Bio-inspired mineralization of CO2 to nanoscaled hydrozincite mediated via Zea mays saccharata

Abstract The bio-inspired mineralization of CO 2 to single-phase Hydrozincite Zn 5 (CO 3 ) 2 (OH) 6 was demonstrated for the first time in this contribution utilising aqueous extracts of Zea mays saccharata (ZMS). The latter has been a successful chelating and capping agent. Under ambient circumstances (room temperature & atmospheric pressure), this novel method produced single-phase crystalline hydrozincite Zn 5 (CO 3 ) 2 (OH) 6 with an average crystallite size of 38.5 nm. The UV–VIS–DRS, PL, FT-IR, XRD, and SEM–EDS studies sustained the potential of the bio-engineered nanoscaled Hydrozincite Zn 5 (CO 3 ) 2 (OH) 6 as a highly reflective material (Diffuse reflectance > 95%) and an effective blue luminescence (λ MaxEmission ≈ 457.3 nm). Electrochemical properties were investigated in 1 M NaOH electrolyte using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). CV studies demonstrated a significant increase in current response with distinct Faradaic peaks at + 0.07 V, + 0.18 V, and − 0.16 V (vs. Ag|AgCl), confirming the inherent electrochemical activity and surface redox behaviour of the nanoparticles. This was further corroborated by EIS, which showed a substantial reduction in charge transfer resistance (R ct ) from 845.84 kΩ for the bare glassy carbon electrode (GCE) to 94.30 kΩ for the Zn 5 (CO 3 ) 2 (OH) 6 modified GCE, indicating enhanced charge-transfer kinetics. These results demonstrate a bio-engineering route for synthesizing single-phase crystalline hydrozincite Zn 5 (CO 3 ) 2 (OH) 6 nanoparticles with favorable opto-electrochemical properties, including enhanced electrochemical behaviour and charge transfer characteristics. Furthermore, the study demonstrates the feasibility of CO 2 mineralization to hydrozincite under ambient conditions.