3D porous cellulose/polyaniline aerogel composite as a high-performance electrode for selective electrosorption of...

Compared with traditional extraction processes, adsorption methods are generally limited by bottlenecks such as low capacity and slow rate when treating actual feed solutions containing low-concentration rhenium. In this study, a three-dimensional porous cellulose nanofiber/polyaniline aerogel (CNF/PANI) was designed and constructed via the hydrogen bond crosslinking between PANI and CNF, derived from cellulose extracted from spent mushroom substrates (a waste biomass). Featuring an economical and environmentally friendly synthesis route, it possesses a three-dimensional porous network structure that can accommodate abundant active sites. Upon the application of an external electric field, the material exhibits excellent adsorption capacity and kinetics, enabling the specific, efficient, and rapid adsorption of rhenium from actual feed solutions, and used as a high-efficiency anode adsorbent. Driven by an external potential of 1.2 V, CNF/PANI can significantly improve the adsorption capacity and rate for rhenium, enabling rapid and high-capacity recovery of low-concentration rhenium. Electrochemical tests have shown that the charge storage mechanism of CNF/PANI-2 is dominated by the synergy of pseudo-capacitance and double-layer capacitance, with high specific capacitance, low resistance, and excellent cycling stability, endowing it with efficient ion transport efficiency and reusability. Under this mechanism, electrochemical adsorption capacity reached 938.62 mg g^-1(1.2 V, pH=4, 323 K, 25 mL min^-1), significantly increasing by 3.6 times compared to static adsorption, achieving a synergistic breakthrough in adsorption rate and capacity. Mechanism analysis reveals that the enhanced Re(Ⅶ) adsorption is due to the synergistic effect of electrochemical adsorption and chemical adsorption. This aerogel demonstrates exceptional efficiency in recovering Re(Ⅶ) from industrial wastewater, thereby exhibiting significant potential for resource recovery and waste minimization applications.