Oxyanion-Sensitive Catalytic Activity of Ni(II)/Oxyanion Systems for Heterogeneous Organic Degradation: Differential Oxidizing Capacity of Ni(III) and Ni(IV) as High-Valent Intermediates.

This study demonstrated that NiO and Ni(OH) as Ni(II) catalysts exhibited significant activity for organic oxidation in the presence of various oxyanions, such as hypochlorous acid (HOCl), peroxymonosulfate (PMS), and peroxydisulfate (PDS), which markedly contrasted with Co-based counterparts exclusively activating PMS to yield sulfate radicals. The oxidizing capacity of the Ni catalyst/oxyanion varied depending on the oxyanion type. Ni catalyst/PMS (or HOCl) degraded a broad spectrum of organics, whereas PDS enabled selective phenol oxidation.

Preparation of Practical High-Performance Electrodes for Acidic and Alkaline Media Water Electrolysis.

The synthesis of electrocatalyst and the electrode preparation were merged into a one-step process and proved to be a versatile method to synthesize metal oxide electrocatalysts on the conductive carbon paper (CP). Very simply, the metal precursor deposited on the CP was thermally treated by a torch-gun for just 6 s, resulting in the formation of RuO , Co O , and mixed oxide nanoparticles. The material could be directly used as working electrode for oxygen evolution reaction (OER).

A Highly-Efficient Oxygen Evolution Electrocatalyst Derived from a Metal-Organic Framework and Ketjenblack Carbon Material.

The composite of the metal-organic framework (MOF) Ni(Fe)-MOF-74 and the highly conductive carbon material ketjenblack (KB) could be easily obtained from the in-situ MOF synthesis in a one-step solvothermal reaction. The composite material features a remarkable electrochemical oxygen evolution reaction (OER) performance where the overpotential at 10 mA/cm and the current density at 1.7 V are recorded as 0.

In situ total scattering experiments of nucleation and crystallisation of tantalum-based oxides: from highly dilute solutions via cluster formation to nanoparticles.

The exact formation mechanism of tantalum oxides (and in general, metal/mixed metal oxides) from alkoxide precursors is still not fully understood, particularly when forming cluster-like or amorphous materials. The structural evolution of Ta-based oxides was studied in detail using X-ray total scattering experiments along with subsequent pair distribution function (PDF) analyses. Starting from a tantalum alkoxide precursor (Ta(OEt)), the formation of hydrolysed TaOH clusters in highly diluted aqueous solution was analysed.

Dual Role of Silver Moieties Coupled with Ordered Mesoporous Cobalt Oxide towards Electrocatalytic Oxygen Evolution Reaction.

Herein, we show that the performance of mesostructured cobalt oxide electrocatalyst for oxygen evolution reaction (OER) can be significantly enhanced by coupling of silver species. Various analysis techniques including pair distribution function and Rietveld refinement, X-ray absorption spectroscopy at synchrotron as well as advanced electron microscopy revealed that silver exists as metallic Ag particles and well-dispersed Ag O nanoclusters within the mesostructure. The benefits of this synergy are twofold for OER: highly conductive metallic Ag improves the charge transfer ability of the electrocatalysts while ultra-small Ag O clusters provide the centers that can uptake Fe impurities from KOH electrolyte and boost the catalytic efficiency of Co-Ag oxides.

Ag(I) ions working as a hole-transfer mediator in photoelectrocatalytic water oxidation on WO film.

Ag(I) is commonly employed as an electron scavenger to promote water oxidation. In addition to its straightforward role as an electron acceptor, Ag(I) can also capture holes to generate the high-valent silver species. Herein, we demonstrate photoelectrocatalytic (PEC) water oxidation and concurrent dioxygen evolution by the silver redox cycle where Ag(I) acts as a hole-transfer mediator.

How g-CN Works and Is Different from TiO as an Environmental Photocatalyst: Mechanistic View.

Graphitic carbon nitride (CN) as a popular visible light photocatalyst needs to be better understood for environmental applications. The behaviors of CN as an environmental photocatalyst were systematically studied in comparison with a well-known TiO photocatalyst. The two photocatalysts exhibit different photocatalytic oxidation (PCO) behaviors and dependences on the experimental conditions (e.

Highly Active Cobalt-Based Electrocatalysts with Facile Incorporation of Dopants for the Oxygen Evolution Reaction.

In situ formation of electroactive cobalt species for the oxygen evolution reaction is simply achieved by applying an anodic bias to a commercially available cobalt precursor and Nafion binder mixture coated on a glassy carbon electrode. This preparation does not require energy-intensive materials preparation steps or noble metals, yet a low overpotential of 322 mV at 10.2 mA cm and a high current density of more than 300 mA cm at 1.

Selective dual-purpose photocatalysis for simultaneous H2 evolution and mineralization of organic compounds enabled by a Cr2O3 barrier layer coated on Rh/SrTiO3.

Dual-functional photocatalysis for H2 evolution with the simultaneous mineralization of 4-chlorophenol was achieved under de-aerated conditions using a Cr2O3/Rh/SrTiO3 photocatalyst which has Rh nanoparticles covered with a thin Cr2O3 barrier layer to selectively control and maximize the dual-functional photocatalytic activity.

Molecular-level understanding of the photocatalytic activity difference between anatase and rutile nanoparticles.

The generation of oxidants on illuminated photocatalysts and their participation in subsequent reactions are the main basis of the widely investigated photocatalytic processes for environmental remediation and selective oxidation. Here, the generation and the subsequent diffusion of (·)OH from the illuminated TiO2 surface to the solution bulk were directly observed using a single-molecule detection method and this molecular phenomenon could explain the different macroscopic behavior of anatase and rutile in photocatalysis. The mobile (·)OH is generated on anatase but not on rutile.

Catalytic templating approaches for three-dimensional hollow carbon/graphene oxide nano-architectures.

We report a catalytic templating method to synthesize well-controlled three-dimensional carbon nano-architectures. Depending on graphene oxide content, the morphology can be systematically tuned from layered composites to 3D hollow structures to microporous materials. The composites with high surface area and high porosity induce a significant enhancement to its capacitance at high current density.