Fig. 5: Perovskite|CuNF–Si PEC devices coupling unassisted C2 hydrocarbon synthesis to GOR.
From: Perovskite-driven solar C2 hydrocarbon synthesis from CO2
a, A schematic illustration of the PEC device wiring a NW Si photoanode to a PVK|CuNF photocathode. b–d, SEM images of the SiNW array photoanode: cross-section (b), top view of NW array (c) and PtAu GOR catalyst (d). e, CV traces of CO2RR, GOR and OER (photo)electrodes. The sign is reversed for cathodic traces. f,g, FYs of Si-PVK|CuNF PEC devices with different CuNF geometric areas for CO2 reduction (f) and GOR (g). The high photocurrent and early onset potential of the SiNW photoanode shifts the bias-free operating point of PEC devices to 0.1–0.2 V versus RHE. As a result, the C2 hydrocarbon selectivity resembles that of PVK|CuNF electrodes at 0 V versus RHE (Fig. 3b). h, CPE of a SiNW-PVK|CuNF (4 mm2) device. i, CV traces of Si-PVK|CuNF devices with different CuNF areas. Two-hour CPE is performed at 0 V applied bias under 1 sun irradiation (AM1.5 G, 100 mW cm−2), at room temperature, under stirring. A bipolar membrane separates the CO2 saturated 0.1 M KHCO3 solution (pH 6.8) on the cathodic side from a 1 M KOH, 0.1 M glycerol solution (pH 13.7) in the anodic compartment. In e and i, lighter shades indicate chopped light CV traces. Average values were calculated from sample triplicates, with error bars corresponding to the standard deviation.
