A facile approach for in situ synthesis of graphene-branched-Pt hybrid nanostructures with excellent electrochemical performance

Dissimilitude behaviour of Cu2O nano-octahedra and nano-cubes towards photo- and electrocatalytic activities

Nano-octahedra are photocatalytically active for the removal of organic contaminants of water, whereas nanocubes are electrocatalytically active towards oxygen reduction reactions.

Synergistically Improving the Activity, Antipoisonous Ability, and Long-Term Stability of Pt to Methanol Oxidation through Developing Favorable Graphene-Based Supports

An interconnected framework of reduced graphene oxide/phenyl formaldehyde polymer composites was synthesized by a one-pot hydrothermal reaction followed by carbonizing under different conditions. Then, the obtained porous materials with varied surface properties were used to disperse ultrasmall Pt nanoparticles. The catalyst with the optimized support demonstrates superior achievements to methanol oxidation reaction (MOR): distinctive improved mass activity (MA) and specific activity at both forward peak position and at the potential range near the operation of fuel cells, best antipoisonous ability revealed by 17 times MA and 7 times the retaining rate of commercial Pt/C in chronoamperometric evaluations, and outstanding long-term stability verified by 3-4 times MA and the retaining rate of Pt/C in the accelerated duration tests. By analyzing the performances of all studied catalysts, we proposed that fruitful oxygen groups and defects on the surface of supporting materials play a key role in boosting the MOR fulfillments through strengthening the Pt-substrate interaction or facilitating the removal of CO from the Pt surface. Elimination of surface oxygen groups and defects may promote the conductivity and mechanical strength of the catalysts but could result in a serious deterioration of antipoisonous ability, which means that only if the deliberate balance is achieved in the preparation of supporting materials can the MOR performances of Pt be improved synergistically.

Shape and Composition Effects on Photocatalytic Hydrogen Production for Pt-Pd Alloy Cocatalysts

The shape and composition effects of platinum-palladium (Pt-Pd) alloy nanoparticle cocatalysts on visible-light photocatalytic hydrogen evolution from an aqueous ammonium sulphite solution have been reported and discussed. The activity of Pt-Pd nanoparticles loaded Pt-Pd/CdS photocatalysts are affected based on both the Pt-Pd alloy nanoparticles' shape and their compositions. In this research, two shapes of Pt-Pd nanoparticles have been studied. One is Pt-Pd nanocubes enclosed by {100} crystal planes and the other is nano-octahedra covered with {111} crystal facets. Results show that the photocatalytic turnover frequency (TOF), defined as moles of hydrogen produced per surface mole of Pt-Pd metal atom per second, for Pt-Pd nanocubes/CdS (Pt-Pd NCs/CdS) photocatalyst can be 3.4 times more effective than Pt-Pd nano-octahedra/CdS (Pt-Pd NOTa/CdS) nanocomposite photocatalyst. Along with the shape effect, the atomic ratio of Pt to Pd can also impact the efficiency of Pt-Pd/CdS photocatalysts. When the Pt to Pd atomic ratio changes from 1:0 to about 2:1, the rate of hydrogen production increases from 900 μmol/h for Pt NCs/CdS catalyst to 1837 μmol/h for Pt-Pd (2:1) NCs/CdS photocatalyst-a 104% rate increase. This result suggests that the 33 mol % of more expensive Pt can be replaced with less costly Pd, resulting in a more than 100% hydrogen production rate increase. The finding of this research will lead to the research and development of highly effective catalysts for photocatalytic hydrogen production using solar photonic energy.

Self-assembly synthesis of reduced graphene oxide-supported platinum nanowire composites with enhanced electrocatalytic activity towards the hydrazine oxidation reaction

Pt-NWs-P can self-assemble on the GO@NH₂ surface. After NaBH₄ reduction, Pt-NWs/RGO show improved electrocatalytic activity for the hydrazine oxidation reaction.

Shear-force-dominated dual-drive planetary ball milling for the scalable production of graphene and its electrocatalytic application with Pd nanostructures

We employed simple shear-force-dominated planetary ball milling to prepare graphene on a large scale (200 g per cycle) with less structural defects.

A facile approach for the synthesis of copper(ii) myristate strips and their electrochemical activity towards the oxygen reduction reaction

Copper(ii) myristate strips, an inexpensive, straight chain compound of copper act as active electrocatalyst in oxygen reduction reaction.

Highly porous Pd nanostructures and reduced graphene hybrids: excellent electrocatalytic activity towards hydrogen peroxide

A new approach has been developed for highly porous Pd nanostructure–graphene hybrids as efficient electrocatalysts towards reduction of H₂O₂.

Enhanced catalytic performance of Pd–Pt nanodendrites for ligand-free Suzuki cross-coupling reactions

The Pd–Pt NDs were synthesized by a one-pot wet-chemical method, which showed enhanced catalytic activity toward Suzuki cross-coupling reaction.

Facile synthesis of Ag nanowire–rGO composites and their promising field emission performance

Crystalline, ultra long silver nanowires, few-layered rGO and their rGO–Ag NW nanocomposite have been synthesized using a polyol reflux technique under optimized experimental conditions.

Pt–CeO2/reduced graphene oxide nanocomposite for the electrooxidation of formic acid and formaldehyde

The Pt–CeO₂/reduced graphene oxide nanocomposite on the carbon-ceramic electrode (Pt–CeO₂/RGO/CCE) was prepared by a two-step electrodeposition process.

Seed-assisted synthesis of Pd@Au core-shell nanotetrapods and their optical and catalytic properties

The synthesis of noble metal nanostructures with special morphology, structure, composition, and size has been an attractive research area because of their valuable applications in various fields, including optics, electronics, sensing and catalysis. In this work, the first Pd@Au core-shell nanotetrapods (Pd@Au CSNTPs) were synthesized through a facile seeded growth method. Specifically, Pd nanotetrapods were utilized as the substrate for Au coating through chemically reducing HAuCl4 with ascorbic acid (AA) in the presence of polyvinylpyrrolidone (PVP). The morphology, composition, and structure of Pd@Au CSNTPs were fully characterized by scanning and transmission electron microscopy, energy dispersive spectroscopy element mapping, X-ray powder diffraction, X-ray photoelectron spectroscopy techniques, etc. Different from conventional spherical Au nanoparticles, the Pd@Au CSNTPs had a very wide surface plasmon resonance (SPR) absorption band in the visible and near-infrared regions (500-1400 nm), showing special SPR absorption features. Meanwhile, the Pd@Au CSNTPs exhibited remarkably enhanced catalytic activity for the hydrogenation reduction of nitro functional groups and the C=N bond because of their specific structural characteristics.

Platinum nanocatalysts loaded on graphene oxide-dispersed carbon nanotubes with greatly enhanced peroxidase-like catalysis and electrocatalysis activities

A powerful enzymatic mimetic has been fabricated by employing graphene oxide (GO) nanocolloids to disperse conductive carbon supports of hydrophobic carbon nanotubes (CNTs) before and after the loading of Pt nanocatalysts. The resulting GOCNT-Pt nanocomposites could present improved aqueous dispersion stability and Pt spatial distribution. Unexpectedly, they could show greatly enhanced peroxidase-like catalysis and electrocatalysis activities in water, as evidenced in the colorimetric and electrochemical investigations in comparison to some inorganic nanocatalysts commonly used. Moreover, it is found that the new enzyme mimetics could exhibit peroxidase-like catalysis activity comparable to natural enzymes; yet, they might circumvent some of their inherent problems in terms of catalysis efficiency, electron transfer, environmental stability, and cost effectiveness. Also, sandwiched electrochemical immunoassays have been successfully conducted using GOCNT-Pt as enzymatic tags. Such a fabrication avenue of noble metal nanocatalysts loaded on well-dispersed conductive carbon supports should be tailored for the design of different enzyme mimics promising the extensive catalysis applications in environmental, medical, industrial, and particularly aqueous biosensing fields.