Surfactant-modified Zn nanosheets on carbon paper for electrochemical CO 2 reduction to CO.

We report a strategy that tunes the CO 2 and proton concentrations near the electrode-electrolyte interface using surfactant modification with various amounts (0.05, 0.8, 1.6, and 3.2 mg) of hexadecyl trimethyl ammonium bromide (CTAB). The positively charged group of CTAB favors CO 2 surface diffusion and inhibits excessive proton accumulation on Zn nanosheets on carbon paper. A CO faradaic efficiency of 95.6% and a total ampere density of -13.1 mA cm -2 were obtained over the optimal CTAB-modified Zn electrode at -1.1 V with stability over 12 hours.