The article reports the development of porous boron nitride nanosheets with a very high specific surface area, which exhibit excellent sorption performances for oils, solvents, and dyes. These nanosheets can absorb up to 33 times their weight in oils and organic solvents while repelling water. The saturated nanosheets can be easily cleaned for reuse by burning or heating in air due to their strong resistance to oxidation. This easy recyclability highlights the potential of porous boron nitride nanosheets for water purification and treatment. The synthesis process involves a dynamic templating approach using boron trioxide and guanidine hydrochloride, resulting in a highly porous structure with a specific surface area of 1,427 m² g⁻¹. The nanosheets show superior sorption capacities compared to commercial activated carbon and other common absorbents, making them suitable for environmental remediation applications.The article reports the development of porous boron nitride nanosheets with a very high specific surface area, which exhibit excellent sorption performances for oils, solvents, and dyes. These nanosheets can absorb up to 33 times their weight in oils and organic solvents while repelling water. The saturated nanosheets can be easily cleaned for reuse by burning or heating in air due to their strong resistance to oxidation. This easy recyclability highlights the potential of porous boron nitride nanosheets for water purification and treatment. The synthesis process involves a dynamic templating approach using boron trioxide and guanidine hydrochloride, resulting in a highly porous structure with a specific surface area of 1,427 m² g⁻¹. The nanosheets show superior sorption capacities compared to commercial activated carbon and other common absorbents, making them suitable for environmental remediation applications.