Fig. 3: Electrochemical performance.

a Linear sweep voltammetry (LSV) curves of 1 wt% Pt-SnS₂/rGO, Pd-SnS₂/rGO, Ni-SnS₂/rGO, Cu-SnS₂/rGO, pure SnS₂/rGO, pure SnS₂, 10 wt% Pt/rGO and 10 wt% Pt/C with a scan rate of 10 mV s⁻¹ in 0.5 M H₂SO₄ solution without iR compensation. b Overpotentials at 10 mA cm⁻² and 200 mA cm⁻² of Pt-SnS₂/rGO with three different Pt loadings (~0.3 wt%, 1.0 wt% and 1.5 wt%, respectively) and commercial 10 wt% Pt/C. c The Pt-mass activities of 0.3 wt% and 1 wt% Pt-SnS₂/rGO, 5 wt% Pt/C, and 10 wt% Pt/C. d Tafel plots of 1 wt% Pt-SnS₂/rGO, 10 wt% Pt/rGO, and 10 wt% Pt/C at 10 mA cm⁻² and 100 mA cm⁻². e Polarization curves of 1 wt% Pt-SnS₂/rGO, 10 wt% Pt/rGO, and 10 wt% Pt/C before and after catalytic testing cycles. f Current density versus time (i–t) curve of 1 wt% Pt-SnS₂/rGO recorded for 72 h and 24 h at a constant overpotential of 50 mV and 88 mV vs RHE, respectively. g Comparison of the overpotential increase after a certain number of cyclic voltammetry scans between our 1 wt% Pt-SnS₂/rGO, 10 wt% Pt/rGO, 10 wt% Pt/C, other Pt single-atom catalysts, and 2D transition metal dichalcogenides (TMDs) reported in literatures.