The synthesis of Cd1–x
Mn
x
S solid solutions (x = 0.0,
0.25, 0.5, 0.75, and 1.0) has been achieved through a facile hydrothermal
route. Because of the limited mutual solubility between CdS and γ-MnS,
the incorporation of Mn2+ into CdS lattice simultaneously
produced CdS-hosted Cd1–x
Mn
x
S and γ-MnS-hosted Cd1–x
Mn
x
S phases during the
hydrothermal synthesis of Cd1–x
Mn
x
S solid solutions, especially at x = 0.5. The Cd1–x
Mn
x
S solid solutions with the coexisting dual
phases exhibit remarkably higher photocatalytic H2 evolution
from water splitting than pristine CdS. The influences of the incorporation
of Mn2+ into the CdS lattice on the phase structure and
compositions, morphologies, BET surface area, band structures, semiconductor
characteristics, photoinduced charge separation, and resulting H2 evolution were investigated in detail. It was well revealed
that the coexistence of CdS-hosted Cd1–x
Mn
x
S and γ-MnS-hosted Cd1–x
Mn
x
S
phases in the solid solutions constructs the p-n heterojunctions with
an appropriate band alignment, which effectively facilitates the transfer
and separation of the photogenerated charges for the highly efficient
H2 evolution. Moreover, the charge separation and photocatalytic
H2 evolution over the Cd1–x
Mn
x
S solid solutions can be further
improved by the deposition of Ni(OH)2 as a cocatalyst.