A novel approach for green synthesis of cellulose nanorods as optical sensor support for ultra-detection and recovery of precious metals from electronic wastes

Abstract

Using the metal retrieved from e-waste recycling to make new products is an important industrial consideration. To address this pressing issue, we must create a fast, simple, selective, accurate, efficient, and cost-effective method of monitoring of Hg2+, Pd2+, and Au3+ ions in electronic wastes. An innovative approach to responding to this challenge is the construction of a sticklike architecture composed of the newly developed nanocellulose that is synthesized via green synthesis. The sticklike design of the prepared nanocellulose has a large surface area, making it an ideal mesoporous substrate for loading the chromophore 4,4′- bis(dimethylamino)- thiobenzophenone (DMATB). The fabricated chemosensor and parent nano cellulose base were characterized using FE-SEM, HR-TEM, XPS, N2 adsorption isotherms, and XRD analysis to identify their morphology. The solution pH, contact time, temperature, selectivity, and sensitivity were optimized to evaluate the best sensing performance to achieve naked-eye detection with a low concentration of Hg2+, Pd2+, and Au3+ ions. Moreover, the DMATB chemosensor showed an impressive sensitivity of 0.167 ppb (8.35×10−10 M), 0.177 ppb (1.67×10−9 M), and 0.15 ppb (7.63×10−10 M) towards Hg2+, Pd2+, and Au3+ ion respectively. It is undoubtedly clear that these DMATB chemosensor present a powerful way of identifying Hg2+, Pd2+, and Au3+ ions in both tap water and E-waste. The adsorption capacity of the DMATB chemosensor was 73.2, 62.6, and 64.3 mg of Hg2+, Pd2+, and Au3+ per gram, respectively. Highlighting its potential for effective extraction and repurposing of palladium and gold from e-waste.