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The electrochemical decomposition of water plays a critical role in green and sustainable energy. However, the development of efficient and low-cost non-noble metal catalysts to overcome the high potential of the anodic oxygen evolution reaction (OER) is still challenging. In this work, electrocatalysts with high OER activity were obtained by doping Co/Fe bimetals into Ni3S2 (CF-NS) via a simple single-step hydrothermal method by adjusting the doping ratio of bimetals. A series of characterization studies revealed that the introduction of a Co/Fe co-dopant increased the number of active sites and improved the electroconductibility, while optimizing the electronic structure of Ni3S2. Meanwhile, Fe-induced high valence Ni contributed to the production of an OER active phase NiOOH. The unique dendritic crystal morphology facilitated the disclosure of the active sites and the expansion of mass transfer channels. The optimized sample required a low overpotential of 146 mV to obtain a current density of 10 mA cm−2 in 1.0 M KOH solution. The optimized sample also operated stably for at least 86 h. In sum, the proposed method looks very promising for designing efficient, stable, and low-cost non-precious metal catalysts with high conductivity and multiple active sites, useful for future synthesis of transition metal sulfide catalysts. [ABSTRACT FROM AUTHOR]

A plasmonic bimetallic nanostructure has attracted considerable attention as a promising catalyst for light-driven catalytic reactions. The stability and recovery of the catalysts are still key issues for sustainable development of green chemistry. In this work, we designed and implemented an Au/Pd heterojunction@mesoporous SiO2 yolk–shell nanostructure (Au/Pd@m-SiO2 yolk–shell NPs) for plasmon-enhanced photocatalysis. The heterojunction of Au/Pd enhances the separation of hot electrons and holes under visible light irradiation, and the mesoporous SiO2 shell protects the active Au/Pd NPs from aggregation. The Au/Pd@m-SiO2 yolk–shell NPs exhibit extremely high stability for the plasmon-enhanced catalytic reduction of p-nitrophenol (4-NP) under visible light irradiation. The merging of a plasmonic material and a yolk–shell nanostructure proposes a new way for designing catalysts with good stability and promising activity. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) water splitting offers a promising chance for energy generation on a global scale. TiO2 is a widely used photoanode material due to its superior properties and stability. However, the PEC efficiency of TiO2 is usually impeded by the fast recombination of photo-generated electron/hole pairs and the poor charge transfer ability that could be improved by band alignment and imperfection passivation, respectively. Herein, we first report that ZIF-8 is an efficient imperfection passivating layer which acts as a bifunctional cocatalyst for transferring/separating electron/hole pairs for improving the photo/photoelectrochemical performance. This work provides a new insight to investigate the charge interaction mechanism between the interface of TiO2 and ZIF-8. [ABSTRACT FROM AUTHOR]

It is a big challenge to construct proton-conductive materials for practical applications operating at high temperatures and low humidity. Herein, we propose an ionothermal strategy for the preparation of highly stable NH2-MIL-53(Al)it nanomaterials with high proton conductivity. The crystalline structure and the direct incorporation of the 1-ethyl-3-methyl-imidazolium ionic liquid within NH2-MIL-53(Al)it are identified by XRD, TG/DTA and IR techniques. The as-prepared NH2-MIL-53(Al)it exhibits a high proton conductivity of 3.0 × 10−5 S cm−1 at 80 °C and low relative humidity of ∼26%. [ABSTRACT FROM AUTHOR]

Graphene is deposited on polycrystalline Co film by radio-frequency plasma enhanced chemical vapor deposition (RF-PECVD), and the effect of deposition time on the crystallinity of graphene, such as graphitic degree and in-plane crystallite size, is explored. The findings are that graphene can be obtained on polycrystalline Co film for only 15 s, suggesting that a direct growth mechanism plays an important role in the formation of graphene. The first-principles density functional theory (DFT) results also reveal that the graphene is more easily formed on Co via a surface direct growth mechanism than that via a precipitation mechanism. Our studies are critical in guiding the graphene growth process as we try to achieve the highest quality graphene for electronic devices. [ABSTRACT FROM AUTHOR]

Graphite nanosheets have been grown on Ni foam by radio-frequency plasma-enhanced chemical vapor deposition, which are used as substrates for electrodepositon of Ni(OH)2 with a porous and 3D nanostructure. The Ni foam/graphite nanosheets/Ni(OH)2 electrode has a high specific capacitance of 1667 F g−1 and the specific capacitance can maintain 93.3% after 700 cycles at the current density of 60 A g−1 in 1 M KOH. [ABSTRACT FROM AUTHOR]

An amorphous metal-free N-doped carbon film prepared by sputtering and annealing exhibits comparable electrocatalytic activity and superior stability and methanol tolerance to the commercial Pt/C catalyst via a four-electron pathway for oxygen reduction reaction (ORR). Pyridinic nitrogen in films plays a key role in electrocatalytic activity for ORR. [ABSTRACT FROM AUTHOR]

A mild photo-assisted reduction method was developed to fabricate large-area, uniform reduced graphene oxide–TiO2films and micropatterns on various substrates in air at room temperature from a composite insulating film of graphene oxide sheets and TiO2nanoparticles, with a conductivity (0.5–2 Ω cm) comparable to chemically reduced graphene. [ABSTRACT FROM AUTHOR]