998 ◽  
Vol 53 (11) ◽  
pp. 1294-1300 ◽  
Author(s):  
Michael Schmidt ◽  
Hubert Schmidbaur
Keyword(s):  
Experimental Data ◽  
Ligand Exchange ◽  
Room Temperature ◽  
Chemical Shifts ◽  
Equilibrium Constants ◽  
Individual Species ◽  
Ph Values ◽  
Exchange Processes ◽  
The Individual ◽  
Good Agreement

The composition of aqueous fluoroberyllate solutions has been studied by 9Be and 19F NMR spectroscopy for various ratios of the beryllium and fluorine concentrations, and at different pH values. The equilibrium constants have been determined for the ligand exchange processes, which involve the species [Be(OH2)4]2+, [BeF(OH2)3]+, [BeF2(OH2)2], [BeF3(OH2)]- , and [BeF4]2-. These equilibria are shifted towards [BeF4]2- at high pH. No polynuclear fluoroberyllates have been detected. The fluoride exchange between the individual species is slow on the NMR time scale at room temperature, and separate sharp signals with the expected multiplicity are therefore recorded. Calculated 9Be chemical shifts are in good agreement with experimental data.

The elusive [Ni(H2O)2(15-crown-5)]2+ cation and related co-crystals of nickel(II) hydrates and 15-crown-5

2008 ◽  
Vol 64 (6) ◽  
pp. 725-737 ◽  
Author(s):  
Maxime A. Siegler ◽  
Sean Parkin ◽  
John P. Selegue ◽  
Carolyn Pratt Brock
Keyword(s):  
Hydrogen Bonds ◽  
Ligand Exchange ◽  
Room Temperature ◽  
Target Compound ◽  
Synthetic Routes ◽  
Pale Green

Initial attempts to make [Ni(H2O)2(15-crown-5)](NO3)2, i.e. to insert the Ni2+ ion into the 15-crown-5 macrocycle, gave the mono- (two polymorphs) and dihydrate of a co-crystal of [Ni(H2O)6](NO3)2 and 15-crown-5 (1,4,7,10,13-pentaoxacyclopentadecane = 15C5). Synthetic routes designed to restrict the water available to the Ni2+ cation gave three additional compounds, [Ni(H2O)6](NO3)2-trans-[Ni(H2O)4(MeOH)2](NO3)2·2(15C5), cis-[Ni(H2O)4(NO3)2]-trans-[Ni(H2O)4(NO3)2]·2(15C5) and [Ni(H2O)2(MeCN)(NO3)2]·15C5·MeCN. All five compounds contain Ni2+ ions with two trans aqua ligands. In all six structures these aqua ligands make hydrogen bonds to the 15C5 molecules to form stacks in which the Ni complexes and 15C5 molecules alternate. The structures are surprisingly complicated: all are co-crystals, some are also solvates, and most have Z′ > 1. The target compound was finally prepared by heating pale green crystals of [Ni(H2O)6](NO3)2·15C5·2H2O to over 350 K and then cooling the resulting mixture of yellow crystals and solution to room temperature. Formation of the target compound seems to be favored at higher temperatures by a positive Δrxn S o and an increased rate of ligand exchange.

Room temperature synthesis of a highly active Cu/Cu2O photocathode for photoelectrochemical water splitting

2016 ◽  
Vol 4 (36) ◽  
pp. 13736-13741 ◽  
Author(s):  
Zexun Jin ◽  
Zhuofeng Hu ◽  
Jimmy C. Yu ◽  
Jianfang Wang
Keyword(s):  
Water Splitting ◽  
Room Temperature ◽  
Photoelectrochemical Water Splitting ◽  
Temperature Synthesis ◽  
Room Temperature Synthesis ◽  
Highly Active

A Cu2O photocathode with excellent PEC performance was fabricated by a simple comproportionation reaction between Cu0 and Cu2+.

scholarly journals Transport properties in nanostructured thermoelectric materials and single crystal perovskites

2021 ◽  
Author(s):  
◽  
Michael Ng
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Single Crystal ◽  
Single Crystals ◽  
Thermoelectric Properties ◽  
Thermoelectric Materials ◽  
Ligand Exchange ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Surface Degradation

<p>Energy consumption worldwide is constantly increasing, bringing with it the demand for low cost, environmentally friendly and efficient energy technologies. One of these promising technologies is thermoelectrics in which electric power is harvested from waste heat energy. The efficiency of a thermoelectric device is determined by the dimensionless figure of merit ZT = σS²T/k where σ is the electrical conductivity, S is the thermopower, k is the thermal conductivity, and T is the average temperature. In this thesis we investigate the use of nanostructuring, which has been known to lead to significant reduction in the lattice thermal conductivity to maximise the figure of merit.  One of the most successful bulk thermoelectric materials is Bi₂Te₃, with a ZT of unity at room temperature. Here we investigate the effects of nanostructuring on the thermoelectric properties of Bi₂Te₃. Sub-100 nm ₂Te₃ nanoparticles were successfully synthesized and the figure of merit was found to be ZT ~ 5X10⁻⁵ at room temperature. The effect of a ligand exchange treatment to replace the long chain organic ligand on the as-synthesized nanoparticles with a short chain alkyl ligand was explored. After ligand exchange treatment with hydrazine the figure of merit of sub-100 nm Bi₂Te₃ was found to increase by two fold to ZT ~ 1X10⁻⁴ at room temperature. Overall the figure of merit is low compared to other nanostructured Bi₂Te₃, this was attributed to the extremely low electrical conductivity. The thermopower and thermal conductivity were found to be ~96 μVK⁻¹ and ~0.38 Wm⁻¹ K⁻¹ at 300 K respectively, which show improvements over other nanostructured Bi₂Te₃.  Further optimisation of the figure of merit was also investigated by incorporating Cu, Ni and Co dopants. The most successful of these attempts was Co in which 14.5% Co relative to Bi was successfully incorporated into sub-100 nm Bi₂Te₃. The figure of merit of nanostructured Bi₁.₇₁Co₀.₂₉Te₁.₇₁ alloy was found to increase by 40% to a ZT ~ 1.4X10⁻⁴ at room temperature. Although overall the figure of merit is low, the effect of Co alloying and hydrazine treatment shows potential as a route to optimise the figure of merit.  A potential novel material for thermoelectrics applications is inorganicorganic perovskite single crystals. Here we report a synthetic strategy to successfully grow large millimetre scale single crystals of MAPbBr₃₋xClx, FAPbBr₃₋xClx, and MAPb₁-xSnxBr₃ (MA = methylammonium and FA = formamidinium) using inverse temperature crystallisation (ITC) in a matter of days. This is the first reported case of mixed Br/Cl single crystals with a FA cation and mixed Pb/Sn based perovskites grown using ITC. The bandgap of these single crystals was successfully tuned by altering the halide and metal site composition. It was found that single crystals of FAPbBr₃₋xClx were prone to surface degradation with increased synthesis time. This surface degradation was observed to be reversible by placing the single crystals in an antisolvent such as chloroform.  A tentative model was proposed to analyse the IV characteristics of the single crystal perovskites in order to extract mobilities and diffusion lengths. The MAPbBr₃ and MAPbBr₂.₅Cl₀.₅ single crystal mobilities were found to be between 30-390 cm² V⁻¹ s⁻¹ and 10-100 cm² V⁻¹ s⁻¹ respectively, the diffusion lengths were found to be between 2-8 μm and 1-4 μm respectively. This is an improvement over polycrystalline thin film perovskites and comparable to other single crystal perovskites. The conductance of MAPb₁-xSnxBr₃ based perovskites was found to increase by 2 orders of magnitude even with just 1% of Sn incorporated. The thermal conductivity of MAPbBr₃ single crystals was found to be ~1.12 Wm⁻¹ K⁻¹ at room temperature which is reasonable low for single crystals, however no other thermoelectric properties could be measured due to the self cleaving nature of the single crystals with decreasing temperature and the high resistivity of the material.</p>

An advanced and highly efficient Ce assisted NiFe-LDH electrocatalyst for overall water splitting

2020 ◽  
Vol 4 (1) ◽  
pp. 312-323 ◽  
Author(s):  
Harsharaj S. Jadhav ◽  
Animesh Roy ◽  
Bezawit Z. Desalegan ◽  
Jeong Gil Seo
Keyword(s):  
Water Splitting ◽  
Current Density ◽  
Room Temperature ◽  
Cell Voltage ◽  
Highly Efficient ◽  
Overall Water Splitting ◽  
A Cell ◽  
A Current

A room-temperature synthesized NiFeCe2 electrocatalyst delivered a current density of 10 mA cm−2 at a cell voltage of 1.59 V when used as the electrolyzer.

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