A simple template-free bioinspired route of 1D Bi2S3 nanorods synthesis for electrochemical CO2 reduction to formate.

[Display omitted] • Development of a bioinspired process of template-free synthesis of 1D Bi 2 S 3 nanorods. • Mechanistic exploitation of Bi 2 S 3 nanorods formation mediated by plant-based analyte. • Bi 2 S 3 nanorods electrocatalyzed CO 2 conversion to HCOO^– with high Faradaic efficiency. • Oxidation of Bi 2 S 3 -NRs(bio) to Bi 2 O 2 CO 3 , could serve as active sites during ECO 2 RR. This work demonstrates a simple bioinspired route of synthesizing template-free 1D Bi 2 S 3 nanorods, Bi 2 S 3 -NRs(bio), using Sechium edule fruit. The morphology of nanorods was controlled via capping of ascorbic acid (AA), a major bio-analyte. The average length and diameter were reduced from 485 to 229.5 nm and 123 to 31 nm, respectively, compared with Bi 2 S 3 -NRs(control), Bi 2 S 3 nanorods synthesized in the absence of bio-extract/reducing agent. The XPS analysis confirmed that the formation of Bi 2 O 3 in Bi 2 S 3 -NRs(control), could be prevented in Bi 2 S 3 -NRs(bio) because of AA capping. A plausible mechanistic route of synthesis of Bi 2 S 3 -NRs(bio) is also proposed herein. The modified Bi 2 S 3 -NRs(bio)/Toray carbon paper (TCP) electrode exhibited selective HCOO^– formation with FE of 92.3% against 50.9% for the Bi 2 S 3 -NRs(control)/TCP electrode at −1.5 V (vs. Ag/AgCl). Higher FE exhibited by Bi 2 S 3 -NRs(bio) catalyst has resulted from its compositional and morphological attributes. In-situ electrochemical oxidation of Bi 2 S 3 -NRs(bio) to Bi 2 O 2 CO 3 also could act as active sites for enhanced and selective HCOO^– formation. [ABSTRACT FROM AUTHOR]