Based on the density functional theory, the photocatalytic water splitting reaction has been studied over the monolayer MoS2 alloying with MoSe2, MoTe2 and WS2 under stress condition. The calculated results show that the monolayer MoS2 alloyed with MoSe2, MoTe2 and MoWS2 under the compressive stress condition can increase the band gap and improve the position of CBM (conduction band minimum) band edge to enhance the efficiency of photocatalytic water splitting. The calculated energy band and density of states show that the alloy elements form energy band instead of isolated energy level, which has little effect on carrier life.
