▎ 摘　　要

Water pollution produced by various contaminants is presently a major worldwide issue, posing a significant challenge to the development of novel materials for water treatment. Herein, robust and recyclable biochar-graphene oxide (BC-GO) composite monoliths were prepared utilizing lignin precursor as a carbon source in a one-pot hydrothermal process free of hazardous chemicals. Characterization results indicated the BC-GO com-posite monolith had abundant microchannels, nanopores, and a large specific surface area, thereby exhibiting a high adsorption capacity of 796.8 mg g(-1) to doxycycline in water, which was superior to conventional adsor-bents. Furthermore, by annealing the BC-GO composite monolith, it could be transformed to hydrophobic (CA = 140 degrees). The annealed BC-GO composite monolith retained a pronounced porous structure with a larger surface area and showed exceptional absorption capabilities of 55-130 g g(-1) toward various oils and solvents, which were higher/comparable to previously reported graphene-based materials. In addition, both BC-GO composite monoliths were highly stable and could be reused for a number of cycles of pollutants removal. The simplicity, environmental friendliness, and effectiveness of our approach to building BC-GO composite monoliths may pave the way for their future applications in the field of water purification.