A feasible strategy is demonstrated here for low-cost and rapid synthesis of nanosheet-structured BaCO3 spheres (NSBCs) on a large scale. Experiments reveal that NSBCs were developed from amorphous precursor under the mediation of phosphate. Their nanosheet-composed structures facilitate the rapid removal of contaminant of Cr(VI) within 60 min from aqueous solution, showing an excellent adsorption capacity (q (m,cal) = 227 mg/g, T = 298 K). The kinetic and isotherm processes confirmed well to the pseudo-second-order model and Langmuir adsorption model, respectively. Thermodynamic analysis indicated that the adsorption process was spontaneous and endothermic. NSBCs show better Cr(VI) removal behaviour compared with commercial and some synthetic barium carbonate, which may have potential application in water treatment.