Polyamides (PAs) are regarded as attractive fluorescent polymer materials due to their nontraditional intrinsic luminescence. In this work, a series of photoluminescence active PAs were prepared from renewable furfural derivatives via the Ugi four-component polymerization. Moreover, the fluorescence of dilute PA solutions can be accurately controlled by the intramolecular hydrogen bonding interactions using the furfural module as a switch, which was finally confirmed by DFT theory. As a probe, PAs can selectively recognize Fe2+ and Fe3+ among various metal ions by the fluorescence quenching effect. This protocol provides an efficient and moderate strategy for synthesizing biobased functional polymer materials with fluorescence properties, demonstrating high synthetic efficiency and high selectivity to Fe2+ and Fe3+.

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Water pollution is a global environmental problem that has attracted great concern, and functional carbon nanomaterials are widely used in water treatment. Here, to optimize the removal performance of both oil/organic matter and dye molecules, we fabricated porous and hydrophobic core–shell sponges by growing graphene on three-dimensional stacked copper nanowires. The interconnected pores between the one-dimensional nanocore–shells construct the porous channels within the sponge, and the multilayered graphene shells equip the sponge with a water contact angle over 120° even under acidic and alkaline environments, which enables fast and efficient cleanup of oil on or under the water. The core–shell sponge can absorb oil or organic solvents with densities 40–90 times its own, and its oil-sorption capacity is much larger than those of other porous materials like activated carbon and loofah. On the other hand, the adsorption behavior of the core–shell sponge to dyes including methyl orange (MO) and malachite green (MG), also common water pollutants, was also measured. Dynamic adsorption of MG under cyclic compression demonstrated a higher adsorption rate than that in the static state, and an acidic environment was favorable for the adsorption of MO molecules. Finally, the adsorption isotherm for MO molecules was analyzed and fitted with the Langmuir model, and the adsorption kinetics were studied in depth as well.

The all‐in‐one flexible supercapacitor holds great promise for wearable electronics due to its stable electrochemical performance under continuous strain. However, it is a challenge to achieve good mechanical strength, self‐healing performance, and high energy density for their potential applications. For this purpose, a stretchable and healable all‐in‐one supercapacitor consisting of gelatin hydrogel electrolytes and polypyrrole electrodes is constructed. The gelatin hydrogel is obtained by the hydrolysis of leather waste shavings and then physically cross‐linked by simply soaking in a sodium sulfate solution. Benefiting from the Hofmeister series, the kosmotropic sodium sulfate ions can significantly enhance the hydrophobic interactions and chain bundling, thus greatly improving the mechanical strength of gelatin hydrogel. As a result, the as‐prepared all‐in‐one supercapacitor exhibits an area‐specific capacitance of 219.0 mF cm−2, a high energy density of 19.46 μWh cm−2, and long cycling life. In particular, the all‐in‐one supercapacitor can be deformed under varied stress–strain via decross‐linking and dissociation, simultaneously delivers reliable self‐healing capability. This work presents a simple and green technology to prepare an all‐in‐one supercapacitor, which motivates the development of biomass wastes toward high‐performance electronics.

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