Fig. 5: Comparison of the Cu cube behavior at different loadings.

We compare nominally 390 nm Cu cubes at high loading (a) at the same potential. In b, we compare the partial current density for the gas products of the high loading sample (390 nm Cu cube size) normalized by the initial loading. We have observed a higher overall current (c) and more C2+ gas and liquid products (b, d) at higher loading at −1.1 VRHE. The error bars give the standard deviation of three measurements.