This Perspective is focused on the photocatalytic activity of gold nanoparticles supported titania (Au/TiO(2)). Titania most widely used photocatalyst, but its limited under visible light irradiation has motivated quest for modified materials absorbing light. The review starts by justifying how doping with metallic elements a related strategy, different, to that leading use Au/TiO(2) in photocatalysis. Data supporting and confirming photoactivity colloidal solutions are briefly presented...

When irradiated with visible light (λ > 400 nm) 1 wt % gold-supported ceria nanoparticles generate oxygen from water (10.5 μmol·h–1) more efficiently than the standard WO3 (1.7 even under UV irradiation (9.5 μmol·h–1). This remarkable photocatalytic activity arises a novel preparation method to reduce particle size of (5 by means electrostatic binding Ce4+ alginate gel, subsequent supercritical CO2 drying, and calcination. The low loading Au is crucial for observed high catalytic activity.

Chitosan is a N-containing biopolymer that can form high-quality films on glass, quartz, metals and other hydrophilic surfaces. Pyrolysis of chitosan under argon at 800 °C inert atmosphere gives rise to single layer N-doped graphene (over 99% transmittance) as evidenced by XPS, Raman spectroscopy, TEM imaging.

Richtig dotiert: Phosphordotiertes Graphen wurde durch die Pyrolyse von natürlichem, mit H2PO4− versetztem Alginat bei 900 °C erhalten. Dieses Material katalysierte Erzeugung Wasserstoff aus einer Wasser/Methanol-Mischung Bestrahlung UV- oder sichtbarem Licht. Wurde Menge an eingesetztem erhöht, eine höhere photokatalytische Aktivität beobachtet.

MoS2 is a promising material to replace Pt-based catalysts for the hydrogen evolution reaction (HER), due its excellent stability and high activity. In this work, nanoparticles supported on graphitic carbon (about 20 nm) with preferential 002 facet orientation have been prepared by pyrolysis of alginic acid films quartz containing adsorbed (NH4)2MoS4 at 900 °C under Ar atmosphere. Although some variation electrocatalytic activity has observed from batch batch, sample exhibited HER (a...

The present critical review focuses on the production of C4, C5 diols and monoalcohols from precursors derived biomass.

Clean and green: Copper(I) complexes of phenanthroline-based ligands anchored on the chitosan polymer are good catalysts for "click" cycloaddition azides with terminal alkynes (see scheme; scanning electron microscopy image shows porous structure catalyst). These heterogeneous catalytic systems do not require a base or reducing agent operate in alcohol water.

Abstract There is much current interest in developing graphene‐based materials as photocatalysts, particularly the field of solar fuels and photocatalytic generation hydrogen. Graphene a versatile material allowing different modification strategies to improve its activity. Thus, present manuscript we report that, contrast lack activity undoped graphene, nitrogen doping introduces UV‐ visible‐light for hydrogen evolution; efficiency depends on preparation conditions. The N‐doped graphene...

Ruthenium nanoparticles supported on titania are over three times more active than conventional ruthenium carbon for the hydrogenation of lactic acid. This superior catalytic activity can be due to a combined action small and support.

Nitrogen (N)-, boron (B)-, and boron,nitrogen (B,N)-doped graphene (G) act as carbocatalysts, promoting the aerobic oxidation of benzylic positions aromatic hydrocarbons cyclooctane to corresponding alcohol/ketone mixture with more than 90 % selectivity. The most active material was co-doped (B,N)G, which, in absence solvent a substrate/(B,N)G ratio 200, achieved 50 tetralin conversion 24 h selectivity 80 %. An FT-Raman spectroscopic study sample (B,N)G heated at 100 °C presence oxygen...

Macroporous catalyst was obtained by dispersing nanosized gold in the fibrils of chitosan matrix, followed CO(2) supercritical drying resulting hybrid material. The accessible nanoparticles are highly active for carbon-carbon cross coupling reactions.

Development of renewable fuels from solar light appears as one the main current challenges in energy science. A plethora photocatalysts have been investigated to obtain hydrogen and oxygen water last decades. However, photon-to-hydrogen molecule conversion is still far allowing real implementation fuels. Here we show that 111 facet-oriented gold nanoplatelets on multilayer graphene films deposited quartz a highly active photocatalyst for simulated sunlight overall splitting into absence...

Reduced graphene oxide exhibits high activity as Fenton catalyst with HO(.) radical generation efficiency over 82 % and turnover numbers of 4540 15023 for phenol degradation H2 O2 consumption, respectively. These values compare favorably those achieved transition metals, showing the potential carbocatalysts reaction.

A general methodology to prepare MXene quantum dots (MxQDs) with yields over 20% by liquid-phase laser ablation of the MAX phase is reported. Mechanical and thermal shock 532 nm pulses (7 ns fwhp, 50 mJ × pulse-1 , 1 Hz pulse frequency) produces etching exfoliation form QDs, avoiding use HF. The process can be followed absorption emission spectroscopy dynamic scattering it appears general, being applied Ti3 AlC2 Ti2 AlC, Nb2 V2 AlC phases. Density functional theory calculations indicate...

Four MXene dots (MDs) (Ti3C2, Ti2C, V2C and Nb2C) have been prepared by laser ablation of the corresponding MAX phases in aqueous medium subsequent separation double centrifugation. These MDs were characterized atomic force transmission electron microscopy that show, respectively, thickness between 3 7.5 nm to few-layer nanoparticles homogeneous lateral dimensions 2.5 5 with high crystallinity. IR spectroscopy indicates Ti3C2 Ti2C contain OH as surface terminal groups, while XPS presence O...

Abstract Carbon spheres from natural biopolymers (alginate and chitosan) are easily synthesised by thermal treatment between 400 800 °C under an inert atmosphere. All the samples, including untreated biopolymers, as well resulting carbon materials, exhibit a remarkable CO 2 ‐adsorption capacity. The sample that exhibits highest adsorption capacity was obtained carbonisation of alginate at subsequent with KOH °C. This material specific surface area 765 m g −1 , micropore volume 0.367 cm 3...

This work describes a simple procedure to obtain hybrid materials based on palladium alginate acting as heterogeneous catalysts for the Suzuki carbon−carbon coupling reactions. When reacted with Na2PdCl4, carboxylate groups of matrix act chelating agent Pd cations, which in turn behave gelling support. During further steps preparation, cations spontaneously reduce metallic species, and metal nanoparticles are obtained, homogeneously highly dispersed biopolymer matrix. CO2 supercritical...

Abstract The present manuscript describes a simple, efficient and environmentally friendly room temperature aqueous catalytic approach to the selective preparation of sulfoxides from sulfides utilising low‐loaded supported iron oxide nanoparticles hydrogen peroxide as oxidant. Materials could be easily recovered reaction mixture reused ten times without any loss in activity no metal leaching was observed during reaction. This is thus first oxidation using an iron‐based heterogeneous system.