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Lead, a prevalent heavy metal, poses significant risks to human health through various exposure pathways. Herein, we propose an extremely sensitive assay toward lead ion (Pb2+) using gold nanorods (GNRs) as probes based on its catalytic activity on etching gold in the presence of 2‐mercaptoethanol and sodium thiosulfate. In the presence of Pb2+, etching predominantly occurs at the two ends of GNRs, leading to the reduction of aspect ratio and the corresponding blueshift of the localized surface plasmon resonance (LSPR). With increasing Pb2+ concentration over the range of 0–50 μM, the color of GNR solution lightens, ultimately becoming colorless. The wavelength shift (Δλ) of LSPR is highly dependent on Pb2+ concentration, with a linear regression equation of Δλ = 10.05ln[Pb2+] + 9.59 and an R2 = 0.995. The assay demonstrates high selectivity for Pb2+ over other potentially interfering ions such as Cu2+ because of its special catalytic activity in the etching of GNRs and the complexing ability of 2‐mercaptoethanol and sodium thiosulfate. Validation of the assay was accomplished by analyzing several forest‐derived food samples, affirming the accuracy in real‐world scenarios. The assay we developed holds promise for many applications in environmental protection and food safety. [ABSTRACT FROM AUTHOR]

Robust catalytic materials with high activity and stability play important roles in energy conversion and storage devices such as protonic ceramic fuel cells (PCFCs), in which a favourable cathode should possess high oxygen ion, proton and electron triple conductivities, and superior surface oxygen exchange kinetics. Herein, a thermal‐driven self‐construction phenomenon in cation‐nonstoichiometric Ba1+xGd1‐xCo2O6‐δ is reported, accordingly developing a new type of nanocomposite, that is, double perovskite BaGdCo2O6‐δ (DP‐BGCO) anchored by perovskite‐derived BaCoO3‐δ (P‐D‐BCO) nanoparticles, which, used as the cathode of PCFCs, demonstrates low area‐specific resistances of 0.053 and 0.026 ohm cm−2 respectively at 650 and 700 °C over BaZr0.3Ce0.5Y0.1Yb0.1O3‐δ protonic electrolyte and attractive peak power densities of 0.87 (650 °C) and 1.15 W cm−2 (700 °C) with outstanding stability, much superior to the similar cell with single‐phase BCO or BGCO cathodes. The synergy between the two components brings the outstanding performance with the mixed oxygen ion and electronic conducting perovskite‐derived oxide showing superior catalytic activity for oxygen reduction reaction while the double perovskite provides good bulk protonic conductivity to enlarge reaction sites. Such selective self‐construction, well manipulated through the A‐site cation stoichiometry engineering, provides a facile way for developing new high‐performance electrocatalysts with broad application potential. [ABSTRACT FROM AUTHOR]

Although they are emerging technologies for achieving high-efficiency and green and eco-friendly energy conversion, ceramic electrochemical cells (CECs), i.e. solid oxide electrolysis cells (SOECs) and fuel cells (SOFCs), are still fundamentally limited by their inferior catalytic activities at low temperature, poor thermo-mechanical stability, high material cost, etc. The materials used in electrolytes and electrodes, which are the most important components in CECs, are highly associated with the cell performances. Therefore, rational design of electrolytes and electrodes with excellent catalytic activities and high stabilities at relatively low cost is a meaningful and valuable approach for the development of CECs. Nanotechnology is a powerful tool for improving the material performances in CECs owing to the favourable effects induced by the nanocrystallization of electrolytes and electrodes. Herein, a relatively comprehensive review on the nanotechnologies implemented in CECs is conducted. The working principles of CECs and the corresponding challenges were first presented, followed by the comprehensive insights into the working mechanisms of nanocrystalline materials in CECs. Then, systematic summarization and analyses of the commonly used nano-engineering strategies in the fabrication of CEC materials, including physical and chemical methods, were provided. In addition, the frontiers in the research of advanced electrolyte and electrode materials were discussed with a special emphasis on the modified electrochemical properties derived from nanotechnologies. Finally, the bottlenecks and the promising breakthroughs in nanotechnologies were highlighted in the direction of providing useful references for rational design of nanomaterials for CECs. [ABSTRACT FROM AUTHOR]