One-step synthesis of urchinlike SnS/SnS2 heterostructures with superior visible -light photocatalytic performance

Urchinlike SnS/SnS2 p-n heterogeneous composite photocatalysts were successfully synthesized by a one-step solvothermal method. The samples are characterized by XRD, XPS, SEM, TEM, BET and DRS. SnS/SnS2 (Sn/S = 39.87:60.13) heterostructure exhibited the higher photocatalytic activity, the removal efficiency of MO was 83.25% in illuminate 60 min, and degradation reaction was calculated by adopting the pseudo-first-order reaction kinetics, the k value was 3.351 x 10(-2) min (-1) which was higher than pure SnS and pure SnS2 under visible light irradiation. The mechanism of enhanced photocatalytic activity has been discussed through scavenger experiments. In addition, the main active species for degradation of methyl orange (MO) were investigated using electron spin resonance (ESR) measurement and the possible degradation pathway of MO was also presented.