Reducing the overpotential and achieving long-term stability of electrocatalysts are vital for facilitating the catalytic activity of hydrogen evolution reaction (HER). Herein, two-dimensional dendritic PdPtCu nanosheets were prepared and further...

High overpotential and poor long‐term operation stability of electrocatalysts are two major barriers for the hydrogen evolution reaction (HER). Herein, 2D ultrathin PdAgAu nanorings are synthesized and further self‐assembled on Ti2CTx–graphene oxide (GO) heterostructure for efficiently boosting HER. The best candidate, Pd50Ag31Au19/Ti2CTx–GO electrocatalyst, can initiate hydrogen evolution at an overpotential of 90 mV at 10 mA cm−2 and exhibits the lowest Tafel slope of 75 mV dec−1 as well as the highest mass activity of 284.4 mA mg−1Pd at −100 mV, in comparison with those of Pd50Ag31Au19/Ti2CTx, Pd50Ag31Au19/GO, and commercial Pd/C. Most remarkably, impressive long‐term stability is achieved even after a 112 h chronoamperometric test. The great performance of Pd50Ag31Au19/Ti2CTx–GO electrocatalyst can be attributed to the advantageous synergistic effect among the morphological modulation, composition optimization, and strong metal–support interaction effect between the Pd50Ag31Au19 nanorings and Ti2CTx–GO support.

The detection of low‐concentration oily pollutants, especially when in oil/water mixtures or real food matrix, still faces great challenges. Integrating adsorption and plasmonic hot‐spot on single material will be an efficient method for ultra‐sensitively detecting oily dyes or contaminants in oil/water mixtures via surface‐enhanced Raman scattering. Herein, the superhydrophobic/superoleophilic polyacrylonitrile (PAN)/Ag aerogels which can quickly absorb and detect low‐concentration oily dyes in oil/water mixtures are successfully fabricated. In order to solve the contradiction that abundant hydrophilic‐Ag nanoparticles are adverse to the superhydrophobicity of substrate but in favor of Raman signals, the superhydrophobic/superoleophilic PAN/Ag aerogels are prepared through two steps: substrate‐seeding and secondary‐growth. The lowest detection concentration of 10−12 m for oil‐soluble Sudan III in oil/water mixtures is achieved by using PAN/overgrown Ag (PAN/O‐Ag) nanofibrous aerogels as absorbent, which is superior to most of reported materials. Moreover, a detection limit of 0.1 ppm of Sudan III spiked in chilli powder is obtained using PAN/O‐Ag aerogels.

The photocatalytic and inherently hydrophilic characteristic of titanium dioxide (TiO2) make it very suitable for separating oil‐in‐water emulsion and aqueous pollutants removal. However, the removal of the oily dyes in water‐in‐oil emulsion usually needs superhydrophobic/superoleophilic membranes. Although surface modification of TiO2 with fluorinated organic compounds can bring hydrophobicity, the hydrophobic surface would change back to a hydrophilic surface again after light illumination as fluorinated organic molecules are easily photodegraded too. To date, very few reports have successfully fabricated TiO2 photocatalysts keeping long‐term superhydrophobicity after repeatable photodegradation. Herein, an approach to fabricate polyvinylidene fluoride (PVDF)/polytetrafluoroethylene (PTFE) @TiO2 nanofibrous membranes through dehydrofluorination and one‐pot hydrothermal process, which possess stable superhydrophobicity in various harsh environments, is reported. For the first time, PTFE is bonded with PVDF through dehydrofluorination which induces crosslinking between PTFE and PVDF chains. Owing to the existence of PTFE, extensive hydrophobic TiO2 can be in situ grown on the rough surface of PVDF/PTFE nanofibers through one‐pot hydrothermal process. These features ensure that the membranes possess durable and high‐efficient water‐in‐oil emulsion separation and photodegradation performance. The photodegradation efficiency of the PVDF/PTFE@TiO2 membranes for oil‐soluble dyes remains above 95% even after ten cycles.