In literature, most of research on cellulose aerogel started from high-quality cellulose, bacterial cellulose, or wood powder [26,29,31–33]. In our study, recycled cellulose fibers (Fig. 2a) from paper waste were chosen as raw materials.
The aerogels were pre-pared using a sodium hydroxide/urea method [31,38,39] due to the low cost and convenience of the technique.