Integrated electrochemical identification and detoxification of chromium oxyanion by dual amino functionalized carboxymethyl cellulose material

Precise identification and detoxification of chromium pollution is important in effectively safeguarding ecological security and human health, while achieving the dual objectives of pollution prevention and resource regeneration. Herein, we synthesized dual-amine-functionalized carboxymethyl cellulose (CMC) material to develop a non-metal based integrated electrochemical process for centralized Cr(VI) detection, adsorption and reduction. Polyethyleneimine (PEI) and 5-aminosalicylic acid (5-ASA) were selected as amine-functionalizing additives. PEI was primarily employed to construct a three-dimensional network structure, optimizing mass transfer during the electrochemical process. 5-ASA, which possessed more negative electrostatic potential, greatly enhanced the adsorption capacity and reducibility of CMC by promoting electron transfer, changing the surface chemical environment and reducing the energy barrier of reduction reaction. The adsorption of Cr(VI) (354.6 mg/g) was dominated by charge attraction, chelation and electrostatic attraction interactions, while the reduction of chromium (54 %) was triggered by electrochemical and electro reduction process. The electrode also exhibited a Cr(VI) detection sensitivity of 0.00256 μA/ppb and limit of 1.2471 ppb, respectively. This research developed a metal-free environmentally friendly electrochemical material for advancing the efficiency and intelligence of environmental management.