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Covalent functionalization of tungsten disulfide (WS2) with photo‐ and electro‐active nickel‐porphyrin (NiP) is reported. Exfoliated WS2 interfacing NiP moieties with 1,2‐dithiolane linkages is assayed in the oxygen evolution reaction under both dark and illuminated conditions. The hybrid material presented, WS2−NiP, is fully characterized with complementary spectroscopic, microscopic, and thermal techniques. Standard yet advanced electrochemical techniques, such as linear sweep voltammetry, electrochemical impedance spectroscopy, and calculation of the electrochemically active surface area, are used to delineate the catalytic profile of WS2−NiP. In‐depth study of thin films with transient photocurrent and photovoltage response assays uncovers photo‐enhanced electrocatalytic behavior. The observed photo‐enhanced electrocatalytic activity of WS2−NiP is attributed to the presence of Ni centers coordinated and stabilized by the N4 motifs of tetrapyrrole rings at the tethered porphyrin derivative chains, which work as photoreceptors. This pioneering work opens wide routes for water oxidation, further contributing to the development of non‐noble metal electrocatalysts. [ABSTRACT FROM AUTHOR]

While cobaloximes have been protagonists in the molecular (photo)catalytic hydrogen evolution reaction field, researchers originally shed light on the catalytically active metallic center. However, the specific chemical environment of cobalt, including equatorial and axial ligation, has also a strong impact on the catalytic reaction. In this article, we aim to demonstrate how pyridine vs. imidazole axial ligation of a cobaloxime complex covalently grafted on graphene affects the hydrogen evolution reaction performance in realistic acidic conditions. While pyridine axial ligation mirrors a drastically superior electrocatalytic performance, imidazole exhibits a remarkable long-term stability. [ABSTRACT FROM AUTHOR]

Abstract: Achieving stability with highly active Ru nanoparticles for electrocatalysis is a major challenge for the oxygen evolution reaction. As improved stability of Ru catalysts has been shown for bulk surfaces with low‐index facets, there is an opportunity to incorporate these stable facets into Ru nanoparticles. Now, a new solution synthesis is presented in which hexagonal close‐packed structured Ru is grown on Au to form nanoparticles with 3D branches. Exposing low‐index facets on these 3D branches creates stable reaction kinetics to achieve high activity and the highest stability observed for Ru nanoparticle oxygen evolution reaction catalysts. These design principles provide a synthetic strategy to achieve stable and active electrocatalysts. [ABSTRACT FROM AUTHOR]

Front Cover: Tungsten Disulfide-Interfacing Nickel-Porphyrin For Photo-Enhanced Electrocatalytic Water Oxidation (ChemSusChem 8/2023) This exciting and novel transition metal dichalcogenide-based material has exhibited outstanding electrocatalytic behavior for the oxygen evolution reaction in an alkaline environment, close to that of the state-of-the-art, noble metal-based, commercial electrocatalysts. Keywords: chalcogenides; electrocatalysis; photocatalysis; porphyrinoids; water splitting EN chalcogenides electrocatalysis photocatalysis porphyrinoids water splitting 1 1 1 04/25/23 20230421 NES 230421 B The Front Cover b shows a hybrid, nano-electrocatalyst consisting of exfoliated tungsten disulfide, decorated with nickel porphyrin moieties connected to its backbone via dithiolane-based linkages. [Extracted from the article]

Sulfur-doped carbon nanohorns (S-CNHs) were prepared by an easy one-pot solvothermal process and were employed as efficient electrocatalysts towards water splitting. Initially, oxidation of CNHs followed by thermal treatment with the Lawesson's reagent resulted in the formation of S-CNHs with the sulfur content determined as high as 3%. The S-CNHs were thoroughly characterized by spectroscopic, thermal and electron microscopy imaging means and then electrocatalytically screened. Specifically, S-CNHs showed excellent activity and durability for both O2 and H2 evolution reactions, by showing low overpotential at 1.63 and −0.2 V vs. RHE for oxygen and hydrogen evolution reaction, respectively. Additionally, S-CNHs showed significantly lower Tafel slope value and lower current resistance compared to oxidized and pristine CNHs for both electrocatalytic reactions. The outstanding electrocatalytic properties and high conductivity, along with the high S-doping level, render S-CNHs a promising bifunctional electrocatalyst for water splitting. [ABSTRACT FROM AUTHOR]

[Display omitted] • Wrapping of the cores with the shell was continuously varied and characterized. • Strained, defective shell and charge transfer from the core enable activation of the basal plane. • An optimal hybrid structure led to improved activity. • The hybrids are potent catalysts towards HER, and ORR. The development of noble-metal free electrocatalysts is of high importance for clean energy conversion applications. MoS 2 has been considered as a promising low-cost catalyst for the hydrogen evolution reaction (HER), however its activity is limited by poor conductivity and low abundance of active sites. Moreover, its suitability as an effective catalyst for other reactions, in particular the oxygen reduction reaction (ORR), was hardly explored to date. Herein, we show hybrid nanostructures of shelled CuS particles with MoS 2 layers, which produces several outcomes: The MoS 2 shell is strained and defective, and charge transfer from the core to MoS 2 occurs, enabling activation of the basal plane of MoS 2. Changing the feed ratio of the precursors led to control over morphology, such that the wrapping of the cores with the shell was continuously varied and characterized. We found an optimal hybrid structure, which provided high electrochemical active surface area and fast charge transfer kinetics, leading to improved activity not only towards HER (overpotential of 225 mV at 10 mA cm−2), but also for the sluggish ORR (onset potential 0.87 V vs RHE). [ABSTRACT FROM AUTHOR]