Biocarbonation: A novel method for synthesizing nano-zinc/zirconium carbonates and oxides

It is well known that the chemical precipitation is regarded as an effective approach for the preparation of nano-materials. Nevertheless, it represented several drawbacks, including high energy demand, high cost, and high toxicity. This work investigated the eco-sustainable application of plant-derived urease enzyme (PDUE)-urea mixture for synthesizing Zn–/Zr–carbonates and –oxides nanoparticles. Hydrozincite nanosheets and spherical-shaped Zr-carbonate nano-particles were produced after adding PDUE-urea mixture to the dissolved Zn and Zr salts, respectively. PDUE not only acts as a motivator for urea hydrolysis, but it is also used as a dispersing agent for the precipitated nano-carbonates. The exposure of these carbonates to 500 °C for 2 h has resulted in the production of the relevant oxides. The retention time (after mixing urea with urease enzyme) is the dominant parameter which positively affects the yield% of the nano-materials, as confirmed by statistical analyses. Compared with traditional chemical-precipitation, the proposed method exhibited higher efficiency in the formation of nano-materials with smaller particle size and higher homogeneity.