Fabrication of 3D self−supported MoS2–Co–P/nickel foam electrode for adsorption−electrochemical removal of Cr(Ⅵ). (October 2022)

• Record Type: Journal Article
• Authors: Shen, Lidong; Ding, Wenchen; Li, Xuchun; Zhang, Yi; Cong, Yanqing
• Is Part Of: Chemosphere. Volume 304(2022)
• Publication Date: 2022-10
• Subjects: adsorption−electrocatalysis -- 3D pine−needle−like nanorods and flower−like nanosheets -- MoS2–Co–P/NF -- Cr(Ⅵ) removal; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.135209
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Electrochemistry is considered to be one of the most efficient and environment−friendly methods for removing highly toxic Cr (Ⅵ). In this study, a 3D self−supported MoS2 –Co–P/nickel foam (NF) electrode was prepared via a calcination−hydrothermal process to remove the Cr (Ⅵ) in aqueous medium. Scanning electron microscope (SEM) analysis indicated that the pine−needle−like Co2 P nanoneedle and flower−like MoS2 nanosheets were successfully loaded on the three−dimensional (3D) framework of NF, which provided abundant active sites. The electrode modified by Co, P and MoS2 exhibited high removal efficiency of Cr (Ⅵ) (96.9%) at pH 3.0, current of 0.128 mA and voltage of 2.5 V. Co, P and MoS2 have the synergistic promotion on the catalytic performance of electrodes, and the reduction efficiency of Cr (Ⅵ) was greatly improved by 127.5 times relative to pure NF. The enhanced removal of Cr (Ⅵ) was related to the coupling effect of adsorption and electrocatalytic reduction. The mechanism study indicated that electron (e − ) is the active species of Cr (Ⅵ) reduction. The Cr (Ⅵ) removal rate was maintained at 90 ± 1% after five successive cycle experiments, demonstrating good stability and potential industrial applications of MoS2 –Co–P/NF. Graphical abstract: Image 1 Highlights: 3D self-supported MoS2 –Co–P/NF electrode was prepared by a simple two-step method. Cr (Ⅵ) removal rate can reach 96.9% at the initial concentration of 50 mg/L. P, Co and MoS2 have the synergistic promotion on catalytic performance of electrodes. MoS2 –Co–P/NF exhibited excellent adsorption-electrocatalytic activity and stability. Electron is the critical active species of Cr (Ⅵ) reduction.