In-situ synthesis of mesoporous TiO_2-Cu_2ZnSnS_4 heterostructured nanocomposite for enhanced photocatalytic degradation

摘要

In this study, a n-p type mesoporous TiO2-Cu2ZnSnS4 heterostructured photocatalyst was synthesized by single-step in situ hydrothermal route and characterized by XRD, Raman, SEM, HRTEM, FT-IR, BET, DRS and XPS. The results show that the introduction of CZTS extends the light absorption of TiO2 into visible region, which led to increase in physically absorbed oxygen and surface hydroxyl group and subsequently diminished the recombination rate of photo-generated charge carriers. The photocatalytic activity of nanocomposites was investigated by degradation of rhodamine B (RhB) and methyl orange (MO) under the visible-light irradiation. The visible-light driven photo-degradation improved remarkably with TiO2-CZTS as photocatalyst and no significant change in crystalline phase and surface morphology of heterostructured nanocomposite was observed. Furthermore, the results confirm that the photo-degradation by TiO2-CZTS photocatalyst obey the first order kinetics with apparent rate constant (k(app)) of 0.0551 min(-1) (RhB) and 0.01733 min(-1) (MO) with the half time period (t(1/2)) of 12.48 min and 39.99 min, respectively, and propose that the p-n type TiO2-CZTS heterostructured photocatalyst could emerge as a promising candidate for environmental remediation applications.