Robust and Elastic Bioinspired MXene-Coated Foams with Enhanced Energy Storage and Conversion Capabilities

Constructing highly porous structures using Ti3C2Tx MXene provides a promising strategy toward achieving low density, high specific surface area, and shorter ion/molecule transport paths. However, the weak MXene-MXene or MXene-substrate interactions hinder the development of ultra-robust and elastic MXene-based architectures. To address this issue, a bio-inspired strategy is developed to effectively adhere the MXene nanosheets onto melamine foam via covalent and hydrogen bonding interactions through polyethyleneimine/polydopamine-modification. The enhanced interactions contribute to high MXene loading (approximate to 94 wt.%) and reversible compressibility even after 10 000 compression/release cycles at 80% strain. The compressible supercapacitor device assembled from this foam exhibits high energy storage capability (119 F g(-1) at 2 mV s(-1)) with capacitance retention of approximate to 93% after 1000 compression/release cycles at 50% strain. Moreover, the presence of polydopamine and MXene enable the absorption of light in the UV-vis and near-IR regions, respectively, inducing photothermal conversion functionality, with an evaporation rate of approximate to 1.5 kg m(-2) h(-1) and approximate to 89% solar evaporation efficiency under one sun illumination. It is envisaged that this bio-inspired chemical modification offers a versatile strategy for the assembly of MXene nanosheets onto different substrates for various applications, such as electromagnetic interference shielding, energy storage, and conversion.

Automated summary

Constructing highly porous structures using Ti3C2Tx MXene provides a promising strategy for achieving low density, high specific surface area, and shorter ion/molecule transport paths. However, weak interactions between MXene layers or between MXene and substrates hinder the development of robust and elastic MXene-based architectures. To overcome this challenge, a bio-inspired strategy is developed to effectively adhere MXene nanosheets onto melamine foam using covalent and hydrogen bonding interactions through polyethyleneimine/polydopamine-modification. The enhanced interactions enable high MXene loading and reversible compressibility, and the resulting foam exhibits high energy storage capability and photothermal conversion functionality.