fig4

Figure 4. (A) Calculated free energies of H₂O adsorption, activated H₂O adsorption, OH adsorption and H adsorption. Copyright 2017, The Authors, published by Springer Nature^[71]. (B) Non-volatile solid carbon precursors (for example, CNT) may have different impacts on the chemical composition and microstructure of the carburization product. Copyright 2016, The Authors, published by Springer Nature^[79]. (C) Comparison of the overpotentials required at 10 mA cm^-2 among our catalyst and available reported HER catalysts. (D) Comparison of the current densities delivered at -200 mV among our catalyst and available reported HER catalysts. Copyright 2018, The Authors, published by Springer Nature^[94].