MOF-Assisted Catalytic Laser-Induced Pyramid-Array Graphene on Biomass for Efficient Solar Desalination

Solar-driven interfacial evaporators from biomass provide a sustainable solution for freshwater production, yet their deployment is often constrained by inefficient light harvesting, limited purification capability, and the lack of eco-friendly fabrication processes. Herein, we integrate multifunctional ZIF-67 with natural rattan to develop a MOF-assisted catalytic laser-induced graphitization (CLIG) strategy that converts rattan surfaces into pyramid-array graphene architectures under ambient conditions, simultaneously achieving in-situ graphitization, surface micro-structuring, and functional integration. During laser irradiation, ZIF67@phosphate catalytic complexes create a transient protective microenvironment that promotes sp²-hybridized carbon assembly while suppressing oxidative degradation, yielding a seamlessly integrated pyramid-array graphene-based photothermal layer with multi-dimensional light harvest, broadband solar absorption and high photothermal conversion efficiency (96.72 %). ZIF-67 imparts multifunctionality by catalytically assisting local graphitization and scavenging volatile byproducts during laser treatment, while potentially contributing to evaporation-enthalpy reduction through modification of the confined interfacial water environment. The pyramid-array topology induces dual-Marangoni convection to accelerate water replenishment and effectively suppress salt crystallization. Coupled with rattan’s intrinsic bimodal vascular network, the resulting evaporator achieves efficient solar desalination with rapid self-cleaning for long-term stable operation. This work establishes a scalable strategy that bridges catalytic photothermal chemistry and biomass valorization, showing promise for broader lignocellulosic substrates in sustainable solar desalination.