NiS₂ Nanocubes Coated Ti₃C₂ Nanosheets with Enhanced Light-to-Heat Conversion for Fast and Efficient Solar Seawater Steam Generation

Recently, 2D materials have emerged in the field of light-to-heat conversion. However, it is urgent to find a simple and effective method to reduce the light reflectivity of the 2D surface to improve the light-to-heat conversion efficiency. A 2D nano-self-assembly material coating (NiS₂@Ti₃C₂) realized by a simple hydrothermal method, which enables unique-sized nano-NiS₂ crystals and 2D Ti₃C₂–MXenes to self-assemble on a 3D scale, is innovatively proposed. Such a preparation method can construct a unique multilayer structure for multistage diffuse reflection of incident light, so that the MXene nanomaterial can achieve a light absorption rate of >90% in a wide spectral range. The composite is theoretically verified through optical simulation and first principles, and a higher light-to-heat conversion performance is achieved experimentally (61.7 °C surface equilibrium temperature, 1 sun). Compared with other similar materials, the assembled MXene seawater steam generator achieves a higher steam generation rate (1.27 kg m⁻² h⁻¹) and light-to-heat conversion efficiency (83.84%) under 1 sun. This material structure can maximize MXene active materials’ utilization and provide ideas for modifying other 2D photothermal materials.