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Developing efficient Pd-based electrocatalysts is of vital importance for the application of direct alcohol fuel cells. Designing the core–shell architecture of Pd-based nanomaterials rationally has emerged as an effective strategy to promote the sluggish kinetics of anodic reactions. Herein, the PdAg alloy is reduced on a non-noble metal oxide surface for the formation of a core–shell nanostructure. The optimized SnO2@PdAghnanospheres deliver the optimal catalytic performance compared with other counterparts and commercial Pd/C. The structural investigation reveals that the introduction of Ag and formation of a PdAg/SnO2heterointerface effectively regulate the electronic structure of Pd, making SnO2@PdAgha highly active catalyst for methanol and ethylene glycol oxidation reactions. Impressively, the strong interaction between the PdAg shell and SnO2core stabilizes the metal-oxide heterointerface, contributing to the improved stability of SnO2@PdAghin electrocatalytic reactions. This study proposes the use of non-noble metal oxides as the core to suppress the dissolution of the catalysts and highlights the rational design of core@shell nanoarchitectures.

Efficient water splitting for H2evolution under visible light irradiation has attracted more attention for solving the global environmental and energy issues, but it is still a major challenge to develop an earth-abundant and efficient photocatalyst. Herein, we report two-dimensional (2D)/2D heterostructured CdS/WS2(CdS/WS2), composed of nanosheet CdS (CdS) and nanosheet WS2(WS2), as an efficient photocatalyst for H2evolution. As a noble metal-free visible light-driven catalyst for H2evolution, CdS/WS2with 10 wt % WS2exhibited the largest H2evolution rate of 14.1 mmol g–1h–1under visible light irradiation to be 8 times larger than that of pure CdS. The lifetime and dynamics of photogenerated electrons were evaluated by femtosecond time-resolved diffuse reflectance spectroscopy, indicating that WS2works as an electron-trapping site and a cocatalyst to cause H2evolution under visible light irradiation. This work suggests that CdS/WS2has great potential as a low-cost and highly efficient photocatalyst for water splitting.

In this work, Pt nanoflowers deposited on highly ordered TiO2nanotube arrays (TNTs) by modification of reduced graphene oxide (RGO) nanostructures have been synthesized. The ternary complex (Pt-TNTs/RGO) displays efficient electrocatalytic performance toward methanol oxidation in alkaline medium. The electrochemical impedance spectroscopy (EIS) and responsive photocurrent results indicate that the presence of graphene could effectively promote charge separation during electrocatalytic process. Interestingly, with assistance of visible light illumination, the electrocatalytic activity and stability of the ternary complex electrode toward methanol oxidation are distinctly improved. Both electro- and photo-catalytic processes for methanol oxidation contribute to the enhanced catalytic performance and stability. Moreover, the ternary electrode also displays efficient photoelectrocatalytic degradation of methylene blue (MB) under visible light illumination. The present work sheds light on developing highly efficient and long-term stability catalysts for methanol oxidation with assistance of visible-light illumination.

Titanium dioxide (TiO2) nanoparticles-functionalized N-doped graphene (NGR) composites (NGR/TiO2) were prepared through solvothermal treatment approach using exfoliated NGR and tetrabutyl titanate as the staring materials. The composites were characterized by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, UV–vis diffuse reflectance spectra, photoelectrochemical, and electrochemical measurements. Nitrogen doping provides favorable nucleation and anchor sites for TiO2nanocrystals formation on NGR sheets, helping to form an intimate interfacial contact between NGR and TiO2nanoparticles. Moreover, NGR has higher electrical conductivity than the reduced graphene oxide (RGO) due to the recovery of the sp2graphite network and decrease of defects, resulting in more effective charge transfer and charge separation in the NGR/TiO2composite. NGR/TiO2nanocomposite demonstrated a higher photocatalytic activity for hydrogen production as compared to its counterpart, TiO2-functionalized RGO composite (RGO/TiO2). This work provides new insights to design new more efficient graphene-based nanocomposite photocatalysts for solar energy conversion.