Binding characteristics of CoPc/SnO2 by in-situ process and photocatalytic activity under visible light irradiation

Cobalt phthalocyanine (CoPc) was synthesized and self-assembled on the surface of nanoscale tin dioxide (SnO2) by in-situ process, marked as i, and Co-O interaction was verified to conjugate axially between macromolecule (CoPc) and SnO2 in CoPc/SnO2(i). The results indicated that the binding constant of CoPc/SnO2(i) was two-order higher than that of CoPc/SnO,(d) synthesized by dipping process, marked as d, while the numbers of binding sites were comparable in both samples. The degradation rate in the photocatalytic activity of CoPc/SnO2(i) was 32.5% higher than that of CoPc/SnO,(d) under visible-light irradiation for 150 min due to the effective electron separation and energy injection from LUMO of CoPc to conduction band of SnO2 for CoPc/SnO2(i) based on the strong interaction between CoPc and SnO2. The degradation recyclability of CoPc/SnO2(i) retained 48.8% in 10 times under the same circular photocatalytic process.