Remarkable enhancement of photocatalytic hydrogen evolution over Cd0.5Zn0.5S by bismuth-doping

► Bi3+ doped Cd0.5Zn0.5S as photocatalyst and Na2S-Na2SO3 as electron donor. ► Bi3+ doping enhances markedly the photocatalytic activity for H2 evolution. ► Bi3+ doping at the Cd0.5Zn0.5S surface is beneficial.