Electrochemical CO₂ reduction reaction (CO₂RR) is a promising way to achieve carbon neutrality. However, the activity and selectivity of CO₂RR are limited by not only the development of earth-abundant catalysts but also the CO₂ mass transfer during the CO₂RR process. Herein, Bi₂S₃ nanorods were synthesized under a relatively mild route. Furthermore, benefitting to the modulation of the hydropathy, the optimized sample (BS-P1) achieved a Faradaic efficiency of HCOO⁻ (> 90%) in the range from − 0.9 to − 1.2 V, a high current density of HCOO⁻ (2.29 times larger than that of BS-P0 at − 1.2 V) and a prolonged stability from 12 to 20 h at − 1.1 V. When the temperature decreased from 25 to 0 °C and eventually to − 20 °C, the reaction kinetics of CO₂RR was slowed down, the distribution of products was changed and hydrogen evolution reaction (HER) was inhibited. This work provides a facile synthesis for Bi₂S₃ and highlights the importance of triple-phase interfaces in CO₂RR.

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