Rutin, as a biological flavonoid glycoside, has very important medicinal value. The accurate and rapid detection of rutin is of great significance. Herein, an ultrasensitive electrochemical rutin sensor based on β-cyclodextrin metal–organic framework/reduced graphene oxide (β-CD-Ni-MOF-74/rGO) was constructed. The obtained β-CD-Ni-MOF-74 was characterized by X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and nitrogen adsorption and desorption. The β-CD-Ni-MOF-74/rGO presented good electrochemical properties benefiting from the large specific surface area and good adsorption enrichment effect of β-CD-Ni-MOF-74 and the good conductivity of rGO. Under optimal conditions for the detection of rutin, the β-CD-Ni-MOF-74/rGO/GCE showed a wider linear range (0.06–1.0 μM) and lower detection limit (LOD, 0.68 nM, (S/N = 3)). Furthermore, the sensor shows good accuracy and stability for the detection of rutin in actual samples.

Herein, we prepared Pt₂CeO₂ heterojunction nanocluster (HJNS) on multiwalled carbon nanotubes (MWCNTs) in deep eutectic solvents (DESs) which is a special class of ionic liquids. The catalyst was then heat-treated at 400 °C in N₂ (refer to Pt₂CeO₂/CNTs-400). The Pt₂CeO₂/CNTs-400 catalyst showed remarkably improved electrocatalytic performance towards methanol oxidation reaction (MOR) (839.1 mA mg_Pt⁻¹) compared to Pt₂CeO₂/CNTs-500 (620.3 mA mg_Pt⁻¹), Pt₂CeO₂/CNTs-300 (459.2 mA mg_Pt⁻¹), Pt₂CeO₂/CNTs (641.6 mAmg⁻¹) (the catalyst which has not been heat-treated) and commercial Pt/C (229.9 mAmg⁻¹). Additionally, the Pt₂CeO₂/CNTs-400 catalyst also showed better CO poisoning resistance (onset potential: 0.47 V) compared to Pt₂CeO₂/CNTs (0.56 V) and commercial Pt/C (0.58 V). The improved performance of Pt₂CeO₂/CNTs-400 catalyst is attributed to the addition of appropriate CeO₂, which changed the electronic state around the Pt atoms, lowered the d-band of Pt atoms, formed more Ce-O-Pt bonds acting as new active sites, affected the adsorption of toxic intermediates and weakened the dissolution of Pt; on the other hand, with the assistance of thermal treatment at 400 °C, the obtained Pt₂CeO₂ HJNS expose more new active sites at the interface between Pt and CeO₂ to enhance the electrochemical active surface area (ECSA) and the dehydrogenation process of MOR. Thirdly, DES is beneficial to the increase of the effective component Pt(0) in the carbonization process. The study shows a new way to construct high-performance Pt-CeO₂ catalyst for the direct methanol fuel cell (DMFC).

Anode catalysts are important for direct methanol fuel cells (DMFCs) of energy conversion. Herein, we report a novel strategy by ethylene glycol-based deep eutectic solvents (EG-DESs) for the fabrication of a multi-walled carbon nanotubes (MWCNTs)-supported Pt nanoparticles catalyst (referred to as Pt/CNTs-EG-DES). The Pt/CNTs-EG-DES catalyst provides an increased electrochemically active surface area (ECSA) and shows remarkably improved electrocatalytic performance towards methanol oxidation reaction compared to Pt/CNTs-W (fabricated in water) and commercial Pt/C catalysts. The improved performance is attributed to the generation of more Pt–O bonds which change the electronic states of the Pt atoms and the special node structure that obtains more active sites for a high CO resistance. This study suggests an effective synthesis strategy for Pt-based electrocatalysts with high performance for DMFC applications.

In this study, the Pd₃Co₁ alloy nanocluster from a multiwalled carbon nanotube (MWCTN) catalyst was fabricated in deep eutectic solvents (DESs) (referred to Pd₃Co₁/CNTs). The catalyst shows a better mass activity towards the formic acid oxidation reaction (FAOR) (2410.1 mA mg_Pd⁻¹), a better anti-CO toxicity (0.36 V) than Pd/CNTs and commercial Pd/C. The improved performance of Pd₃Co₁/CNTs is attributed to appropriate Co doping, which changed the electronic state around the Pd atom, lowered the d-band of Pd, formed a new Pd-Co bond act at the active sites, affected the adsorption of the toxic intermediates and weakened the dissolution of Pd; moreover, with the assistance of DES, the obtained ultrafine Pd₃Co₁ nanoalloy exposes more active sites to enhance the dehydrogenation process of the FAOR. The study shows a new way to construct a high-performance Pd-alloy catalyst for the direct formic acid fuel cell.

The detection of dopamine is of great significance for human health. Herein, Pd nanoparticles were loaded on Cu nanoplates (Pd/Cu NPTs) by a novel liquid phase reduction method. A novel dopamine (DA) electrochemical sensor based on the Pd NPs/Cu/glass carbon electrode (Pd/Cu NPTs/GCE) was constructed. This sensor showed a wide linear range of 0.047 mM to 1.122 mM and a low limit of detection (LOD) of 0.1045 μM (S/N = 3) for DA. The improved performance of this sensor is attributed to the obtained tiny Pd nanoparticles which increase the catalytic active sites and electrochemical active surface areas (ECSAs). Moreover, the larger surface area of two–dimensional Cu nanoplates can load more Pd nanoparticles, which is another reason to improve performance. The Pd/Cu NPTs/GCE sensor also showed a good reproducibility, stability, and excellent anti–interference ability.

In recent years, cadmium sulfide (CdS) has been widely investigated due to its excellent photocatalytic performance. However, its practical application in pollutant treatment is limited by its narrow photoresponse range and susceptibility to photocorrosion. Herein, we design a unique four-layer core–shell structure NaYF₄:Yb³⁺,Er³⁺@NaYF₄@CdS@Au (CSNPs@CdS@Au), with an inert NaYF₄ shell coating on NaYF₄:Yb³⁺,Er³⁺ (CNPs) to form NaYF₄:Yb³⁺,Er³⁺@NaYF₄ (CSNPs) and CdS depositing on CSNPs (CSNPs@CdS); Au nanoparticles are loaded on CdS (CSNPs@CdS@Au). Compared with CdS (9.81%), CSNPs (5.0%), CSNPs/CdS (6.9%), and CSNPs@CdS (81.0%), CSNPs@CdS@Au degrades 97.7% Rhodamine B (RhB) within 15 min, exhibiting superior photocatalytic performance, attributable to two key factors: (1) the NaYF₄ inert shell encapsulation amplifies upconversion (UC) luminescence intensity by suppressing surface quenching; and (2) the electron transfer between Au nanoparticles and CdS effectively promotes spatial separation of photogenerated charge carriers and increases reactive active sites. Additionally, after five degradation cycles, CSNPs@CdS@Au still maintains a 93.25% degradation rate for RhB, confirming its excellent stability. This remarkable stability is attributed to the uniquely designed multilayer core–shell architecture, which significantly enhances structural integrity through physical isolation effects. This study establishes a material preparation strategy for efficient photocatalytic pollutant degradation.