The authors regret that there was a unit conversion error in Fig. 2 (a). The correct version of Fig. 2 is shown below. Accordingly, the sentence beginning ‘‘Furthermore, based on the results in Fig. 2’’ on page 2887 is incorrect. The correct sentence is as follows: ‘‘Furthermore, based on the results in Fig. 2, the total nitrogen fixation rate increased from 22.3 mmolmin1 (ex situ) to 51.1 mmolmin1 (in situ), which also showed improvements compared with the other reported ex situ synthesis with a similar reaction area.’’ The figure now matches with the rest of the publication, which all have the correct units. [Figure Presented]. The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.