Using ammonia and Co(CH3COO)2·4H2O as starting materials, a facile and surfactant-free route to controlled synthesis of Co3O4 nanoparticles was proposed. Co3O4 nanoparticles with average sizes of 3.5, 6, 11, 19 and 70 nm were obtained through adjusting the ethanol amount in the solvent (the ratio of ethanol to water) or the concentration of raw materials. In this process, the presence of enough O2 was crucial for the formation of pure Co3O4 phase. The environmental catalytic properties of as-obtained Co3O4 nanoparticles were investigated. The results indicated their remarkable catalysis for ozonation degradation of phenol, which denoted a promising application as catalyst in waste-water treatment.

Synthesis of two lignin derivatives, lignophenol and lignin-aminophenol, were presented in this article. The chemical structure and the func-tional groups of lignin derivatives were charac-terized through FT-IR analysis. The immobiliza-tion of three proteases (papain, trypsin and pepsin) on lignin and lignin derivatives was carried out using adsorption technique. The influence of contact time and pH on the enzyme adsorption by different adsorbents was inves-tigated. Furthermore, enzyme activity recovery was also evaluated. Results showed that lignin and lignin derivatives could adsorb proteases effectively and the adsorption capacity of lingo- phenol and lignin-aminophenol was higher than that of pure lignin. Meanwhile, the activity re-covery of papain and pepsin immobilized on lignin derivatives was very high. This pheno- menon suggested that there is a supramole- cular interaction between enzymes and lignin derivatives which do not inhibit enzyme activity. Therefore, lignophenol and lignin-aminophenol are both promising adsorbents for enzyme im-mobilization under acid and neutral conditions