Composite nanostructured samples of Ag (0.5-20%)/(C, S)-TiO(2) were synthesized and characterized by EDX, XRD, FT-IR, UV-vis, BET, XPS, and zeta potential measurements. Photocatalytic and biocidal tests revealed that the amount of the codoped silver (Ag(+)) in (C, S)-TiO(2) played a crucial, distinctive role in the photodegradation of gas-phase acetaldehyde as well as in the inactivation of Escherichia coli cells and Bacillus subtilis spores. Very interestingly, Ag/(C, S)-TiO(2) nanoparticles (crystallite size <10 nm) have shown very strong antimicrobial properties without light activation against both E. coli (log kill >8) and B. subtilis spores (log kill >5) for 30 min exposures, compared with P25-TiO(2). Thus, for the first time, we have demonstrated that titanium dioxide (an environmentally friendly photocatalyst) codoped with silver, carbon, and sulfur can serve as a multifunctional generic biocide as well as a visible light activated photocatalyst.

Rhodium sulfide (Rh 2 S 3 ) on carbon support was synthesized by refluxing rhodium chloride with ammonium thiosulfate. Thermal treatment of Rh 2 S 3 at high temperatures (600 • C to 850 • C) in presence of argon resulted in the transformation of Rh 2 S 3 into Rh 3 S 4 , Rh 17 S 15 and Rh which were characterized by TGA/DTA, XRD, EDX, and deconvolved XPS analyses. The catalyst particle size distribution ranged from 3 to 12 nm. Cyclic voltammetry and rotating disk electrode measurements were used to evaluate the catalytic activity for hydrogen oxidation and evolution reactions in H 2 SO 4 and HBr solutions. The thermally treated catalysts show high activity for the hydrogen reactions. The exchange current densities (i o ) of the synthesized Rh x S y catalysts in H 2 -saturated 1M H 2 SO 4 and 1M HBr for HER and HOR were 0.9 mA/cm 2 to 1.0 mA/cm 2 and 0.8 to 0.9 mA/cm 2 , respectively. The intermittent availability of renewable electricity from solar and wind sources has increased significantly.1 To match their often unpredictable power generation cycles with demand, low cost electrical energy storage systems are required.A flow battery/regenerative fuel cell is an electrochemical storage device that stores the electrical energy as chemical energy in a fuel and converts the chemical energy of the fuel directly back to electrical energy. The potentially low cost and relatively rapid process of electrical-to-chemical or chemical-to-electrical energy, in comparison to the slower mechanical-to-electrical energy processes used with flywheel and compressed air storage, offers unique advantages. The discharge cycle of the flow battery utilizes a fuel cell which has proven to be efficient and clean devices for energy conversion. Fuel cells are regarded by some as the energy conversion devices of the future and provide a faster, cleaner, more efficient, and possibly more flexible chemical-to-electrical energy conversion platform than present combustion based systems. [2][3][4] In comparison to other flow battery systems, the regenerative hydrogen-bromine fuel cell has advantages including high round-trip energy conversion efficiency, high power density and storage capacity, fast kinetics of both hydrogen and bromine electrode reactions, low cost active materials, simplicity and reliability. [5][6] The core component of a H 2 /Br 2 regenerative fuel cell system is an acid-based H 2 /Br 2 fuel cell. The charge and discharge reactions occurring in the fuel cell are as follows. At the bromine electrode, during the charge cycle, bromide ions in an HBr solution are oxidized to form bromine and two electrons; require a catalyst that is highly active, to keep the performance high and the cost low, stable and durable in the highly corrosive HBr/Br 2 environment of the cell as required by the extended life of this application. During the operation of a H 2 -Br 2 fuel cell, HBr and Br 2 could cross from the bromine side through the proton conducting membrane to the hydrogen side potentially leading to the corrosion and poisoning of th...

The molecular dipole moment plays a significant role in governing important phenomena like molecular interactions, molecular configuration, and charge transfer, which are important in several electronic, electrochemical, and optoelectronic systems. Here, the effect of the change in the dipole moment of a tethered molecule on the carrier properties of (functionalized) trilayer graphene--a stack of three layers of sp(2)-hybridized carbon atoms--is demonstrated. It is shown that, due to the high carrier confinement and large quantum capacitance, the trans-to-cis isomerisation of 'covalently attached' azobenzene molecules, with a change in dipole moment of 3D, leads to the generation of a high effective gating voltage. Consequently, 6 units of holes are produced per azobenzene molecule (hole density increases by 440 000 holes μm(-2)). Based on Raman and X-ray photoelectron spectroscopy data, a model is outlined for outer-layer, azobenzene-functionalized trilayer graphene with current modulation in the inner sp(2) matrix. Here, 0.097 V are applied by the isomerisation of the functionalized azobenzene. Further, the large measured quantum capacitance of 72.5 μF cm(-2) justifies the large Dirac point in the heavily doped system. The mechanism defining the effect of dipole modulation of covalently tethered molecules on graphene will enable future sensors and molecular-machine interfaces with graphene.

Mineral acids have been used effectively for the pretreatment of cellulosic biomass to improve sugar recovery and promote its conversion to ethanol; however, substantial capital investment is required to enable separation of the acid, and corrosion-resistant materials are necessary. Disposal and neutralization costs are also concerns because they can decrease the economic feasibility of the process. In this work, three acid-functionalized nanoparticles were synthesized for pretreatment and hydrolysis of lignocellulosic biomass. Silica-protected cobalt spinel ferrite nanoparticles were functionalized with perfluoroalkylsulfonic acid (PFS), alkylsulfonic acid (AS), and butylcarboxylic acid (BCOOH) groups. These nanoparticles were magnetically separated from the reaction media and reused. TEM images showed that the average diameter was 2 nm for both PFS and BCOOH nanoparticles and 7 nm for AS nanoparticles. FTIR confirmed the presence of sulfonic and carboxylic acid functional groups. Ion exchange titration measurements yielded 0.9, 1.7, and 0.2 mmol H + /g of catalyst for PFS, AS, and BCOOH nanoparticles, respectively. Elemental analysis results indicated that PFS and AS nanoparticles had 3.1 and 4.9% sulfur, respectively. Cellobiose hydrolysis was used as a model reaction to evaluate the performance of acid-functionalized magnetic nanoparticles for breaking β-(1→4) glycosidic bonds. Cellobiose conversion of 78% was achieved when using AS nanoparticles as the catalyst at 175°C for 1 h, which was significantly higher than the conversion for the control experiment (52%). AS nanoparticles retained more than 60% of their sulfonic acids groups after the first run, and 65 and 60% conversions were obtained for the second and third runs, respectively.

We report the transformation of polydispersed dodecanethiol stabilized indium nanoparticles, obtained from bulk indium shot by evaporation/condensation solvated metal atom dispersion (SMAD) technique, into highly monodispersed partially alkyl thiolate-capped β-indiumsulfide (In(2)S(3)) by a postpreparative digestive ripening in high boiling point t-butyltoluene (190 °C) solvent. Upon digestive ripening, the as-prepared polydispersed black indium nanoparticles showed a characteristic color transition from black to cream, pale yellow, yellow, and finally to brown, indicating the transformation of the indium metal nanoparticles into intermediates composed of indium thiolates, sulfides, and polysulfides, and finally into the product In(2)S(3) nanoparticles whose surfaces are partially capped with thiolates. The transformed product (In(2)S(3)) was characterized with UV-vis, XRD, EDX, SEM, XPS, and TEM. From XRD and TEM measurements, the average size of the transformed In(2)S(3) nanoparticles is 5 nm. The optical absorbance of the as-prepared sample showed absorption peaks around 538 and 613 nm; upon digestive ripening these two peaks disappeared and stabilized at 375 nm, providing evidence of strong quantum confinement of excitons. The visible light-induced photocatalytic activity test with the In(2)S(3) nanoparticles showed that 95% of Rhodamine B (RhB) dye degraded after 100 min of irradiation with visible light.

Nearly perfect hexagonal Fe3O4 nanoplatelet structures, with edge length of 45 ± 5 nm and thickness of 5 to 6 nm were synthesized from iron(iii) acetylacetonate using the dual ligand system oleic and stearic acid.

Amphiphilic reduced graphene oxide is obtained by oleo-functionalization with epoxidized methyl oleate (renewable feedstock) using a green process. The excellent diverse solvent-dispersivity of the oleo-reduced amphiphilic graphene and its reduction chemistry are confirmed in this study. Oleo-reduction of amphiphilic graphene is amenable to industrially viable processes to produce future graphene-based polymer composites and systems.

SummaryThe quest for renewable and cleaner energy sources to meet the rapid population and economic growth is more urgent than ever before. Being the most abundant carbon source in the atmosphere of Earth, CO2 can be used as an inexpensive C1 building block in the synthesis of aromatic fuels for internal combustion engines. We designed a process capable of synthesizing benzene, toluene, xylenes and mesitylene from CO2 and H2 at modest temperatures (T = 380 to 540 °C) employing Fe/Fe3O4 nanoparticles as catalyst. The synthesis of the catalyst and the mechanism of CO2-hydrogenation will be discussed, as well as further applications of Fe/Fe3O4 nanoparticles in catalysis.