For the case of HER, although the occurrence of hbn topology is practically unchanged in the filtered COFs (2.3% of occurrence in all COFs, 2.7% in the filtered ones for HER), we noticed an increase in the occurrence of hca (64.5% of occurrence in all COFs, 75.7% in the filtered ones for HER), hcb (6.4% of occurrence in all COFs, 10.8% in the filtered ones for HER), and fes (5.0% of occurrence in all COFs, 10.8% in the filtered ones for HER). In the literature, COFs that have been reported for HER oftentimes display honeycomb (hcb and hca) topologies. Our findings suggest that fes nets could be another possible direction of exploration for photocatalytically active COFs.