Bismuth vanadate (BiVO4) is proven to be a promising photocatalyst for water splitting. However, the effect of materials syntheses, electrode preparation and size of photoelectrode on the ...photocurrent output of BiVO4 photoanodes needs further investigations. In
this study, three different BiVO4 nanoparticle synthesis were employed, namely hydrothermal (HT), HT in the presence of ethylene glycol (EG) and HT with the addition of hydrazine hydrate (HH). In addition, two molecular inks (Triton-X and ethyl‐methyl‐imidazole, EMI),
were compared for the preparation of BiVO4 photoanodes using a simple doctor-blade technique followed by calcination at 450°C. The photoanodes (9 cm2 active surface) were then compared for their photocurrent density at AM1.5G illumination and 1.2 V (vs. standard
hydrogen electrode (SHE)) bias in a specifically designed, three-dimensional (3D)-printed electrochemical cell. The highest photocurrent 0.13 ± 0.1 mA cm‐2 was obtained with the EMI ink, whereas tenfold lower photocurrent was obtained with Triton-X due to the higher
charge transfer resistance, measured by electric impedance spectroscopy (EIS). The photoresponse was reproducible and relatively stable, with only 8% decrease in five consecutive illumination periods of 1 min.
This Minireview summarises the most relevant work on sulfur‐containing systems and provides direction towards the preparation of novel photoactive materials. This contribution overviews the synthesis ...of sulfur‐containing organic ligands and metal complexes and their incorporation in surfaces, nanoparticles and frameworks, with the aim to highlight the most relevant applications of such materials. We focus on the use of sulfur‐containing anchoring groups to prepare advanced materials, although examples in which thiols provide decisive properties are also included, for example, stabilization of gold nanoparticles. From these, we provide a series of research directions that we and others are currently exploring to prepare new photoactive materials containing sulfur. These materials will take advantage of the plasmonic properties of thiol‐capped gold and silver nanoparticles and their use to enhance energy‐conversion technologies.
See the light: This Minireview summarises recent examples of sulfur‐containing materials (in fields such as photocatalysis, porous materials, semiconductors, self‐assembled monolayers and molecular wires) and provides key aspects to develop new photoactive materials using a molecular‐level approach. A clear advantage of sulfur‐containing materials is their conducting properties through metal–sulfur bonds.
Sunlight-driven green hydrogen production is emerging as a promising contribution to carbon emission reduction, for which semiconductors as water splitting photocatalysts have arisen as potential ...materials to reach the worldwide climate goals at a low cost. As photoanode materials for oxygen evolution reaction (OER), bismuth-containing semiconducting metal oxides, such as BiVO4, Bi2WO6 and Bi2MoO6, have shown convincingly visible-light-driven photocatalytic activities due to their well-matching band gaps and redox potentials of valence/conduction band positions (1). In particular, BiVO4 demonstrated formidable photocatalytic performance for water splitting (2). However, BiVO4 often suffers from fast recombination of the photo-generated electron-hole pairs, which limits the electron flow in photoelectrochemical cells (3).
The first artificially made set of electron acceptors is presented that are derived from a unique platform Cs3,3′‐Co(C2B9H11)2, for which the redox potential of each differs from its predecessor by a ...fixed amount. The sequence of electron acceptors is made by substituting one, two, or more hydrogen atoms by chlorine atoms, yielding Cs3,3′‐Co(C2B9H11−yCly)(C2B9H11−zClz). The higher the number of chlorine substituents, the more prone the platform is to be reduced. The effect is completely additive, so if a single substitution implies a reduction of 0.1 V of the redox potential of the parent complex, then ten substitutions imply a reduction of 1 V.
It all adds up! The first artificially made set of electron acceptors derived from a unique platform, Cs3,3′‐Co(C2B9H11)2, each differing from the predecessor by a fixed potential, is presented. The sequence of electron acceptors is made by substituting one, two or more hydrogen atoms with chlorine atoms. The effect is additive so that each substitution implies, on average, a 0.1 V anodic shift.
Seeing I to I: The reaction of a weakly coordinating carboranyl phosphane ligand with I2 leads to the formation of an adduct containing the bridging P⋅⋅⋅II⋅⋅⋅P assembly in the solid state (see ...picture; I purple, P orange, C gray, B pink, H white). DFT calculations combined with a variety of experimental techniques suggest that this structural motif also exists in solution.
A great parallel exists between metal complexes of cyclopentadienyl and arene ligands on one side and metal complexes of the nido derivatives of the icosahedral o-carborane clusters. With few ...exceptions, the metal complexation in the cluster can be viewed as the substitution of one or more bridging hydrogen atoms by the metal. Therefore, a necessary requirement for the complexation is the deprotonation of the nido cluster to generate a coordination site for that metal. The reaction to remove these protons, which most probably is one of the most commonly done processes in boron and metallaborane chemistry, is barely known, and no quantitative data are available on the magnitude of their pKa values. With the purpose of determining the acidity of nido-carboranes, a procedure to calculate the pKa values of nido boron clusters is presented in this paper for the first time. To this objective, some nido clusters have been selected and their geometry and NMR-spectroscopic properties have been studied, giving a good correlation between the theoretical and experimental data in both geometry distances and 11B NMR spectroscopy. Of notice is the result that proves that the singular carbon atom in the thermodynamic isomer of C2B10H13- is definitely part of the cluster and that its connection with the C2B3 face would be better defined by adding additional interactions with the two boron atoms nearest to the second cluster carbon. The pKa values of the nido species have been calculated by correlating experimental pK(a) values and calculated reaction Gibbs energies DeltaG(s). Some pKa values of importance are -4.6 and +13.5 for 7,8-C2B9H13 (1) and 7,8-C2B9H12- (2), respectively.
Als Sandwich serviert: Das Cobaltabisdicarbollid (Mono‐)Anion (3,3′‐Co(1,2‐C2B9H11)2−, COSAN−) bildet bei niedrigen Konzentrationen in Wasser aus Monoschichten bestehende Vesikel (siehe Bild). Eine ...Erhöhung der Konzentration führt zu einer Coulomb‐Explosion der dicht gepackten Vesikel in kleinere Micellen. Dadurch koexistieren beide Aggregate bei höheren Konzentrationen.
The industrial adoption of microbial electrosynthesis (MES) is hindered by high overpotentials deriving from low electrolyte conductivity and inefficient cell designs. In this study, a mixed ...microbial consortium originating from an anaerobic digester operated under saline conditions (∼13 g L
NaCl) was adapted for acetate production from bicarbonate in galvanostatic (0.25 mA cm
) H-type cells at 5, 10, 15, or 20 g L
NaCl concentration. The acetogenic communities were successfully enriched only at 5 and 10 g L
NaCl, revealing an inhibitory threshold of about 6 g L
Na
. The enriched planktonic communities were then used as inoculum for 3D printed, three-chamber cells equipped with a gas diffusion biocathode. The cells were fed with CO
gas and operated galvanostatically (0.25 or 1.00 mA cm
). The highest production rate of 55.4 g m
d
(0.89 g L
d
), with 82.4% Coulombic efficiency, was obtained at 5 g L
NaCl concentration and 1 mA cm
applied current, achieving an average acetate production of 44.7 kg MWh
. Scanning electron microscopy and 16S rRNA sequencing analysis confirmed the formation of a cathodic biofilm dominated by
sp. Finally, three 3D printed cells were hydraulically connected in series to simulate an MES stack, achieving three-fold production rates than with the single cell at 0.25 mA cm
. This confirms that three-chamber MES cells are an efficient and scalable technology for CO
bio-electro recycling to acetate and that moderate saline conditions (5 g L
NaCl) can help reduce their power demand while preserving the activity of acetogens.
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