Photoanode driven photoelectrocatalytic system for CO2 reduction to formic acid based on lattice-dislocated Bi nanosheets cathode†
Abstract
In the context of carbon neutrality, the efficient conversion of CO2 is an ideal approach to solving current environmental deterioration and energy shortages. Conversion of CO2 to HCOOH through a photoelectrochemical (PEC) approach is efficient and green. However, achieving efficient PEC reduction of CO2 to HCOOH within a wide potential window remains a challenge. In this work, the photoelectrochemical system was constructed using a CxNy/BiVO4 photoanode and lattice-dislocated Bi (LD-Bi) nanosheets to achieve efficient and stable PEC reduction of CO2 to HCOOH. The PEC tests indicated that the Faraday efficiency of HCOOH (FEHCOOH) of the system was up to 93.8% at a cell voltage of −2.2 V, and FEHCOOH still maintained 85.7% after five cycles of experiments. Under the optimal cell voltage of −2.2 V, the system achieved excellent stability for 10 h. In addition, a series of electrochemical characterization techniques indicated that the improvement of water oxidation performance is conducive to the efficient reduction of CO2 to HCOOH. Based on Bi-based nanomaterials, the work achieves an efficient reduction of CO2 to HCOOH through the synergistic effect of photoanode and cathode, which provides certain ideas for efficient conversion of CO2.