Preparation of 26-facet Cu2O@Cu composite and its methyl orange adsorption behavior

Abstract A core–shell structure that can achieve effective adsorption of methyl orange (MO) can be prepared by using 26-facet Cu2O as a template for producing copper using a reducing agent. However, there are insufficient studies on this topic. Therefore, in this study, Cu2O@Cu composites were synthesized using a two-step liquid-phase reduction method. MO was used as a pollutant to test the adsorption properties of the materials. The adsorption experiments showed that the adsorption process followed pseudo-first-order kinetic and Freundlich isotherm. The maximum capacity of the adsorbent was 498 mg/g, and the adsorption occurred via spontaneous and exothermic physical adsorption. By the comparation of adsorbent before and after adsorption, it was found that the content of Cu+ decreased and that of CuO increased, indicating that the material was oxidized during the adsorption process. Further, FTIR spectroscopy and zeta potential showed that the adsorption mechanism was the electrostatic attraction between positively charged adsorbent and the sulfonic acid group of the MO. Therefore, the porous core-shell structure and the positively charged adsorbent facilitated the adsorption of anionic dyes. 1TD can be used as an effective adsorbent for MO.