“…X-ray absorption near edge structure (XANES) of Pt L-edge shows that the white line peak of Pt SAs-Pt NCs/NSC catalyst is between Pt foil and PtO 2 , indicating that the valence state of Pt in Pt SAs-Pt NCs/NSC catalyst is between 0 and +4 (Figure 2b), and the valence state of Pt atoms is further determined to be 1.36 by oxidation state fitting (Figure 2d). From the Fourier transform (FT) k 3 -weighted extended X-ray absorption fine structure spectrum (EXAFS) of Pt SAs-Pt NCs/NSC catalyst (Figure 2c,e), there is a main peak at 1.5 Å, belonging to Pt-N/S coordination, [35,36] and a low peak at 2.5 Å, belonging to metallic Pt-Pt coordination, , d) LSV curves before and after durability test for 5000 CV cycles (the inset is i-t curves), e) partial HER performance comparison of the overpotentials at 10 mA•cm −2 and Tafel slopes of Pt SAs-Pt NCs/NSC with recently reported catalysts, [16,28,[37][38][39][40][41][42][43][44][45][46][47][48] and f) partial HER activity comparison of the TOFs of Pt SAs-Pt NCs/NSC with recently reported catalysts. [15,28,44,[49][50][51][52][53][54].…”