Construction of SnNb2O6/MgIn2S4 heterojunction photocatalysts with enhanced visible-light-driven activity for tetracycline hydrochloride degradation and Cr(vi) reduction

Abstract

SnNb₂O₆/MgIn₂S₄(SNO/MIS) heterojunction photocatalytic materials were fabricated via a handy in situ growth method. Under the illumination of visible light, photocatalytic degradation of tetracycline hydrochloride (TC) and photocatalytic reduction of potassium dichromate (Cr(VI)) were used to investigate the photocatalytic performance of as-synthesized materials. The results of photocatalytic experiments showed that the prepared SNO/MIS composites had better photocatalytic performance compared with the pure samples. The apparent rate constant of TC degradation for the best sample SNO/MIS-2 was 30.3 and 3.4 times that of SNO and MIS. The apparent rate constant of Cr(VI) reduction is 498.6 and 2.5 times that of SNO and MIS. The results of cycle experiments demonstrated that the SNO/MIS-2 composite had excellent stability. The improvement of photocatalytic activity and stability was chiefly ascribed to the heterogeneous junction structure formed by the close contact between SNO and MIS, which can effectively promote carrier separation and inhibit the photocorrosion of MIS. This work provides positive guiding significance for the design and preparation of other photocatalysts for treating water pollution efficiently.