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

Fullerene and its derivative fullerenol are in high demand for catalytic, electronic and biomedical applications. Here fullerenol with an estimated average structure of C60(OH)28·12H2O has been synthesized by a facile and scalable hydroxylation method, and distinctly, a modified purification and drying process which is hazard-free and cost-effective was employed using benzoylated dialysis tubing and lyophilizing to obtain highly pure fullerenol with high yield. More interestingly, the as-synthesized fullerenol to semi-purified fullerenol after dialysis for four days and then to fully purified fullerenol showed morphostructural transition from small and non-uniform flakes to sphere and then to perfect uniform flakes. The purified fullerenol shows tunable photoluminescence emission from violet-blue to yellowish-orange to red as we change the excitation wavelength from 240 → 285 → 350 nm. With superior optical and electronic properties, it can be made into various composites with other materials to design and develop different optoelectronic devices.