Photothermal bio-based membrane via spectrum-tailoring and dual H-bonding networks strategies for seawater treatment and crude oil viscosity reduction

• Spectrum-tailoring strategy for improved interfacial photothermal conversion. • Dual H-bonding networks structuring for evaporation enthalpy decreasing. • Solar-driven evaporation performance for promoting seawater treatment. • Crude oil viscosity reduction from integration of compositional interactions. To reach global carbon neutralization, the use of clean energy and biomaterials has become a trend to reduce CO 2 emission. With the increasing concerns about freshwater shortage and crude oil pollution, water purification and sewage treatment have become particularly urgent. Solar energy is an environment-friendly energy to mitigate freshwater shortage stress and reduce crude oil pollution. However, how to make solar energy applied to effectively drive freshwater generation and crude oil pollution remedy is crucial. Herein, the electrospun membrane was explored as sustainable matrix with desirable solar-to-thermal performance. The strategy of spectrum-tailoring was proposed to tailor bandgap energy of vanadium disulfide (VS 2 ) for photothermal conversion promotion and interfacial evaporation efficiency. Inspired by mussel, dopamine was polymerized on surface of VS 2 (VS 2 @PDA) for spectrum tailoring (Solar absorptance, α, is 89.34 %). Bandgap energy of the complex favorably decreased from 2.06 to 1.41 eV. Combining the dual H-bonding networks, water evaporation enthalpy of the membranes dramatically decreased from 2370 to 1990.2 J/g and the resulted evaporators showed excellent salt resistance, with evaporation rate of 1.40 kg m -2 h −1 (enhancement factor is 2.032) and extraordinary cyclic evaporation performance. Additionally, sunflower-inspired tilting model was architectured to eliminate disturbance of sun irradiation incident angles for effective solar-driven interfacial generation. The resulted membrane effectively treated the seawater and decreased high viscosity of the super-viscous crude oil under the sun irradiation, thus showing great potential in seawater treatment and crude oil pollution remedy. The designs maximized utilization of solar energy and evaporation rates by treating seawater and reducing crude oil pollution without consuming additional energy, thus contributing to carbon neutralization. Therefore, the integration of dual H-bonding networks and spectrum-tailoring strategies would facilitate the structure-functional unification and desirable photothermal capabilities, and bring about an application potential in the development of composite evaporators for carbon neutralization.