In the realm of soil management, nanotechnology holds promising and tremendous potential for improving food security and ensuring sustainability.

Developing green 3D porous materials integrating multitasking environmental remediation with high efficiency and reusability is considered to be a promising sustainable approach and is urgently required. Herein, we have successfully prepared a facile, ecofriendly, and robust multifunctional composite sponge of carbon nitride (CN) nanosheets wrapping an elastomer polydimethylsiloxane (PDMS) skeleton without harsh treatments. The composite sponge ([email protected]) exhibits excellent hydrophobic and superoleophilic properties with a water contact angle of 133.2°. This sponge also shows high selective absorption of organic solvents and oils with high recyclability after 10 absorption cycles. Furthermore, the [email protected] sponge has a high ability for demulsification of the oil-in-water emulsion as well. The as-prepared sponge displays high thermal stability, retaining 82.16% of its original weight up to 550 °C, and extraordinary prolonged stability in harsh corrosive solutions over 35 h compared with the pristine PDMS sponge. Additionally, the [email protected] sponge exhibits a high ability for adsorption and photodegradation of rhodamine B under visible light irradiation with self-cleaning and high reusability over 5 runs. Such a sustainable strategy would provide new ways for broad environmental applications.

Fabrication of few-layered polymeric carbon nitride (PCN) photocatalysts have attracted increasing attention owing to their substantial enhancement of the photocatalytic performance. A green strategy for the synthesis of ultrathin PCN nanosheets with integration of high-efficiency and enriched active edges using minimimal chemicals and energy input is overwhelmingly required and is still challenging. Herein, we report a green, cost-effective and template-free synthesis approach for ultrathin foam-like PCN nanosheets with enriched active sites in a wet atmosphere via a “three-in-one” strategy. This strategy relies on coupling of melem segments, polymerization with condensed layers, delamination by water molecules, and introduction of new terminal groups entirely in one-pot without any other additives. The obtained melem-derived PCN (MFCN-wet) shows highly loose and extremely light characteristics with the formation of ultrathin few-layers. Furthermore, it exhibits a high specific surface area and pore volume. Most importantly, the enriched active sites with fast charge carrier transfer drastically enhance the hydrogen evolution rate and rhodamine B (RhB) degradation with a high stability under visible light irradiation, compared with that of the as-synthesized materials in nitrogen and air atmospheres. This sustainable strategy could provide new opportunities for further environmental and energy applications.