On high purity fullerenol obtained by combined dialysis and freeze-drying method with its morphostructural transition and photoluminescence

•Green, simple and inexpensive purification technique for high purify fullerenol.•Achieved higher yield, scalability, and rapid recovery using benzoylated dialysis and lyophilization.•Morphological transition to rugged structure.•Displayed tunable optoelectronic properties from the high purity fullerenol.