Fig. 4: Activity for solar hydrogen production.

a Comparison of hydrogen production activity on six relevant samples. b AQY values measured under different incident wavelengths for pure Cu7S4 and 5-Au@Cu7S4. c Hydrogen production activity on pure Cu7S4 and 5-Au@Cu7S4 with and without additional visible irradiation. d Extended use of 5-Au@Cu7S4 in solar hydrogen production for 30 successive hours.