Preparation and properties characterization of Co-Mn doped carbon aerogels

In order to investigate the effects of the different carbonization temperatures on the electrocatalytic hydrogen evolution properties of the Co-Mn-doped carbon aerogel (Co-Mn/CA), the Co-Mn/CA was prepared by hydrothermal method using resource-rich and renewable lignocellulose as a carbon source, cobalt acetate tetrahydrate as a cobalt source, and manganese acetate tetrahydrate as a manganese source. The results reveal that after carbonization, the surface morphology of the cellulose aerogel changes from a laminated structure to a porous structure, which increases the active sites and electrocatalytic hydrogen evolution activity. After characterizing the structure by XRD and N₂ adsorption and desorption, it shows that CA product after carbonization is almost amorphous carbon and the CA after carbonization at 900℃(CA-900) has the largest specific surface area and total pore volume of 958 m²·g^-1 and 0.33 cm³g^-1, respectively. The electrochemical performance tests show that the Co-Mn/CA-900 has the best electrocatalyst hydrogen evolution reaction (HER) activity. In 1 mol/L KOH electrolyte, it has an overpotential of 175 mV at a current density of 50 mA·cm^-2 and the pressure drop is only 7% after chronopotential test for 10 h, which indicates superior electrocatalytic hydrogen evolution stability.