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A self-supported silver electrode was prepared by plasma spraying and used for catalysing the hydrogen evolution reaction. Thanks to the non-equilibrium synthetic conditions, the silver catalyst exposes high-energy (200) crystal planes, which enhance the adsorption of hydrogen and improve the intrinsic catalytic activity. As a result, the silver catalyst delivers an overpotential of 349 mV at 10 mA cm−2, which was much lower than those of Ag foil (742 mV) and commercial Ag powder (657 mV). This work provides a new idea of preparing active electrocatalysts by traditional processes. [ABSTRACT FROM AUTHOR]

Elemental doping has been proved to be an efficient approach to adjust the performance of NiFe layered double hydroxides (NiFe LDHs) for water oxidation. However, the mechanism by which elemental doping affects catalytic activity remains unclear. Herein, we doped NiFe LDH with the Mn element and investigated the effect of elemental doping on the electronic structure of NiFe LDH and oxygen evolution reaction (OER) performance. Operando X-ray absorption spectroscopy analysis indicates that Mn doping promotes the formation of Ni(IV) ions. Density functional theory calculations reveal that Mn doping causes hybridization between Ni 3d and O 2p orbitals which facilitates the oxidation of Ni(II) ions. Resultantly, more active Ni(IV) sites could be generated at a lower applied voltage, which is beneficial for the OER performance. [ABSTRACT FROM AUTHOR]

Ultrathin nanosheets attract considerable attention with regard to both fundamental research and potential applications. Nevertheless, non-layer structured materials are hard to make into nanosheets due to their isotropous bonds in three dimensions. Herein, ultrathin Cd4S5 nanosheets were synthesized via chemical vapor deposition followed by chemical etching. These nanosheets show the thinnest thickness (1 nm) and largest lateral size (10 μm) among those reported for CdS materials so far. As a catalyst for photocatalytic hydrogen production, ultrathin Cd4S5 nanosheets achieve a high apparent quantum efficiency of 4.15% under 420 nm light irradiation. The superior photocatalytic performance is ascribed to the unique structure (surface S− anions and a reconstructed surface structure), and the ultrathin structure endows 1 nm NSs with long-term durability. This work opens a new avenue for producing two-dimensional nanostructures of non-layered compounds and improving their photocatalytic properties. [ABSTRACT FROM AUTHOR]

FeCo2O4 nanoparticles with abundant oxygen vacancies were produced by laser fragmentation. The oxygen vacancies can lower the thermodynamic energy barriers as well as accelerate the electron transfer, eventually promoting oxygen evolution and reduction reactions simultaneously. [ABSTRACT FROM AUTHOR]

Zinc oxide is a cost-efficient and eco-friendly material for solar-to-chemical energy conversion. However, the relatively wide band gap and poor stability restrict its practical applications. Herein, we report on the modification of ZnO nanosheets with a porous atomically thin ZnS overlayer. The as-prepared ZnS/ZnO/ZnS sandwich nanosheets exhibit a reduced band gap (2.72 eV) and yet a slightly elevated conduction band minimum, which remarkably broadens the wavelength range for light absorption and generates electrons with enough reducing capability. At the same time, the newly-prepared sandwich nanosheets possess alternatively exposed ZnS and ZnO surface patches, which attract and accommodate photo-generated holes and electrons, respectively. In addition, the ZnS overlayer catalyzes and accelerates hole-consumption reactions, thus preserving electrons for efficient water splitting. As a result, the ZnS/ZnO/ZnS sandwich nanosheets demonstrate intensive light absorption, fast charge separation, long electron lifetime, and eventually the highest hydrogen production rate reported for oxide catalysts so far. This work proves that passivation with an ultrathin layer is a potent approach for energy-band engineering, and semiconductor sandwich nanostructures are promising for highly efficient water splitting under sunlight. [ABSTRACT FROM AUTHOR]

CdSe nanowires (NWs) were grown in solution under microwave irradiation with the catalysis of solid gold nanoparticles, following a solution–solid–solid (SSS) mechanism. The monocrystal CdSe nanowires distributed evenly on fluorine doped tin oxide (FTO) glass, exhibited intensive light absorption and degraded methyl blue efficiently. [ABSTRACT FROM AUTHOR]

Introduction of lattice strain into catalysts is a facile way to modify catalytic behaviour. Here, we report the synthesis of Pd nanoparticles with compressive strain by pulsed laser ablation of a Pd target immersed in an aqueous solution. The intensive quenching effect induces obvious compressive strain which improves the ORR performance of the Pd nanoparticles significantly. [ABSTRACT FROM AUTHOR]

Mesocrystals are known to be unusual materials derived from the self-assembly of nanoparticles. However, their advantages arising from their unique structure have not been fully exploited to date owing to hindrance by a secondary phase. Herein, we employ a pulsed laser to synthesize mesocrystalline cupric oxide (CuO) with pure phase and clean surface. A gas sensor based on a CuO mesocrystal exhibits the highest sensitivity, the fastest response, and the best selectivity ever reported towards ethanol. Our study elucidates the inherent characteristics of mesocrystals and clears doubts regarding their practicability. [ABSTRACT FROM AUTHOR]

Cadmium chalcogenide nanocrystals (CCNCs) are regarded as promising materials for photoelectrochemical (PEC) water splitting. However, the relatively low PEC response and poor stability restrict their practical applications. In the present work, we demonstrate that a well-designed inverse opal structure (IOS) composed of CCNCs can achieve an unprecedentedly high photocurrent and hydrogen production rate. In particular, the IOS electrode remains stable during 3 h of continuous illumination, which is even superior to those photoanodes with surface passivation and/or co-catalysts. Quantitative investigation reveals that the IOS possesses high charge-separation efficiency and light-absorption capacity, which eventually result in excellent PEC performance. [ABSTRACT FROM AUTHOR]

FeCo2O4 nanoparticles with abundant oxygen vacancies were produced by laser fragmentation. The oxygen vacancies can lower the thermodynamic energy barriers as well as accelerate the electron transfer, eventually promoting oxygen evolution and reduction reactions simultaneously.