Construction of cobalt phthalocyanine sensitized SnIn4S8/g-C3N4 composites with enhanced photocatalytic degradation and hydrogen production performance

A series of different mass ratio of SnIn4S8/g-C3N4 hybrids are fabricated via a low temperature co-precipitation method and cobalt phthalocyanine dye sensitized SnIn4S8/g-C3N4 composites (CoPc-SnIn4S8/g-C3N4) obtained through an ultrasonic impregnation method. The existence of CoPc structure over SnIn4S8/g-C3N4 sample has been characterized via XRD, SEM, FT-IR, XPS etc. The vital research of samples on photocatalytic activity is detected by the means of the diffuse reflection spectroscopy (DRS), thermal gravity and differential thermal gravity (TG-DTG) analysis and photoluminescence (PL). The results of photo-degradation activities and hydrogen production abilities confirm that 25 %-SnIn4S8/g-C3N4 composites possess better photocatalytic ability than pure SnIn4S8 or g-C3N4 sample. Besides, the 0.5844 mg CoPc sensitized 50 mg of 25 %-SnIn4S8/g-C3N4 composites (11.6‰ CoPc-25/Sn-C, mass ratio) exhibit the maximum value of H2 evolution around 636.99 μmol g−1 h−1, being 1.35 times as high as the value of 25 %-SnIn4S8/g-C3N4 composites. What’s more, during the degradation process of malachite green (MG), 11.6‰ CoPc-25/Sn-C composites possess highest kapp value of around 0.02086 min-1, which is 2.67 times as much value as the 25 %-SnIn4S8/g-C3N4 composite owns. It can be concluded that not only the incorporation of SnIn4S8 strengthen the utilization of solar energy but also the CoPc dye accelerate the rate of electron migration. Furthermore, the potential photocatalytic mechanism has been proposed.